Archaeologists have uncovered a rare and unusual burial of premature twins in a 1,200-year-old tomb near the Temple of Artemis at Ephesus in Turkey. Although the burial was found in an abandoned latrine, researchers think the intention was to protect the babies in the afterlife.

"This interment was made in an unexpected and exceptional setting," Lilli Zabrana, an archaeologist at the Austrian Academy of Sciences who co-authored a new study detailing the discovery, told Live Science in an email. Burials previously discovered at Ephesus were made in a dedicated cemetery outside the boundaries of the ancient temple.

"What is even more unusual is that the burial contains two premature infants, who were probably twins, which is a rather rare occurrence," study co-author Caroline Partiot, a bioarchaeologist at the Austrian Academy of Sciences, told Live Science in an email. Evidence of a rare genetic condition found in one of the infants makes the finding even more unique, the researchers noted.

In the study, published online July 13 in the journal Childhood in the Past, Partiot and Zabrana analyzed bones found in a tomb that was likely built in the eighth to ninth century, during the middle Byzantine era. The grave was placed within an abandoned latrine channel, originally built during the second or third century, Zabrana said, but the latrine was a later addition to a Roman odeum — a building used for musical performances — that was built in the first century within the sacred area of the famous Temple of Artemis at Ephesus (one of the Seven Wonders of the Ancient World), which was originally built around 550 B.C.

When excavators opened the cist, or stone-lined grave, they saw two tiny skeletons buried side by side. Based primarily on the size of the bones, Partiot and Zabrana estimated the skeletons were from infants who were likely born prematurely at around 33 to 34 gestational weeks, or 7.5 months in utero. (A full-term pregnancy typically lasts between 39 and 40 weeks.)

"The hypothesis that they were twins is based on the fact that they have very similar ages at death and were buried in direct contact with one another," Partiot said. "However, it will only be possible to confirm whether they were indeed twins through future DNA analyses."

Although the researchers did not find any evidence of trauma or disease on the babies' skeletons, they did notice a rare bone called a supernumerary cervical rib. This hereditary trait involves the growth of an extra rib bone that forms at the back of the neck in about 1% of people and usually doesn't cause any problems. However, Partiot has found that, in babies, there is an association between cervical ribs and anomalies in Hox genes — a group of genes that code for specific body parts during embryonic development — that can lead to stillbirth, prematurity or sudden infant death.

"To the best of our knowledge, no cases of twins with cervical ribs have been documented in an archaeological context" before this one, the researchers wrote.

The twins may have been buried in an odd location outside the known burial grounds at Ephesus because they died as premature infants who probably hadn't been baptized yet, the researchers proposed. The infants' final resting place was likely a kind of "practical compromise" between Christian burial practices and local customs, the researchers wrote in the study.

The team found no evidence of the twins' mother nearby or in the Ephesus cemetery. "It is possible she died at the same time, but it is also possible that she did not; it is difficult to say," Partiot said. "Both infant mortality and maternal mortality were very high at the time."

But the twins' protective cist grave preserved their skeletons for more than a millennium, which "clearly indicates that this was a respectful burial rather than the disposal of human remains," Zabrana said. Ultimately, the tomb reveals a family's "intention to care for the two deceased infants in death, and to acknowledge their fleeting place within the community," the researchers wrote.

What do you know about the bones in your body? Test your knowledge with our human skeleton quiz.

Inca boys and girls chosen for human sacrifice trekked through Inca communities for thousands of miles on sacred pilgrimages before their ritual deaths, often near high peaks in the Andes Mountains, a new analysis of their mummies reveals.

The research also looks again at the manners of their deaths and found that none of three children in the Inca ritual, known as Capacocha, died in the ways that scientists previously thought.

"Capacocha was not limited to the final act of offering at the mountain," study first author Verónica Silva-Pinto, an archaeologist at Diego Portales University in Santiago, Chile, told Live Science in an email. "It was an extended ritual process that began months earlier and involved mobility, dietary changes, the participation of different communities, and the creation of sacred landscapes."

But some other experts, while welcoming the study, are cautious about some of its details.

The new study is based on new examinations of three Capacocha mummies from two sites: The "Niño de El Plomo" or El Plomo Boy, who was about 8 or 9 years old in the 15th century when he was sacrificed near the 17,700 foot (5,400 meter) summit of Cerro El Plomo, now in central Chile; and two girls, one about age 9 and the other about 18, who were sacrificed about 30 years earlier near the top of what's now Cerro Esmeralda in northern Chile's Atacama Desert.

It was long thought that the El Plomo boy had died from hypothermia, or exposure to freezing temperatures, on the high peak, and that the Cerro Esmeralda girls were killed by strangulation. But the new study, published July 15 in the journal Science Advances, rejects those ideas.

Human sacrifice

Archaeologists found the El Plomo Boy in 1954 and the two Cerro Esmeralda girls in 1976. The new study applies modern archaeological techniques to them for the first time.

It "demonstrates that previously investigated contexts can continue to provide crucial information when revisited using new technologies, minimally invasive methods, and an ethical perspective," Silva-Pinto said.

Their examinations with CT scans and microscopy revealed that El Plomo Boy had been killed with blunt force trauma to the head — an injury that wasn't apparent to the initial investigators. The two Cerro Esmeralda girls, meanwhile, were previously thought to have been strangled because of marks on their necks. But the new study found that the marks were probably caused by their clothing after death, and that the hyoid bones of their throats were not fractured or displaced, which happens in most strangulations. The cause of the girls' deaths should now be considered "indeterminate," the researchers said.

Silva-Pinto said the forensic examination should be considered within the Andean worldview, which didn't see death as the end of existence.

"Death was not necessarily understood as an absolute end, but rather as a transformation or passage into the realm of divinities, ancestors, and sacred forces," she said. "The individuals who were offered acquired a new ritual status and could become mediators between communities, mountains, divinities, and the state."

Sacred pilgrimage

The researchers carried out chemical studies on tiny samples of hair from the mummies by looking at isotopes, or different versions of the same element that have varying numbers of neutrons in their nuclei. The isotopes from food and water people consume are incorporated into their hair, shedding light on where they've lived. The team also examined samples of fractured bones for radiocarbon dating.

The hair isotopes showed that the children had moved over long distances between "ecologically distinct regions." The researchers estimated that El Plomo Boy traveled between 1,615 and 1,740 miles (2,600 and 2,800 kilometers) over his last nine months, probably starting from the Inca capital Cuzco, at the heart of the Inca Empire. The Cerro Esmeralda girls probably traveled between 560 and 745 miles (900 and 1,200 km) in their final three months.

Silva-Pinto said the pilgrimages connected outlying regions with the high mountains and other sites where the ceremonies culminated. "Along the routes, local communities would have received the pilgrims and participated in ceremonies involving the sharing of food and beverages," she said. The routes thereby became sacred landscapes, and the central Inca state used this to consolidate its presence in incorporated territories, she said.

The radiocarbon dates for the mummies showed they were all sacrificed in the 15th century: the Cerro Esmeralda girls in about 1450 and El Plomo Boy in about 1480. "The chronology shows that these were not isolated events, but rather a practice carried out at different moments," Silva-Pinto said.

Bioarchaeologist Dagmara Socha from the University of Warsaw in Poland, who studies the Capacocha mummies but who was not involved in this particular examination, cautioned that the conclusions drawn from the isotope analysis might be flawed. "Isotopic analyses alone do not allow us to reconstruct the potential route taken during the journey," she told Live Science in an email. "In several cases, the observed isotopic changes were not statistically significant and may also reflect seasonal variation in diet."

The study is "interesting and potentially valuable, but some of the interpretations go beyond what can be reliably concluded from the available evidence," she told Live Science in an email.

Archaeologist Pablo Mignone of Argentina's Institute for Research in Social Sciences and Humanities, who was also not involved, said the paper's interpretive framing could be questioned. "The paper leans on a fairly centralized, top-down narrative: children brought to Cuzco and then dispatched as instruments of 'biopolitical conquest,'" he told Live Science in an email.

But earlier studies showed that Capacocha individuals sometimes started their trek in Inca regions, not only at the capital: '''Cuzco as the sole engine of conquest' is an interpretive choice that neither this study nor the broader body of comparative evidence on Capacocha unequivocally supports," Mignone said.

How much do you know about the first people to reach the Americas? Find out with our First Americans quiz!

Fifty years after Southern California's Salton Sea formed due to an engineering mishap in 1905, the giant salt lake became a booming vacation destination. Nicknamed the "miracle in the desert," the lake offered watersports and boating, while its shores were lined with yacht clubs, vacation homes, shops and nightclubs.

However, by the 1970s, the Salton Sea had begun shrinking due to high evaporation rates and flow reductions in the Colorado River, which had fed the lake. The lake's retreat exposed muddy sediments imbued with pesticides and other agricultural chemicals from large cotton, alfalfa and vegetable farms in the Imperial and Coachella valleys.

Today, the Salton Sea is a ghost of its former self, but the lake looms larger in the lives of local residents than ever before. Its shrinking shoreline releases toxic particles so tiny that they can penetrate deep into human lungs and enter the bloodstream. Exposure to these particles can raise the risk of a range of respiratory and cardiovascular conditions, including asthma, impaired lung function and heart attacks.

The communities most affected by this pollution are low-income, racial and ethnic minorities that, for socioeconomic reasons, cannot move away or adequately protect themselves.

A study published July 1 in the journal BMC Environmental Science reveals just how bad living conditions are for some communities near the Salton Sea. The authors examined air quality and respiratory health in Latinx and Indigenous Mexican families in the Eastern Coachella Valley, finding that families must change their daily routines to protect themselves from harmful dust events.

To find out more, we spoke with study co-author Ann Cheney, a professor of social medicine, population and public health at the University of California, Riverside School of Medicine. Cheney, who oversees a free clinic for underserved minority communities in the Eastern Coachella Valley, described the daily struggles of families living near the Salton Sea and some of the measures that are needed to improve their quality of life.

Sascha Pare: The Salton Sea has shrunk by 65 square miles (168 square kilometers) and dropped by 14.6 feet (4.5 meters) over the past few decades. Why is that, and how does it affect local residents?

Ann Cheney: The Salton Sea occupies an ancient lake bed that, over the millennia, has been filled, and then dried up again. In the early 1900s, because of an engineering mistake, part of that lake bed filled, and it created the Salton Sea. [Editor's note: The sea formed when Colorado River floodwater breached an irrigation canal that was under construction in the Imperial Valley.]

Then, over decades, there were changes in the composition of the sea because the main source of water was agricultural runoff. The sea is located in the inland southern Californian desert region. In the 1940s and 1950s, there was a boom in agribusiness. This remade the landscape, and all of those chemicals and pesticides from the agricultural land seeped into the lake bed.

With [water management] decision-making around the Colorado River waters, that then meant that another source of water, which had been the Colorado River, ceased to enter into the Salton Sea. 2018 was the last time that water from the Colorado River touched the Salton Sea.

Because there is the primary source of agricultural runoff going into the sea and no new fresh water coming in — and with climate change [boosting evaporation] — it's created this environment in which you have a drying sea. Over decades, there have been chemicals and heavy metals seeping into the playa [dry lake bed], and now it's exposed. It's the desert, so there's a lot of dust storms, and the winds take the exposed playa and bring it into the air, which is then breathed by the local residents.

For me, what's most concerning is that the local residents who are most affected by the poor air quality are Latinx and Indigenous Mexicans, many of whom are undocumented and have very little political voice.

SP: You asked caregivers of children with asthma and other respiratory conditions to document their experiences of living near the Salton Sea. What did those submissions reveal?

AC: When I first started doing this work, I thought about it as solely the Salton Sea [affecting people]. But it's the environment in which the Salton Sea is one contributor to poor air quality [that impacts local residents].

The caregivers perceive the Salton Sea as being a contributor to the poor respiratory health of their children. But also, this area has many disenfranchised communities that are interspersed on tribal lands, and there are different rules on these tribal lands. There is a lot of dumping and a lot of burning of trash. What we heard from caregivers is that it's not just the exposure to the toxic dust, but also the fires [that are causing issues].

In that article that we published [July 1 in BMC Environmental Science], there was an incident in which there was a fire — I think it was related to tire burning — in very close proximity to one of the apartments that one of the caregivers and her family were living in. These things happen commonly. So, from the perspective of the caregivers, there are multiple different factors that contribute to their children's poor respiratory health.

SP: Can you take me through a day in the life of one of these caregivers, based on the evidence you gathered?

AC: It could be a beautiful day. The caregiver walks outside. It's sunny; everything's beautiful. In my opinion, this environment is very beautiful. Maybe, later on in the day, there is a pickup of wind, and there's dust. Let's say the caregiver is a mother with a child who has asthma who's at school. The children are outside on the playground. Her child is going to be highly affected by the dust that's being picked up by the wind. What's going to happen is, the school will bring the child inside, and if the child doesn't have too severe of a respiratory distress, the child could stay at school. Otherwise, the caregiver will get called and have to come to school and pick up their child.

Most folks in that region are farm laborers. They're not owners of farms; they are the ones who are working the land for the owners. Many individuals who are living in very impoverished conditions — for instance, the Purépecha community, which is the Indigenous community we worked with that's from Michoacán in Mexico — are pickers. They are in the lowest-social-ranking jobs within farm labor, and, in part, that's because they may be monolingual Purépecha. That means they don't speak Spanish or English, and that limits the type of employment they can have.

In a situation where you have this very precarious employment, if your child needs to be taken out of school and you are the caregiver, then you risk losing your job. That's the type of dynamic that's at play among many of the families that we work with.

SP: What are the long-term consequences of living day after day in these conditions?

AC: It's a really poor quality of life for children, especially. There's a picture that a caregiver took of her child that I think exemplifies so well the experience of children and their quality of life. The child is just lying on the floor in their home. The photo illustrates the child's lethargy and the boredom and the fact that caregivers often choose to have their children stay inside, because they can better control the indoor air quality. They can't necessarily control what's going to happen outside, but they can control indoor air quality.

The problem is, if the family doesn't have the resources to have an air filter to clean and purify the air, for instance, then what we've noticed in our research is that there can still be very poor indoor air quality, particularly when there's more extreme weather events like fires or dust storms.

With the research, I anticipated very poor quality of life for children. But what I understood less was that it also means poor quality of life for their families, and particularly for mothers, who are often the primary caregivers. It really affects their mental health and well-being.

SP: Currently, are there any measures in place to protect these families?

AC: There has been Assembly Bill 617, which was a measure to engage members of the communities that are most affected by the Salton Sea environment in a process of mitigating the effects of the sea. From that, there have been a lot of community meetings. Years ago, I started to participate as one of the advisory board members. It became a bit frustrating — and I think this illustrates the history of frustration in this region — because government entities come in with resources and money. But it's very top-down, and often the community gets upset and frustrated because they don't see these agencies making changes in the community. There's a lot of talk and very little action.

There are also monies that have been dedicated to Salton Sea restoration, and there's been an ongoing conversation about a 10-year plan to mitigate the effects of the drying of the sea. But the focus has been primarily on wildlife, not human health. Only more recently have there been conversations about human health and the public health implications.

For individuals who have a specific diagnosis of asthma, they may qualify for retrofitting. That means they will receive money through their health insurance to be able to invest in improving their home. That might mean taking out carpet [which can capture dust], or maybe fortifying windows or doors ‪—‬ things like that. But it's a really small amount of money. It can help to a certain degree, but I think in this community, in particular, they may not always know how to navigate the healthcare system to get access to that type of resource. In addition, the most vulnerable people in this community don't have access to health insurance.

SP: What more could be done to improve people's quality of life in this community?

AC: We installed air-quality monitors in people's homes, and we spent a lot of time collaborating with communities in this region. Some live in apartment complexes; some live in single-family homes. But the majority live in mobile home parks, in which they're living in very old, dilapidated trailers. The land is dirt. It's an area that is very impoverished.

So, when I think about these communities, in particular, they can't protect themselves from the external environment. In terms of policies, [I wonder] how we can put money toward building housing that is not trailers and can really protect people from the dust. Right now, the wind is bringing dust into the homes. We need to find ways to actually keep the homes sealed.

SP: The Salton Sea is a hotspot for lithium, and although there are currently no active lithium mines in the region, policymakers and private companies are investigating the sea's potential to host one. How might lithium mining affect the families you worked with?

AC: That conversation's been going on for several years now. At the moment, it's not as much a community concern, because there's been very little movement [to open mines]. There was a lot of action and movement about three or four years ago. But it's been a few years since they've been testing the prototype, and it doesn't seem like it's gone to scale, where they would have been able to commercialize it.

Initially, the community was quite upset, because it's just another example of the lands being exploited and other people benefiting. Typically, the beneficiaries are individuals who are not originally from the community and who have professional degrees. They get the resources, and they get to make decisions about the resources. Then, the conversation was, "Well, but if we have this type of business coming in, then it can create jobs." But we know that it creates jobs for individuals who have professional degrees, or they'll have to get some type of training; they're not jobs for farmworkers or individuals who are undocumented.

It takes a lot of water to do lithium mining, so that also has implications for the continuation of the shrinking of the Salton Sea.

SP: Other lakes around the U.S., including Utah's Great Salt Lake, are shrinking and exposing toxic sediments that are then blown into residential areas. Do those drying lakes have similar effects on local communities?

AC: There is a film director [Abby Ellis from around the Great Salt Lake] who, I think two years ago, came to the Eastern Coachella Valley and met with myself and my team members. She said, "I want to get a sense of what's going on here, because this is essentially where we are going to be 10 or 15 years from now."

I had the opportunity to very briefly chat with her, but also view the trailer for her documentary. One of the distinctions between the communities surrounding the Great Salt Lake and the Salton Sea is the color of the skin of those living around these bodies of water. In Utah, it seems to be more so individuals who maybe are middle class, or have a certain access to resources — people who can have a political voice and organize and say, "We don't want this to happen." It will be interesting to see if there can be more change in communities where there are more affluent people living near these bodies of water.

This interview has been condensed and edited lightly for clarity.

The fragile and battered remains of an infant who lived about 6,000 years in Mesopotamia may be the oldest documented case of child abuse from the Middle East and one of the oldest known cases of its kind in the world, a new study finds.

Researchers unearthed the infant's remains in Syria, but at the time the infant died, sometime between 4200 and 3900 B.C., it was buried in Tell Brak, one of the world's earliest cities. It's possible that the difficulties associated with early urbanization played a role in the child's abuse, the researchers noted.

The team determined that, based on the infant's tooth development, the child was 6 to 9 months old at death. An analysis of the remains, which were interred in a children's burial ground within a Late Copper Age workshop district, revealed that the infant had four fractured ribs near the breastbone. The right thigh bone had abnormal growth, while both sides of the skull bore active, porous lesions. These injuries point to the bones being subject to intense and repetitive external forces, and the nature of the lesions don't fit easily with an accidental fall, the researchers said.

"Ribs shouldn't break" in such a small child, study co-author Aleksandra Grzegorska, a bioarchaeologist at the University of Warsaw, told Live Science. Although rib fractures are relatively common in adults, they suggest child abuse in young infants, she said.

In the study, published May 21 in the International Journal of Osteoarchaeology, Grzegorska and her colleagues systematically ruled out other explanations for the injuries, including rickets, scurvy, birth trauma and violent coughing from illnesses such as tuberculosis. Vitamin deficiencies were unlikely, the researchers noted, given that ancient Mesopotamia had ample sunlight and fresh produce due to the fertile land between the two rivers. Birth-related fractures typically heal within weeks in infants, and bone density and growth measurements for the baby matched those of its peers from that time, indicating that the child didn't have an underlying skeletal condition.

To gauge how unusual the injuries were, the team compared the infant to other children excavated from the same burial area. None of the other youngsters with substantial rib preservation showed similar fractures, making the infant's injuries an outlier in the local population.

It appears that the infant likely experienced "caregiver-induced violence," Grzegorska said. This term is used because the evidence can't identify who caused the harm or confirm intent, Grzegorska said. "We don't want to point fingers at any specific individual," she said, noting that in many ancient cultures, multiple family members, not just parents, helped raise children.

Other clues that might shed light on the infant's injuries are missing from this case, she added. Unlike modern clinicians, bioarchaeologists can't interview a living patient or bystander, or examine soft tissue that might reveal more about the abuse. The partially healed state of the fractures suggest the infant survived for some time after the injuries were inflicted, Grzegorska found — an indication that the trauma was not immediately fatal.

Around the time the infant died, Tell Brak was transforming into a city, so the authors suggested that the stresses of early urbanization and possibly less support from extended kin could have contributed to the violence. Centuries after the infant died, upheavals related to city building appear to have led to mass deaths that were likely caused by violent conflict, Grzegorska noted.

Documented cases of child abuse remain exceptionally rare in the archaeological record, with only a handful previously identified in places such as Egypt, France and Lithuania.

Archaeologists in Vietnam have made a discovery that could rewrite scientists' understanding of where syphilis originated.

The team found the Stone Age skeletons of three people who had a debilitating bacterial disease that left marks on their bones and teeth. This disease is in the same family as syphilis, and the discovery of it in prehistoric Vietnam could challenge the idea that syphilis-like diseases originated in the Americas.

In a study published March 13 in the International Journal of Osteoarchaeology, the researchers documented three cases of congenital treponematosis at two Neolithic sites in Vietnam dating to around 4,100 to 3,300 years ago. Treponemal diseases are a group of infections caused by the bacterium Treponema pallidum. These diseases, caused by different subspecies of the bacterium, include syphilis, bejel and yaws.

For decades, researchers believed that of these diseases, only syphilis could be spread through congenital transmission, meaning from parent to child during pregnancy, study first author Melandrie Vlok, a lecturer in anatomy and physiology at the Charles Sturt University, told Live Science in an email. The assumption has been used to back the claim that syphilis originated in the Americas, after previous research found that 5,500-year-old remains of children carried bacteria related to syphilis alongside signs of congenital infection, Vlok said.

But importantly, "none of this DNA is actually syphilis," she noted. This distinction matters as evidence of congenital infection by the bacteria has long been seen as evidence of syphilis itself.

"Our new research flips the script," Nicola Czaplinski, a doctoral candidate in health sciences at the University of Notre Dame Australia, said in an email to Live Science. According to their findings, "congenital transmission isn't unique to syphilis."

Three children from neolithic Vietnam

While scientists have long debated where treponemal diseases originated, only one other study had investigated the question in Vietnam.

That study included cases that dated to the early agricultural transition, around 4,000 to 3,500 years ago. It focused on Man Bac, a site dating to around 4,100 to 3,300 years ago in northern Vietnam, and found that over 10% of the buried people examined had markings on their bones and teeth consistent with treponematosis. Most of those affected were young children and adolescents.

The new study looked at 16 sites across Vietnam, including Man Bac, and examined a total of 304 individuals dating from 10,000 to 1,000 years ago. It found evidence of congenital treponematosis in three children. Two individuals, aged 18 months and 5 years old, were identified at Man Bac, and a third individual from An Son, dating between 3,900 and 3300 years ago, in southern Vietnam and was around 2.5 years old.

The children's teeth bore the most telling signs of congenital treponematosis, with some appearing stunted, malformed, or as though they were "worm-eaten."

The researchers noted that because most of the individuals with treponematosis across both studies were children and adolescents, the disease was likely not transmitted sexually. But the existence of congenital cases complicates the assumption that mother-to-child transmission was exclusive to syphilis, a cornerstone to the "Columbus hypothesis" that leans on the idea that syphilis originated in the Americas.

"This discovery challenges one of the key pillars of the 'Columbus brought syphilis [to Europe from the New World]' theory and shows that … we're still a long way from solving the mystery of where syphilis really began," Czaplinski said.

But despite this breakthrough, many challenges remain in determining exactly where syphilis originated. Vlok explained that in tropical regions like Southeast Asia, DNA doesn't preserve well.

"Recovering it often requires taking large amounts of bone, and that raises serious ethical concerns," she said. "Human remains are not just scientific samples; they are the ancestors of living communities and must be treated with care and respect." Similarly, Africa is understudied in regards to the origins of treponemal disease, she added.

Charlotte Roberts, professor emeritus of bioarchaeology at Durham University in the U.K. who wasn't involved with the new study, noted that the research adds to scientists' knowledge of this disease group.

"Treponemal disease has been studied for decades by palaeopathologists, often with controversial outcomes," Roberts told Live Science in an email. "This is, therefore, a welcome study of an area of the world which has not seen much evidence to date."

Additionally, the study suggests that early migrations of people from China may have been responsible for the spread of the disease in Vietnam. Both sites featured in the study were established as the result of early migrations of farmers into mainland Southeast Asia and their subsequent interactions with local foragers.

"Of particular interest," Roberts said, "is the suggestion that migration of people in the region may be directly linked to the occurrence of this infection."

The mysterious Roman-era burial rite of pouring liquid gypsum over the dead wasn't limited to elite adults as previously thought; it was also performed on children, including babies as young as 1 month old, researchers have found.

The finding contradicts Roman-era legal sources who wrote that infants under 12 months old were not supposed to be mourned at all, according to two blog posts published by the Seeing the Dead project, a collaboration between the University of York and the York Museums Trust. Their team is investigating the discovery of children among the rare "gypsum burials" found in York, in northern England.

Liquid-gypsum burials have long confounded researchers. The enigmatic practice involved placing the deceased in a stone or lead sarcophagus and then pouring liquid gypsum over them. The plaster-of-paris-like substance hardened over their bodies, preserving traces of high-status clothing. But new research found that even the youngest members of ancient society were mourned.

"Infants were the most vulnerable members of Roman society," Maureen Carroll, a Roman archaeologist at the University of York, wrote in a Feb. 18 blog post, particularly given the high infant mortality rate of around 30%. But even though historical records say babies younger than 1 year old were not to be mourned because infant deaths were commonplace, Carroll has found that these restrictions applied only to public mourning.

"They had no bearing on sentiments such as grief or the sense of loss felt and expressed by the surviving family in private," she wrote.

Among the more than 70 gypsum burials Carroll has studied, at least seven belonged to children, including three infants under 4 months old. The practice of liquid-gypsum burial seems to have been reserved for the Roman elite in York, and it was usually employed on adults. Infants were more often buried in large jars called amphorae; ceramic tile boxes; or small, wooden coffins.

One remarkable infant burial was found in 1892 during the construction of the York Railway. The newborn, just 1 or 2 months old, was covered with a cloak of purple-dyed wool decorated with gold thread and tassels, before being placed in a lead sarcophagus and covered in liquid gypsum.

Although nothing remains of the infant's bones today, impressions of the brilliant purple-and-gold cloak can still be seen. This is the only gypsum burial with dyed fabric ever found, Sarah Hitchens, an archaeological textile expert at the University of York, wrote in a Feb. 23 blog post.

"It is likely that the purple textile was made from an animal fibre such as wool," Hitchens wrote, and the cloak was likely draped over the infant's body as a burial shroud.

Chemists on the project team are now analyzing the hardened gypsum covering to glean more information about Romano-British burial practices.

"We are testing the gypsum casing for evidence of aromatic substances, such as frankincense or mastic," dried tree sap and resin, respectively, Carroll told Live Science in an email. They also plan to test the purple dye to determine whether it came from murex, a type of snail from which the ancient Romans extracted a natural reddish-purple dye. The gold threads will be analyzed as well, Carroll said.

Other liquid-gypsum burials found in York include a child of about 4 months old discovered wrapped between the legs of two adults. It's unclear if these three people constituted a family, "but it is evident that they were closely associated in life and in death," Carroll wrote.

In another case, a girl who was between 7 and 9 years old when she died was buried with an array of gold, silver, copper, jet, glass and coral jewelry. Two pairs of boots and a pair of sandals were discovered near her feet, and the bones of what was likely a pet chicken were found in her coffin as well.

"The 3D scan of her body visible under a shroud or sheet reveals how frail and thin she was, perhaps pointing to a protracted illness before her death," Carroll wrote.

These lavish burials of infants and children discovered in York show that Roman legal texts, which were written primarily by older men, did not reflect the reality of life and death in Roman Britain.

"It all certainly suggests that children this young were valued and cared for, unlike the age-old notion that Romans did not care when their infants died because infant mortality was high," Carroll said. "Utter nonsense!"

Roman Britain quiz: What do you know about the Empire's conquest of the British Isles?

A rare Stone Age cemetery on a Swedish island reveals that some of Europe's last hunter-gatherers were buried not with their extremely close relations but with more distantly related people, according to a new DNA analysis.

However, some burials had close biological family members, including that of a teenage girl whose father's jumbled bones had been placed on top and next to her, the researchers found.

Since the site was first excavated in 1983, Ajvide on the western Swedish island of Gotland has yielded 85 graves from the Pitted Ware culture, a hunter-gatherer society that lived in the area 5,500 years ago. Although agriculture had spread across Europe along with farming communities at this time, some hunter-gatherer groups continued to live in Scandinavia, primarily hunting seals and fishing.

Ajvide was occupied for at least four centuries, and archaeologists have found tons of pottery and animal bones, in addition to a cemetery. Excavation of the cemetery revealed that eight graves contained more than one person. Researchers originally assumed that the people in the graves were closely related. But advances in ancient DNA analysis raised the possibility of fully investigating familial relationships in the Ajvide cemetery.

"As it is unusual for these kinds of hunter-gatherer graves to be preserved, studies of kinship in archaeological hunter-gatherer cultures are scarce and typically limited in scale," Tiina Mattila, a population geneticist at Uppsala University, said in a statement. Mattila led the genetic analysis of four of the burials, and the study was published Wednesday (Feb. 18) in the journal Proceedings of the Royal Society B.

In one grave, excavators had found an adult female skeleton along with the skeletons of two young children. The researchers' DNA analysis revealed that the children were a boy and a girl who were full siblings. The woman, however, was not their mother and may have been their father's sister or their half-sister.

A second grave contained the skeletons of a boy and a girl buried together. DNA analysis showed that they were third-degree relatives – who share one-eighth of their DNA – and likely cousins. In the third grave, DNA analysis of the skeletons of a girl and a young woman revealed they were also third-degree relatives, likely cousins or a great-aunt and great-niece.

And in the fourth grave, there was a young teenage girl buried on her back in an outstretched position, with a pile of bones on top and next to her. Using DNA analysis, the researchers discovered that the bones were those of the girl's father. His death probably predates hers, and his bones had likely been dug up and moved to his daughter's grave from elsewhere, the researchers said.

"Surprisingly enough, the analysis showed that many of those who were buried together were second- or third-degree relatives, rather than first-degree relatives — in other words, parent and child or siblings — as is often assumed," study co-author Helena Malmström, an archaeogeneticist at Uppsala University, said in the statement. "This suggests that these people had a good knowledge of their family lineages and that relationships beyond the immediate family played an important role."

This study of the Ajvide burials is the first to explore family relationships among Scandinavian Neolithic hunter-gatherers, according to the statement. But more work is planned, as the researchers will now analyze all the skeletons recovered from the cemetery to learn more about ancient hunter-gatherer social structure, life history and burial rites.

Stone Age quiz: What do you know about the Paleolithic, Mesolithic and Neolithic?

The famous Inca "ice mummies" have been holding secrets since their discovery decades ago, and CT scans are now revealing what these children's last moments were like, a new study finds.

The researchers examined the remains of four Inca children who were killed about 500 years ago and left on remote peaks in the Andes as "messengers to the gods," the researchers wrote in the study. However, the new CT scans revealed that at least one of these children had been killed elsewhere and then relocated to a mountain peak, according to the study, which was published in the April issue of the Journal of Archaeological Science: Reports.

The research also showed that some of the children selected for this ritual "capacocha" sacrifice had injuries and diseases when they were killed, contrary to some early Spanish accounts that the victims were always in perfect health.

"Our findings show that chroniclers' accounts should be treated with caution," Dagmara Socha, an archaeologist at the University of Warsaw in Poland and the lead author of the study, told Live Science. "Although historical sources describe the children as physically perfect and without flaws, modern scientific analyses reveal a very different reality."

The four mummies are those of an 8-year-old girl, a 10-year-old girl, a 14-year-old girl, and the famed "Lady of Ampato" — also known as the "Ice Maiden" and "Momia Juanita" — who was also sacrificed when she was about 14 years old. Her mummified body was found in a shrine near the summit of Peru's volcanic Mount Ampato in 1995.

The researchers determined that the 10-year-old girl found near the same summit had been sacrificed elsewhere. The scans revealed that the organs in her abdomen and chest cavities had been removed and replaced with stones and textiles before the body was wrapped and placed in a sitting position, with the knees drawn up to the chin, on a plateau near the top of the mountain.

Although the ice mummies were preserved by the extremely dry air at the altitudes where they were found — about 19,000 feet (5,800 meters) above sea level — the 10-year-old girl's missing organs are the first evidence that any of the bodies had been deliberately prepared for mummification, possibly to remedy what were seen as the victims' physical deficiencies, the researchers wrote.

Ice mummies

The medical scans of the four mummies — three from Mount Ampato and another from a shrine near the summit of the Sara Sara volcano, about 100 miles (160 kilometers) roughly west — showed some of the young sacrificial victims had suffered from several ailments.

Scans of the 8-year-old girl's mummy found on Mount Ampato revealed an enlarged esophagus that may have been a symptom of Chagas disease (a parasitic infection common in the region) and scars in her lungs that may have been caused by tuberculosis.

These health conditions were likely common in the Inca population at the time, so it's no surprise that the mummies weren't "perfect" as the European accounts had claimed. "This may reflect the general living conditions within the Inca Empire, but it may also indicate that European chroniclers did not fully understand what the Incas themselves considered ideal," Socha said.

Divine messengers

According to some early Spanish writers in Peru, the capacocha sacrifices were among the most important rituals in the Inca world. In these sacrifices, children or young teens — both boys and girls — would be ritually killed, and their bodies would be naturally mummified near the tops of high mountains so they would act as "messengers to the gods."

The methods of killing differed; some victims were strangled, while others were smothered. Socha said it seemed that each of the four sacrificial victims in the study had been killed by a severe blow to the head, possibly from a wooden club.

Early Spanish accounts indicated that the young victims of the capacocha rituals acted as "messengers" for a long time after they had been ritually killed. For example, a report by the conquistador Pedro Pizarro (a young cousin of Francisco Pizarro) stated that living people visited ice mummies to seek approvals for marriages.

"The evidence suggests that these children … continued to function as mediators between the living community and the divine Apus [Andean deities] long after their deaths," Socha said.

We've all seen it: a kid with one finger wedged up a nostril, mining the cavity for a golden nugget, teasing it out, and then gobbling it like a tasty snack. It may be gross to adults, but most children seem completely unfazed. So why do kids eat their boogers, and are they possibly onto something?

Most parents will tell you how common it is for children to eat their own mucus — a behavior known as "mucophagy" — yet data on its prevalence are scarce.

One survey suggests that nose picking overall isn't limited to kids; adults commonly do it, too. Another 2001 study based on a survey of 200 teenagers in India found that almost all participants admitted to picking their noses; what's more, nine in the sample said they routinely ate the boogers. As for the question of why kids eat their own mucus, there haven't been any rigorous investigations.

However, researchers have found that mucophagy is shared by at least 12 other primate species.

Evolutionary biologist Anne-Claire Fabre first discovered this when watching the aye-aye (Daubentonia madagascariensis). This lemur species is known for its 3-inch-long (8 centimeters) middle finger, which it uses to pry insects out of hard-to-reach crevices. But when Fabre was watching a captive aye-aye in 2015, she was surprised to see it sticking that long, thin digit into its nostrils; extracting mucus; and then licking its finger clean.

"It was hilarious and disgusting at the same time," recalled Fabre, an associate professor at the University of Bern in Switzerland. "It seemed that it was really enjoying what it was doing. It's something that they do pretty often." (It's possible that the captive aye-aye was unusual in its nose-picking habit, but there's no reason to assume this doesn't also happen in wild aye-ayes, Fabre said.)

This made Fabre wonder if other primates eat their mucus, too. When she carried out a literature review that included her own observations of the aye-aye, she found evidence that gorillas, bonobos, chimpanzees, macaques, capuchins and other primates also pick their noses and eat the mucus. Most species used their fingers, but some used sticks to pry out the spoils. Some primates even extended the favor, picking others' noses too, the research found.

"When you see the composition of mucus, it's mostly water, at more than 98%," Fabre said. The remainder is composed of a protein-carbohydrate ingredient called mucins, and salts. It's possible that animals reap some benefit from consuming these ingredients, the way that some species will eat their own feces to digest the remaining nutrients there, Fabre explained.

This idea raises the question of whether there may be a deeper evolutionary basis for mucophagy in humans.

Mucus creates a protective layer that traps dust, spores and disease-causing microorganisms as we inhale, before it reaches the lungs. In 2013, a biochemist shared a hypothesis that eating boogers could therefore expose children to small doses of pathogens that train the immune system to identify these molecules and can help to trigger an immune response. However, this idea was not ultimately tested in empirical research.

Dr. Chittaranjan Andrade, author of the 2001 nose-picking study in teenagers, is wary about such theories. "I am skeptical. Any immune substance that survives drying in the mucus is likely to be very small in quantity, and it is also likely to be digested after ingestion," therefore likely having a limited effect, the senior professor emeritus at the National Institute of Mental Health and Neurosciences in Bangalore, India, explained in an email.

Other experts have cautioned that because nasal mucus can spread pneumonia-causing bacteria, nose picking and mucophagy in children should be controlled when they are around immunocompromised people.

With no evidence behind the idea that mucophagy boosts immunity, researchers have looked for more intuitive reasons why kids eat their own mucus. Boogers can create itching, tightness, and discomfort in the nose that might prompt nose-picking, and curious children might then give it a taste-test, Fabre suspects.

One researcher asked children directly why they ate their boogers. The results were published in a 2009 book chapter that was not peer-reviewed and were based on a very small sample of just 10 children. But their insights included the fact that they liked eating boogers simply because of their appealing texture and taste.

Andrade believes that children develop this habit because it doesn't yet have the negative association that it carries for older people. "Because [children] do it openly, they are observed and scolded, and because the act, picking as well as eating, is stigmatized, my guess is that they do not repeat it, not openly anyway," Andrade said.

Until there's concrete research into the question, the answer to precisely why children eat their boogers will remain elusive. To Fabre at least, it's a topic that deserves more investigation to understand if there are possible benefits or harms of mucophagy to child development.

Ultimately, she takes kids at their word and believes that they may eat their boogers simply because they like it. "It's something that is crunchy and a little bit salty," she says. And having watched nose-picking aye-ayes for hours and learned about the prevalence of this habit in other species, it no longer gives Fabre the ick: "Honestly, in my opinion, it's not something that is disgusting."

The tree canopy is shrinking across thousands of California schoolyards, which may leave children more vulnerable to the harmful effects of extreme heat, according to a recent study.

In the research, published in the journal Urban Forestry & Urban Greening, scientists looked at snapshots of more than 7,000 public schools in urban areas across the Golden State. The analysis included schoolyards and the areas immediately surrounding them. One image, taken in 2018, provided baseline information about each school's existing tree canopy. The next, taken in 2022, showed whether that canopy had increased, decreased or stayed stable.

Across the schools evaluated, the majority saw some amount of tree-canopy decline between the two time points. "A major important takeaway is that across the state, most schools (85%) experienced tree canopy loss during the study period," Dr. Lindsey Burghardt, chief science officer for the Center on the Developing Child at Harvard University, who was not involved in the work, told Live Science in an email.

Some schools lost more than 40% of their canopy cover over the four-year period, according to the report. This percentage change was relative to each school's baseline tree cover, so these declines were "even more concerning" to see in areas that had poor canopy cover to begin with, the authors wrote.

Past research had already shown that tree cover on California's school campuses tends to be lower than the average canopy cover across the cities in which they're situated. "The urban tree canopy cover in California is pretty low, but in school grounds, it's even lower than the average, on the city level," study co-author Alessandro Ossola, an associate professor in the Department of Plant Sciences at the University of California, Davis (UC Davis), told Live Science.

Given the amount of time children spend at school, these campuses are an important venue for kids to exercise and play outdoors, the authors argue, and Burghardt agrees.

"The existing literature confirms that increasing temperatures in schools affect children's ability to learn and play, and this can affect their physical and mental health in childhood and beyond," she said. "Young children's bodies heat up more quickly than ours, and they are less able to cool themselves by sweating." This overheating can affect multiple bodily systems, undermining cognitive function and concentration, activating the body's stress response, and driving dehydration that can injure organs, particularly in children with existing chronic conditions.

But as average temperatures rise due to climate change, droughts and extreme heat events are expected to become more frequent, prolonged and severe across California. In urban centers, those effects can be amplified in "heat islands," where buildings and roads emit more heat than would landscapes with more natural features, like trees and bodies of water.

"The impact is exacerbated because there's so much built infrastructure that actually accumulates the energy and then radiates it out again," said study co-author Luisa Velásquez Camacho, a postdoctoral scholar at UC Davis. Trees cool their surroundings, both by providing shade and by releasing water into the air from their leaves, she told Live Science.

"A tree is like an air conditioning unit because it's actually providing evaporative cooling," Ossola said. By comparison, artificial shade structures, which are notably expensive to install, can end up radiating heat across a playground rather than cooling the air as a tree would, he said.

"It's [like] the broiling function in the oven, when it comes from the top," added study co-author Moreen Willaredt, another UC Davis postdoc.

In summary, trees can be powerful mitigators of heat, so the researchers wanted to take stock of the state of trees located around California schools. The dataset they used enabled them to examine changes in the trees' canopies with a "fine degree of resolution," Burghardt said.

Areas of canopy loss were dispersed across the state, but there were pronounced clusters in the Central Valley and certain parts of Southern California. Hard-hit counties included Tulare, Fresno and San Bernardino, which generally had relatively poor canopy cover at baseline. In the Central Valley, the study authors suspect that prolonged drought conditions and frequent extreme heat events may have contributed to this decline, but their study wasn't designed to pinpoint the exact drivers of the trend.

About 15% of the schools included in the study saw their tree canopies increase, generally by more than 20%, "highlighting areas of remarkable canopy recovery or growth," the authors wrote. Imperial County and San Joaquin County stood out as having marked increases, and some pockets of growth were also spotted in the Central Valley, suggesting that there's a "mosaic" of trends across that region.

The study authors hope their work informs future greening initiatives to help create and restore canopy cover at schools. "What we are trying to do is to essentially see where the gaps are, and [find] opportunities to prioritize the limited amount of trees going into the ground," Ossola said.

"I agree that this is an important next step," Burghardt said. "All children deserve to learn and play in an environment that supports their healthy development, and access to safe greenspace is a key element of a healthy developmental environment."

Marks on 4,000-year-old skeletons reveal that Bronze Age women in Nubia were carrying goods and young children on their heads using tumplines, a type of head strap that can hold a basket, a new study finds. The discovery reveals the oldest known use of head straps in the world.

Researchers made the finding in Sudan after analzying the remains of 30 people (14 females and 16 males) buried in a Nubian Bronze Age cemetery. One, an elite woman who was around 50 years old when she died, had the clearest marks indicative of head straps.

This is the "first clear evidence that women were using head straps — tumplines — to carry loads as early as the Bronze Age," study lead author Jared Carballo-Pérez, a researcher of bioarchaeology at the Autonomous University of Barcelona, told Live Science in an email.

Carballo-Pérez and his colleagues investigated at the archaeological site of Abu Fatima which consists of a cemetery that is located by the third cataract of the Nile River, in what was once the ancient kingdom of Kush.

After analyzing the 30 people in the Abu Fatima cemetery, the team found that women tended to have more wear on their head and neck areas than the male skeletons did, indicating that the women were bearing loads with head straps.

"Women exhibited specific degenerative changes in the cervical vertebrae and skull areas associated with prolonged use of tumplines that transfer weight from the forehead to the upper back," the team wrote in a statement.

Related: 3,500-year-old burial of Nubian woman reveals 1 of world's earliest known cases of rheumatoid arthritis

The cemetery was only about 6 miles (10 kilometers) north of Kerma, the capital city of Kush. "The capital in Kerma was a densely populated urban center that featured various facilities such as storage buildings, ritual structures, breweries, bakeries, and defensive walls," the researchers wrote in the study, which was published in the March issue of the Journal of Anthropological Archaeology.

Based on the skeletal analyses from the cemetery, it's likely that women in Kerma and the surrounding area carried goods and young children using head straps, the new research suggests.

The team also analyzed ancient art from Egypt that depicts Nubians who lived around this time. They noticed that some of the Nubians featured appear to be carrying children using head straps.

"The forehead straps would be attached to the basket and placed over the top of the head. This is supported by various depictions of Nubian women found in tribute scenes from 18th Dynasty Theban tombs," the team wrote in the paper.

Woman buried with ostrich fan

The elite woman's remains showed the "clearest signs" of head strap use, the team wrote in the statement. She lived sometime between 2600 and 2000 B.C., study co-author Sarah Schrader, an associate professor of archaeology at Leiden University in the Netherlands who co-led excavations at Abu Fatima, told Live Science in an email. Her remains were buried with an ostrich feather fan and a leather pillow.

The elite woman's identity is unknown, but the luxury items buried with her suggest that she had a different status to others in her community, Schrader said. It's unclear exactly what her status was, but the signs of wear indicate she still had to carry heavy loads on her head. Additionally, isotopic analysis of her remains suggests that she is from outside the region, possibly the second cataract of the Nile. This is north of the cemetery but still within the kingdom of Kush.

People in modern times still use tumplines. The practice is "still alive today in rural regions of Africa, Asia, and Latin America," the team wrote in the statement.

Roughly 1 in 8 child flu deaths in the U.S. so far this year have been linked to brain damage, according to a report released by the Centers for Disease Control and Prevention (CDC).

The U.S. is experiencing its most severe flu season in more than a decade, Live Science previously reported. More than 19,000 people have died including 68 children, at least nine of whom had flu-associated brain complications, according to a CDC Morbidity and Mortality Weekly Report published on Feb. 27.

In January, the CDC received anecdotal reports of children becoming critically ill and dying with influenza-associated encephalopathy or encephalitis (IAE), a spectrum of neurological syndromes. Encephalopathy is a group of conditions that cause brain dysfunction while encephalitis causes brain swelling, according to the Cleveland Clinic. IAE symptoms include seizures, decreased level of consciousness, hallucinations and personality changes lasting more than 24 hours, according to the report.

The CDC doesn't normally track cases of IAE, so it's not clear whether the number of cases reported this season is higher than in previous years. However, they did warn doctors to be on the lookout for IAE.

"It is not known whether cases observed in the 2024–25 season vary from expected numbers," the CDC report authors wrote. "Clinicians should consider IAE in children with influenza and abnormal neurologic signs or symptoms."

Related: How do people die of the flu?

Flu is among the deadliest viruses in the world. While it kills around 1.8 people per 100,000 infections, flu infects enough people that thousands die from it every year in the U.S. Nervous system injury, including IAE, is one of the main causes of flu fatalities among children, according to a 2021 study published in the journal Medical Science Monitor.

To investigate anecdotal reports of IAE, the CDC contacted state health departments for data on influenza-associated deaths in children across flu seasons between 2010 and 2025. Flu can spread all year round, but there are more cases in the fall and winter (the flu season), with activity peaking between December and February, according to the CDC.

The CDC found that as of Feb. 8 in the 2024-2025 season, 68 children had died with flu, with IAE documented in nine (13%) of those cases. That compares to a rate of 9% across all years, but it varied season to season and peaked at 14% in the 2011-2012 season, according to the report.

While the CDC couldn't identify whether the current rate of IAE was abnormal, the report highlighted the importance of vaccination and recommended flu shots for all eligible people aged 6 months or older so long as influenza viruses are circulating.

"Influenza vaccination is an important tool for preventing influenza and its associated complications," the report authors wrote.

Flu vaccine uncertainty

Early data suggest that this year's flu shots have dramatically reduced seasonal flu hospitalizations. However, uncertainty hangs over the next vaccination round for the 2025-2026 season.

Flu mutates quickly. So every year, manufacturers use strains circulating in the Southern Hemisphere to predict the strains most likely to circulate in the coming season and create updated versions of the flu vaccine targeted to those strains. A U.S. Food and Drug Administration (FDA) advisory panel normally meets around this time of year to decide which strains should be included in the vaccines for the next season. That meeting was scheduled for Mar. 13 but was canceled without reason, Reuters reported on Feb. 28.

There is concern among experts that the cancellation could disrupt the production of flu vaccines, which could mean higher rates of serious illness and death, Live Science previously reported.

An FDA spokesperson told Reuters on Feb. 28 that it would make recommendations to manufacturers public in time for updated vaccines to be available for the 2025-2026 season.

This is the second time a vaccine advisory panel has been disrupted since Robert F. Kennedy Jr. took over as head of the U.S. Department of Health and Human Services, Reuters reported. Kennedy Jr. is a notable vaccine skeptic, though he's denied being anti-vaccine.

This article is for informational purposes only and is not meant to offer medical advice.

Some parents insist that they could never pick a favorite child — but a new study calls that into question.

A new analysis of 30 studies that collectively included almost 20,000 people revealed that parents are more likely to favor their daughters over their sons. The research also suggests that parents favored children who are perceived to be more agreeable and conscientious than their siblings. The studies included in the analysis were conducted only in North America and Western Europe, and they included predominantly white people, meaning that the results may not be applicable to people from other demographics.

In this context, favoring a child doesn't necessarily mean that parents have "favorites" — rather, they choose to treat certain children in a more favorable way than their siblings, the researchers noted in the study, which was published Jan. 16 in the journal Psychological Bulletin.

"It isn't about the parents loving one child and hating the other," said study co-author Alexander Jensen, an associate professor in the School of Family Life at Brigham Young University in Utah. "It's about being more affectionate with one of them, having more conflict with one of them, or spending more time with one of them," he told Live Science in an email.

Related: Middle children are more agreeable, humble and honest than siblings, new study suggests. The baby of the family would like a word.

It is important to understand these different parent-child interactions because children who receive more favorable treatment from their parents are more likely to have better mental health, increased academic success and healthier family relationships, among other benefits, previous research has shown. The opposite is true for children who receive less favorable treatment.

"A study several years ago suggested that if children understand why they are treated differently, then the differences don't matter," Jensen said. In other words, if a child sees that their treatment is justified, they may be more likely to accept it. For example, an older child may feel left out if their mom spends more time helping their younger sibling with their homework, until they realize that their sibling needs extra help with it.

"I hope parents will use our study as a catalyst to consider how they may treat their children differently, then work to make sure those differences are fair and understood by their children," Jensen said.

In the new analysis, Jensen and colleagues looked at data from 30 scientific papers and 14 databases, which chronicled information on the family dynamics of 19,469 people. Around 67% of these individuals were from the U.S., while the rest were from Western Europe and Canada.

The researchers investigated how specific characteristics of a child correlated with how their parents treated them. This data had been collected in a variety of ways, including via interviews, surveys and at-home observations.

The children's characteristics included factors such as when they were born relative to their siblings, their gender, and their temperament and personality traits, such as extraversion, agreeableness, conscientiousness and neuroticism — the tendency to experience negative emotions. Parents' preferential treatment was measured by how parents interacted with their children, how much money they spent on them or how much control they wielded over them, in regards to having strict or lenient rules.

The study only looked at correlations between child characteristics and differential parental treatment. Therefore, the findings alone cannot explain why parents seem to favor daughters and more-agreeable children over sons and less-aggreeable children, respectively.

That said, agreeable children are likely to be more willing to do what they're asked, meaning that their parents may find it easier to manage them and thus respond more positively towards them, the study authors speculated.

In the future, more research is needed to understand whether these parental preferences also exist in families from a more diverse range of cultures, as well as across different stages of life — for instance, looking at parents' treatment of their kids in adulthood, too.

Disease name: Angelman syndrome

Affected populations: The disorder is believed to affect somewhere between 1 in 12,000 and 1 in 24,000 people, although these figures may be underestimated. Many cases of Angelman syndrome can go undiagnosed because the disorder shares symptoms and characteristics with other conditions. Men and women are equally likely to experience the disorder.

Causes: Angelman syndrome is a genetic disorder named after Dr. Harry Angelman, who first reported it in 1965. The disorder principally affects the central nervous system, meaning the brain and spinal cord, and it's caused by mutations in the UBE3A gene. This gene carries instructions for a protein needed to maintain the normal development and function of cells, including neurons in the brain.

In each cell, humans typically have 23 pairs of chromosomes — thread-like structures that house DNA. One parent contributes half of each chromosome pair, and the other parent contributes the other half. UBE3A is located on chromosome 15. Mutations that delete the gene or change its structure, function or activity can cause Angelman syndrome. In many cases, a mutation develops spontaneously on the copy of the gene from the mother.

The genetic mutations behind Angelman syndrome usually occur randomly, but between 3% and 5% of children inherit them from their parents. In around 10% of people with the condition, the exact cause of the syndrome can't be identified.

Related: New genetic cause of intellectual disability potentially uncovered in 'junk DNA'

Symptoms: People with Angelman syndrome normally start to develop symptoms of the disorder in early childhood. These include developmental problems, such as having difficulty sitting unsupported or babbling, that become apparent around ages 6 to 12 months.

As the disorder progresses, affected people may struggle to speak and walk because of balance and coordination issues. They may also experience seizures, which usually begin when a child is between 2 and 3 years old. Furthermore, some people with the condition may have distinctive facial features, such as a prominent chin, deep-set eyes or abnormally wide mouth. People who have the syndrome usually have a normal life expectancy.

Symptoms of Angelman syndrome can sometimes be confused with other disorders that also cause developmental delays, such as autism or cerebral palsy, possibly leading to misdiagnosis.

Treatments: There is currently no cure for Angelman syndrome.

However, several treatment options exist to help manage their symptoms. For example, doctors may prescribe anti-epileptic drugs to control patients' seizures. Physiotherapy and communication therapy can also help to respectively improve patients' ability to walk and communicate with others without speaking — by using hand gestures or signs, for example.

This article is for informational purposes only and is not meant to offer medical advice.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Natural selection is happening among humans right now — high up in the mountains of Nepal, scientists have discovered.

The new research suggests that, compared to their peers, ethnic Tibetan women who are physiologically better adapted to living in the low-oxygen conditions at high altitudes bear more children. This hints that these beneficial traits are currently being "selected for," meaning there's an evolutionary pressure to pass them on to the next generation.

In other words, natural selection is occurring.

The researchers revealed their findings in a study published Oct. 21 in the journal PNAS. The study looked at more than 400 women, ages 46 to 86, who live in villages located in the Upper Mustang District of Nepal on the border with Tibet. The villages sit 11,500 to 13,500 feet (3,500 to 4,100 meters) above sea level.

People who live at high altitudes face harsh environmental conditions, including low air pressure that reduces the amount of oxygen available in the body. These low oxygen levels can cause tissues to stop functioning, leading to symptoms such as confusion and difficulty breathing. In more severe cases of this condition, called hypoxia, people can develop deadly illnesses like acute mountain sickness or high-altitude cerebral edema, in which the brain swells.

Related: Gene mutation helps Andean highlanders thrive at altitude, and 'living fossil' fish live deep underwater

Low-oxygen environments are especially challenging for pregnant women at higher altitudes, due to a heightened risk of preeclampsia, a potentially fatal blood-pressure condition, and are more likely to give birth to babies with low birth weights. Therefore, in populations living at high altitudes, there may be strong selective pressures for traits that help increase survival, both during and after pregnancy.

Previous research has shown that Tibetans have physiological traits and versions of genes that help them to survive in low-oxygen environments more easily than people without these characteristics. In the new study, researchers wanted to see if they could link these genetic and physiological traits with reproductive success to show that evolution is happening via natural selection in these populations.

In biology, "reproductive success" is typically measured through a tally of how many offspring an organism has produced, because that reflects the number of times they've passed on their genes. So the researchers recorded how many children the women in these villages had given birth to. They also took various physiological measurements and analyzed the women's DNA.

They found that the women who bore the most children carried typical levels of hemoglobin — the blood responsible for transporting oxygen. But their hemoglobin was capable of carrying more oxygen than women who had fewer children.

Furthermore, the women with more children had greater blood flow to their lungs. And their left ventricles — the chamber of the heart that pumps oxygenated blood to the body — were wider than those with fewer children. A wider ventricle means more oxygen-rich blood can get to a person's tissues in a given heartbeat.

In a separate analysis, the researchers found that around 80% of the women in the study carried a version of a gene known as EPAS1, which is thought to lower hemoglobin concentrations in the blood. This may seem counterintuitive as having less hemoglobin means you can't carry as much oxygen in the blood. However, too much hemoglobin can thicken the blood, making people vulnerable to developing a condition known as chronic mountain sickness.

The fact that the EPAS1 variant is so common suggests there is a lot of pressure for this version of the gene to be passed on from one generation to the next.

These new findings shed light on how evolution and adaptation occurs in humans, study co-author Cynthia Beall, a professor emerita of anthropology at Case Western Reserve University in Ohio, told Live Science. The findings may also have applications in medicine — for instance, they could potentially provide insight into diseases that are associated with low oxygen levels, such as asthma and other lung conditions, she suggested.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Scientists have discovered the trigger that makes inflammation spiral out of control for some children after a COVID-19 infection.

It turns out, the immune system mistakes a protein made in most parts of the body as foreign because it mimics one that forms part of SARS-CoV-2, the virus that causes COVID-19.

The condition, called multisystem inflammatory syndrome in children (MIS-C), was first identified early in the pandemic in a small percentage of children who recovered from COVID-19.

Many of these children were initially asymptomatic during a bout with the viral infection but, two to six weeks later, had life-threatening, runaway inflammation in the heart, brain, skin, blood or digestive system.

Related: Rare clotting effect of early COVID shots finally explained

MIS-C always comes with a fever, but it can also cause weakness, dizziness, stomach pain or rash.

Until recently, scientists weren't sure exactly how COVID-19 and MIS-C were linked or why the immune system might turn on the body after an infection. To understand what drives inflammation in MIS-C, researchers profiled the immune systems of 199 children with MIS-C and 45 who recovered without developing the condition.

The study, published Aug. 7 in the journal Nature, revealed 30 autoantibodies — antibodies that target a person's own body instead of a foreign invader — that were present in patients with MIS-C but not in those without the condition.

The autoantibodies with the strongest profile targeted a protein called SNX8, which is found in almost every part of the body because of its role in sorting and transporting molecules within cells.

It turned out that part of the coronavirus' "nucleocapsid protein" closely resembles the part of SNX8 that's targeted by these autoantibodies. The nucleocapsid protein is part of the virus' outer shell, which encases its genetic material. This similarity raised the possibility that, in some patients, the immune system was mistaking SNX8 for its SARS-CoV-2 lookalike and, therefore, was attacking tissues that expressed it.

To buttress this theory, the team studied T cells, which recognize and kill virus-infected cells in the body, from patients with and without MIS-C. Only T cells from MIS-C patients reacted to both SARS-CoV-2 and SNX8, supporting the mistaken-identity hypothesis. The discovery may offer new approaches to diagnosing the condition going forward.

However, SNX8 is unlikely to be the whole story behind MIS-C.

"We believe a number of rare factors come together to allow someone to get MIS-C," senior author Joseph DeRisi, a professor of biochemistry and biophysics at the University of California, San Francisco (UCSF), told Live Science. "Antibodies are one part of that but not the only part."

Either way, MIS-C is much less of a problem than it once was.

"The fascinating thing is that MIS-C has largely vanished, except in children who are unvaccinated or whose vaccines have waned," said Dr. Aaron Bodansky, study first author and a pediatric critical care fellow at UCSF. "If you predispose the immune system [to SARS-CoV-2] by vaccinating, it won't have as much time to develop this unusual response."

However, declining vaccination rates with new, updated COVID-19 vaccines may signal trouble ahead. "I think that's a serious concern," DeRisi said. "If that trend goes up, I expect we would see MIS-C increase."

For now, they aim to use their study as a model to understand other autoimmune or inflammatory conditions that may be triggered by viral infections, like diabetes or multiple sclerosis.

This article is for informational purposes only and is not meant to offer medical advice.

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The COVID-19 pandemic drastically reduced people's in-person interactions with others as events were canceled and people limited their excursions, and many also practiced social distancing and masked up if they did go out. These moves were intended to control the spread of the disease and were shown to help flatten the curve.  

However, some concerns have been raised about the potential impact of these actions on children's immune systems, and namely, kids' ability to fight infections. But did COVID "lockdowns" and other pandemic-related restrictions actually stunt kids' immune systems? 

On that front, parents should not fear, experts told Live Science. Social distancing did not permanently stunt children's immune systems. Rather, it just delayed young children's exposure to various germs.

"During the COVID lockdown, our children were exposed to far fewer pathogens than they typically are in a normal year," Dr. Sarah Nicholas, an assistant professor of pediatrics-allergy and immunology at Baylor College of Medicine in Texas, told Live Science. 

Related: Master regulator of inflammation found — and it's in the brain stem

Examples of common respiratory viruses that children may be exposed to include respiratory syncytial virus (RSV); the flu, or influenza; and human metapneumovirus, as well as various viruses that cause the common cold. After such an infection, the body builds up its immune defenses so that it can tackle these pathogens if it encounters the same ones again. 

Social distancing reduced not only the spread of COVID-19 but also that of other respiratory viruses, which tend to spread in similar ways. When these restrictions were lifted, the viruses were free to circulate in the population again. In addition, viruses responsible for causing other types of disease, such as viral gastroenteritis or stomach flu, also began spreading again. 

As social distancing behavior waned, toddlers who had never caught these viruses were suddenly playing "catch-up" with their immune systems, Dr. James Antoon, an assistant professor of pediatrics at Monroe Carell Jr. Children's Hospital at Vanderbilt in Tennessee, told Live Science. Consequently, many children became sick at the same time, leading to a surge in hospitalizations, he said. 

In the spring and summer of 2021, there was an unusual surge in RSV cases in the U.S.; the virus's transmission normally peaks in the winter. There was also a particularly large spike in cases of RSV between 2022 and 2023 that inundated many hospitals in the country. 

Although this resurgence was notable, several studies suggest that the severity of children's illnesses did not rise as COVID-19 restrictions relaxed. In other words, although case numbers rose, on a whole, children were no less able to combat these infections than kids their age had been before the pandemic. 

And while social distancing reduced children's exposure to germs, most children likely still underwent routine vaccination regimens during the pandemic, Dr. Janko Nikolich, a professor of immunobiology at the University of Arizona, told Live Science. These vaccines help prime children's immune systems against many major pathogens that are harmful to their age group. Thus, their immunity would be ready for action as social distancing eased. 

Notably, though, there was a dip in children's routine vaccinations during the pandemic, and many are still catching up to this day. 

"We know that with COVID and with flu that vaccination is absolutely the best way to prevent poor outcomes, hospitalization and complications from these viruses," Antoon said. "So if your child is eligible for some of these vaccines, it's advantageous to get them."

Parents should know that children's immune systems are generally robust, regardless of whether they lived through pandemic lockdowns, Dr. Dean Blumberg, chief of the Division of Pediatric Infectious Diseases at UC Davis Health, told Live Science. "The difference is that there were atypical patterns of exposure and infection" during and immediately after the pandemic, he said. 

"We're hopeful that kids are caught up now and going forward we shouldn't see these atypical patterns of infection," he said. 

Importantly, the pandemic highlighted the impact that basic public health measures can have in preventing the spread of harmful viruses, Antoon said. In daily practice, such measures can include staying home, social distancing and masking when you're sick. 

"Those are measures that are really easy to do and we can continue moving forward in a reasonable way," he said. 

This article is for informational purposes only and is not meant to offer medical advice.

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Many elementary-age children think artificial intelligence (AI) assistants like Alexa and Siri may have feelings or the ability to make decisions independently, a study suggests.

The research, published in the journal Computers and Education: Artificial Intelligence, investigated how 6- to 11-year-old children perceive household AI assistants, such as Alexa, Siri and Google Assistant. The study, conducted in Scotland through questionnaires and interviews, hints that children may overestimate and misunderstand the intelligence of these popular technologies.

"Children should be taught AI literacy in schools, and technology designers should take care that their AI products don't mislead children into thinking they are human-like," study co-author Judy Robertson, chair in digital learning at the University of Edinburgh, said in a statement. "AI is often designed to appear more human and intelligent than it really is, which is very confusing for children."

Of the 166 children surveyed for the study, 93% had a smart speaker at home. They reported using the devices to listen to music, ask questions, search for information, get help with homework, and listen to jokes and stories. Research by Statista, a data-analysis firm, estimates that 57% of U.S. households will own at least one smart home device by 2025, suggesting around 40 million children could have one in their house in the next year.

Related: Scientists create AI models that can talk to each other and pass on skills with limited human input

Despite their familiarity with these devices — or perhaps because of it — many of the surveyed children reported being uncertain about whether the gadgets possess human-like qualities, such as emotions or decision-making abilities. Just under one-third believed smart speakers could think for themselves, to some extent, while 40% thought they "maybe" could.

Notably, only 1% of the children actually categorized the devices as "human." Around 80% classified them as "AI," and 15% said they were "objects." But given that roughly two-thirds believed the systems might be able to think as we do, the researchers said the study highlights the risk of children overestimating the reliability and capabilities of AI systems.

Many children interviewed said that, if their Alexa breaks, it wouldn't be right to throw the device away, although this view was more common among younger participants. About 68% of the 8-year-olds in the study held this view, compared to 37% of 11-year-olds. But when asked if Alexa would feel left out if not included in a conversation, older children were more likely to say yes — 73% of 11-year-olds and 72% of 10-year-olds felt this way, while only 38% of 8-year-olds did.

"The findings reveal the importance of enhancing children's awareness and understanding of AI-supported technology to ensure safe and responsible interactions with smart technologies," study co-author Valentina Andries, who conducted the study at the University of Edinburgh but recently moved to the University of Oxford, said in the statement.

"This is becoming increasingly important in the current context of generative AI technology for various purposes, including in education," Andries added. Generative AI refers to deep-learning algorithms that generate new content, as ChatGPT generates text, for example.

Due to the rapid development and increasing availability of AI-related tech, everyone — not just young children — should try to recognize the limitations and capabilities of contraptions like smart devices, Madeline Reinecke, a postdoctoral researcher in the psychiatry department at the University of Oxford, and who was not involved in the study, told Live Science.

"I think it's important for all users, whether they're aged 5 or 50, to have an accurate picture of what these technologies are, and how they can best use them safely and responsibly," particularly as they're becoming more human-like, she said.

Reinecke suggests that additional studies into how both adults and children use and respond to such technology are needed. "There hasn't been much time for researchers to track what downstream impact they [emerging technologies] might have on children's cognitive and social development," she said.

However, regarding the University of Edinburgh's study, Reinecke noted that the children's overestimations of smart technology are likely "relatively harmless in the grand scheme" of their cognitive development.

On one hand, "smart speakers … offer an opportunity for children to learn more about the world around them," she said. "But it's imperative that they learn to think critically about where that information comes from."

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Doctors could use distinct patterns of gene activity in the blood to more quickly diagnose and treat children with life-threatening appendicitis, new research suggests. 

These genetic measures could help doctors differentiate between so-called simple and complicated appendicitis at early stages of the disease, researchers wrote in a paper published Monday (Feb. 19) in the journal JAMA Pediatrics. This method of diagnosis could flag which patients should be rushed into surgery and which might be able to be treated through nonsurgical methods, such as antibiotics, they noted.

The appendix is a finger-like tube that extends from the large intestine. If the appendix becomes blocked — for example, by food or feces — disease-causing pathogens can get trapped within it, triggering inflammation. The appendix can then swell and push against nearby blood vessels, reducing blood supply to the organ and causing sharp abdominal pain. 

There are several forms of appendicitis. One is chronic, with milder symptom flare-ups that come and go over weeks, months or years. Another is "acute," involving symptoms that suddenly emerge over 12 to 24 hours and can be life-threatening, requiring immediate surgical removal of the appendix. 

Related: What if humans didn't have an appendix?

One life-threatening complication of appendicitis is that the appendix can burst due to the pressure caused by swelling; this is known as "perforated" or "ruptured" appendicitis. In this scenario, infected fluid can leak into the abdomen and throughout the body, potentially causing blood poisoning or sepsis. If the appendix doesn't burst or develop other complications, patients are described as having "simple appendicitis," which usually requires shorter hospital stays and has a reduced risk of readmission. And in some cases, simple appendicitis can be successfully treated with antibiotics rather than with surgery.

Children are the most likely age group to get appendicitis — but when a child is brought into the hospital, doctors may struggle to distinguish between simple and complicated appendicitis, especially at early stages of the condition. This is because, apart from taking ultrasounds, clinicians have to rely on insensitive lab diagnostic tests and scoring systems that are based on physical symptoms, such as nausea or fever. These measures can result in misdiagnosis, leading to delayed treatment, the study authors wrote. 

In their new analysis, the researchers looked at the gene activity of more than 70 children ages 5 to 17 who were hospitalized with suspected appendicitis in Canada. They found that the kids could be retroactively diagnosed as having either simple or complicated appendicitis based on the level of activity of four genes. The researchers measured the gene activity by looking at the amount of RNA — a molecule used to convert DNA into proteins — in samples of the children's blood taken when they were admitted to the hospital. 

The gene activity analysis delivered an accurate diagnosis 85% of the time. If the test can be used to help doctors reach accurate diagnoses faster, it could help them select the best drugs, namely antibiotics, to prescribe patients and prioritize who receives surgery first, the authors wrote. 

"It is well known that the earlier the physician applies appropriate therapy, the better the outcome," Bob Hancock, co-senior study author and director of the Centre for Microbial Diseases and Immunity Research at the University of British Columbia, in Canada, told Live Science in an email. 

In the case of perforated appendicitis, "a diagnosis would indicate the use of potent antibiotics and supportive therapy as well a triage of the patient into the Intensive Care Unit," he said. 

In a separate analysis, the authors also discovered that children with perforated appendicitis had a dysregulated immune response to infection, similar to that seen in sepsis. This was evidenced by the activity of immune-related genes in their blood. Recognizing that perforated appendicitis shares features with sepsis may help doctors recognize the deadly condition as soon as patients arrive at the hospital, pediatric surgeon Dr. Maurizio Pacilli and biomedical data researcher Rishikesan Kamaleswaran wrote in a commentary of the study. 

That said, while these findings are a "step forward" in our understanding of appendicitis, the newly identified gene markers will need to be tested in more people in large clinical trials before they can be used for diagnoses in hospitals, the commentary authors wrote. 

Future research should also assess whether these tests could feasibly be put into widespread use, taking into account how much they may cost and how long they would take to perform, the commentary authors added. 

This article is for informational purposes only and is not meant to offer medical advice. 

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Some unexplained deaths of young children may be linked to seizures, according to a new study that analyzed video footage of these children's last moments.

The research is an attempt to understand sudden unexplained death in children, or SUDC, when a seemingly healthy young child dies suddenly and neither an autopsy nor an investigation into the death turns up any apparent cause. SUDC is somewhat similar to sudden infant death syndrome (SIDS), in that it often happens during sleep and in children who seem to be developing typically. However, SUDC affects children ages 1 to 18, unlike SIDS, which happens before a child's first birthday.

SUDC is rarer than SIDS — of unexplained deaths of children ages 4 or younger, SIDS accounts for 90% of cases, while SUDC accounts for 10%. The rate of SUDC in 1- to 4-year-olds is 1.5 per 100,000 children, making it the fifth-leading cause of death in this age group, according to a 2020 study. For families, the losses are haunting, said Laura Gould, a researcher at NYU Langone Medical Center and first author of the new study. 

"Losing a child is devastating, and not knowing why adds another level of trauma and difficulty," Gould told Live Science. The new study provides direct evidence of children experiencing seizures and muscle convulsions right before their deaths. However, because it included only a small group of children, more research is needed to know exactly how common convulsions are among SUDC victims. 

Related: Australia's 'worst female serial killer' freed after her children's deadly gene mutations come to light

SUDC was only defined by doctors in 2005, so research on the phenomenon is still relatively new, Gould said. The CDC now tracks cases of SUDC, but there is little data on it prior to 2005. 

Gould, who co-authored the official definition of SUDC after the loss of her own daughter in 1997, is the co-founder of the SUDC Registry and Research Collaborative (SUDCRRC), which aims to understand the causes of SUDC and has now registered more than 350 cases. 

"We are very diligent in collecting as much information about the child as we can, in terms of their medical history, family history, and DNA and other biological specimens," Gould said. 

Recently, a handful of families who enrolled in the registry reported having nursery cameras that recorded and saved video of the events. SUDC is usually unwitnessed, so such videos are a rare chance to learn what happened in the children's last sleep period, although they're, of course, very difficult to watch, Gould said. 

In the new study, the researchers analyzed the first seven videos gathered by the SUDCRRC. Eight doctors reviewed each video, including six forensic medical specialists and two specialists in epilepsy. Because the videos were so difficult to watch, all of the reviewers were offered mental health support, Gould noted. 

Two of the videos were motion- or sound-triggered, meaning the recordings captured short clips of the child sleeping. The other five videos were continuous. All five continuous videos showed the children having convulsions before they died, and one of the motion-triggered videos was also suggestive of a seizure event. 

The only previous association between SUDC and seizures was the fact that children with a history of having febrile seizures — meaning those caused by fevers — are at higher risk of SUDC. But the vast majority of kids with febrile seizures outgrow them without any negative impacts. The new work suggests a need to take a deeper look at this link, Gould said. 

One of the children in the videos did have a history of febrile seizures, she said, but the other six did not. 

It's not possible to tell from the videos what caused the seizures. But there is evidence that the seizures may have been the precipitating event that led to the deaths, Gould said. The videos did not show any evidence of anything happening just prior to the seizures, nor did the children have any heart abnormalities or genetic conditions linked to cardiac problems. In rare cases, epilepsy is associated with sudden death in other age groups, for reasons not fully understood, but none of the children in the study had a history of epilepsy.

Four of the videos continued recording after the seizures and suggested that the children survived for between 2.5 and 26 minutes before they stopped breathing. 

"There are two big questions we still don't understand: Why did these children have the seizures, and why did they die from them?" Gould said. "These were all seizures less than a minute long during sleep. We still consider them unexplained deaths, but we know that the mechanism of death involves seizures." 

In other studies, the researchers have sequenced the protein-coding genes of some children who died from SUDC, but whole-genome sequencing might point to more clues about what is going on in these cases, Gould said. The findings may also suggest that doctors should talk about the risk of SUDC with parents of children with febrile seizures or consider the merits of at-home wearable monitoring devices for those kids, she said. 

For children without a history of febrile seizures, the potential guidance is less clear.

"Most people would agree that safe sleep guidelines in infants are quite clear," Gould said. "Toddlers are at the highest risk for febrile seizures, yet the sleep recommendations around them are much more vague, so I would hope this spurs some rediscussion of that." 

The researchers' new findings were published Jan. 4 in the journal Neurology.

This article is for informational purposes only and is not meant to offer medical advice.

A new algorithm helped doctors in Tanzania cut back on kids' antibiotics prescriptions by more than 46% without compromising the children's chances of recovery, a new study reveals.

Antibiotic overuse is a major driver of drug resistance worldwide, as it pressures bacteria to evolve new strategies to survive and grow even when exposed to antibiotics. This makes bacterial infections progressively harder to treat as existing antibiotics become less effective.

Past studies suggest that, at U.S. outpatient health care facilities, at least 28% of antibiotics prescribed are not actually needed. In Tanzania, more than 50% of sick children receive antibiotics when visiting health care facilities, and most often, these are not appropriate for the given child's illness, the authors of the new study wrote.

Now, a new algorithm, described in a report published Monday (Dec. 18) in the journal Nature Medicine, has shown promise in guiding doctors to prescribe antibiotics appropriately, only when needed.

Related: Superbugs are on the rise. How can we prevent antibiotics from becoming obsolete?

The new algorithm, called ePOCT+, is a digital tool that guides health care providers through what signs and symptoms to look for in a patient; which tests to run; what the likely diagnosis is; and what the best course of treatment would be. In short, it flags when it makes sense to prescribe antibiotics and when it would not.

The algorithm can incorporate data from several quick-turnaround tests that can be conducted during a doctor's appointment, known as point-of-care tests. These include, for instance, tests for oxygen levels in the blood, the levels of oxygen-carrying protein hemoglobin in blood, and inflammation levels. These quick measures can provide hints as to whether a child has a bacterial or viral infection, whereas testing for the bacteria itself would take hours.

The trial included 40 healthcare facilities across Tanzania that were randomly split into two groups: one that used the algorithm and one that didn't.

Over the course of 11 months, the researchers monitored antibiotics prescriptions at both sets of facilities. They zoomed in on consultations for about 44,300 kids younger than age 15, ranging from infants to young teens. Most of these consultations were the patient's first visits to the doctor about a problem, while a minority were patients returning to the facility about an ongoing issue.

At health care facilities that used ePOCT+, about 23% of kid's initial consultations resulted in an antibiotics prescription, compared with more than 70% at the usual-care facilities. The return visits included in the study saw a similar-size drop in antibiotics prescriptions at facilities that used the algorithm.

Following the algorithm "resulted in a close-to three-fold reduction in the likelihood of a sick child receiving an antibiotic prescription compared to children in usual care facilities," the authors wrote in the study.

However, despite this big difference, a week out from those doctors' visits patients in both groups were doing about the same. There wasn't a significant difference in the percentage of patients who grew subjectively worse, needed hospitalization or died between the two groups. However, significantly fewer children treated at the ePOCT+ facilities had to return for a second consultation after their first.

These results suggest algorithms like ePOCT+ could help cut down on antibiotics use without harming patients, the authors concluded. However, it's important to note that, while most health care providers at the ePOCT+ facilities used the algorithm, not all did — the tool wasn't used in nearly 25% of the consultations reviewed in that arm of the study.

If the tool was used more consistently, they may have seen even better results, the authors wrote. "Widespread implementation of ePOCT+ could help address the urgent problem of antimicrobial resistance by reducing excessive antibiotic prescription in sick children while maintaining clinical safety," they concluded.

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Among people with HIV, young children are the likeliest to die while receiving treatment.

This is likely because many children under 5 already have severely weakened immune systems by the time they're diagnosed with HIV, if they are ever diagnosed, according to a Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report (MMWR) published Friday (Dec. 1).

Once on medication, young kids are also more likely than older groups to have interruptions in their treatment. HIV drugs, called antiretroviral therapy (ART), work by driving down the amount of virus in a person's blood until it's undetectable — but if treatment is stopped, viral levels rebound and the infection progresses towards AIDS.

Moreover, young children in low-resource settings, including regions in sub-Saharan Africa, suffer high death rates from other conditions, such as pneumonia and malnutrition, which compound their risk of death with HIV, according to the report.

And these death and treatment-interruption rates "are likely underreported," as children are lost to follow-up and there are inconsistencies in how the data is tracked between locations, the MMWR authors added. Children's HIV services must be prioritized in order to get more kids on consistent ART treatment and avoid preventable deaths, the report concluded.

Related: We could end the AIDS epidemic in less than a decade. Here's how.

It was already known that children under 5 are less likely to receive an HIV diagnosis and be started on ART than older age groups. But less was known about the disparities between young children and older people that are both on ART.

The new report focused on people receiving ART through the United States President's Emergency Plan for AIDS Relief (PEPFAR), a program launched in 2003 to help extinguish the HIV epidemic across the world. PEPFAR currently works in 55 countries in which 78% of people with HIV live, according to the 2023 report from the Joint United Nations Programme on HIV/AIDS (UNAIDS).

The rate of new HIV infections in kids has been falling in these countries, from 287,000 in 2010 to 109,000 in 2022, UNAIDS reported. However, when children do contract HIV, they often don't receive the treatment they need. Globally in 2022, only 57% of the 1.5 million children with HIV received treatment, and an estimated 84,000 died of AIDS-related illnesses. Only 46% of all children with HIV were "virally suppressed," meaning the virus in their blood was undetectable, compared with about 71% of all HIV-positive adults.

The new report looked at people who received ART through PEPFAR between October 2020 and September 2022. That included nearly 18 million people each quarter, including nearly 12,000 infants and 105,000 children ages 1 to 4.

Each year, nearly 5% of the treated infants died, as did 2.5% of the other children under 5. These death rates are many times higher than those in people of older ages, according to the MMWR. Children under 5 were also more likely to have pauses in treatment and less likely to be virally suppressed.

To improve matters, kids must be diagnosed as early as possible and be started on ART immediately after an HIV diagnosis. On this front, there are ongoing global efforts to ensure more children with HIV get tested and onboarded into consistent HIV care that suits their families' needs. Children must simultaneously be protected from other diseases, through vaccinations, for example, and from malnutrition, the MMWR authors noted.

One major challenge is that there are few child-friendly HIV drug formulas, but some recent advancements have helped to overcome that obstacle and make kids' ART easier to maintain.

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In mid-November, news broke of an outbreak of respiratory illness in China, raising concerns that another pandemic like COVID-19 might emerge. Now, scientists say the pathogens behind the surge are actually quite common. 

The worries of another pandemic started Nov. 13, when China's National Health Commission announced a nationwide increase in respiratory infections, mainly in children, according to the World Health Organization (WHO). Then, on Nov. 21, various media outlets reported clusters of cases of "undiagnosed pneumonia" in children in northern China, notably in Beijing and Liaoning province. The Program for Monitoring Emerging Diseases (ProMED), an international network for disease surveillance, also amplified similar news reports. 

This prompted the WHO to investigate, and on Thursday (Nov. 23), the organization confirmed that the reported increase in infections and hospitalizations among children is actually being caused by several known pathogens. 

These pathogens include the bacterium Mycoplasma pneumoniae, respiratory syncytial virus (RSV), adenoviruses and influenza. M. pneumoniae can cause bacterial pneumonia, while RSV, adenoviruses and influenza can cause viral pneumonia in severe cases.    

Chinese health authorities also told the WHO that they haven't detected any "unusual or novel pathogens or unusual clinical presentations, including in Beijing and Liaoning." In other words, this rise in infection is being caused by multiple known culprits, not a mysterious monster bug. 

Related: Who should get the new COVID vaccines? What to know about the 2023-2024 shots

"This is not an indication of a novel pathogen; This is expected," Maria Van Kerkhove, acting director of the WHO's department of epidemic and pandemic preparedness and prevention, told STAT News.  

"This is what most countries dealt with a year or two ago," when they began to lift restrictions enacted in the early pandemic, she said. China only loosened its quarantining and testing policies in December 2022.

Now that pandemic restrictions have been eased, children are more likely to catch bugs this winter that they were sheltered from before. This also means that their immune systems have not been exposed to many common viruses, and as a result, they have not yet acquired protective immunity against them — something known as an "immune deficit," Dr. Ben Marais, director of the Sydney Infectious Diseases Institute at the University of Sydney, told the Australian Science Media Centre (SMC). Children are also more likely to develop severe RSV infection and to be infected by M. pneumoniae than adults.

In addition, respiratory infections normally surge in winter. 

"This is a typical 'winter surge'' in acute respiratory infections," Benjamin Cowling, a professor of epidemiology at the University of Hong Kong, told Nature. "It is happening slightly earlier this year, perhaps because of increased population susceptibility to respiratory infections resulting from three years of COVID measures," he said. 

China also recently enhanced its disease surveillance systems, Paul Arbon, a professor at Flinders University in Australia who researches health emergencies and health system strengthening, told the Australian SMC. 

"There has been an uptick in the rates but it is that time of year and China has implemented a new national reporting system that has, as it should, picked up cases that were not reported under the old system," he said. The WHO also noted that these enhancements "may have contributed to the observed increase in detection and reporting of respiratory illness in children." 

Other countries saw similar waves of respiratory infections in children during the first winter after lifting lockdown restrictions, Francois Balloux, a professor of computational systems biology at University College London, told the U.K. SMC. In the U.S., for example, more people were hospitalized with flu in November 2022 than at any point since 2010, according to the Centers for Disease Control and Prevention (CDC). 

The WHO is still closely monitoring the outbreak in China and remains in contact with local health authorities, according to the Nov. 23 statement.

The WHO recommends that people in China follow standard measures to reduce the risk of infection, such as getting vaccinated as appropriate, wearing face masks and maintaining a safe distance from people who are ill. 

As for the rest of the world, the WHO currently advises against travel or trade restrictions, and it hasn't introduced any specific measures for people traveling to China. However, anyone who develops symptoms of respiratory illness while traveling should seek medical attention, the WHO recommends.

This article is for informational purposes only and is not meant to offer medical advice.

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Nearly 1 in 5 elementary school-age children and preteens take melatonin, a recent Colorado study has found.

In addition, some parents regularly give melatonin to their preschool-age kids, according to the research, which was published in a letter in the journal JAMA Pediatrics on Monday (Nov. 13).

These findings raise concerns because there's a lack of long-term data on the safety and effectiveness of melatonin in children, the study authors wrote. The study also hints that the underlying causes of sleep problems in children taking melatonin are often going unaddressed.

Health care providers sometimes recommend melatonin as a short-term sleep aid in children with autism and severe sleep problems, because it's specifically been studied in that population, study co-author Julie Boergers, a psychologist and pediatric sleep specialist at Rhode Island Hospital and the Alpert Medical School of Brown University, said in a statement.

"But it is almost never a first-line treatment," she said. Families are typically advised to try addressing a child's sleep issues with behavioral strategies first. "Although [melatonin is] typically well-tolerated, whenever we're using any kind of medication or supplement in a young, developing body we want to exercise caution," she said.

Related: Eating just 2 cannabis gummies can put small kids at risk of toxic effects

Melatonin gummies, capsules and liquids contain a synthetic version of a sleep-promoting hormone produced by the body. For the new research, the scientists asked parents of more than 990 children ages 1 to 13 about their kids' melatonin consumption. The survey was conducted between January and April 2023 and included parents in the area around Boulder and Denver, Colorado.

About 5.6% of the preschool-age kids had consumed melatonin in the preceding month, compared with 18.5% of elementary school-age kids and 19.4% of preteens. The typical melatonin doses increased with age, from about 0.5 milligrams in the youngest group to 2 mg in the oldest, per the parents' reports.

The number of days a week that kids took melatonin varied, but most took the supplement either one day a week or seven days a week. Many of the kids who had taken melatonin in the preceding month had been consistently taking the supplement for much longer. For preschoolers, the median duration of melatonin use was 12 months, compared with 18 months for elementary schoolers and 21 months for preteens.

The study included a relatively small sample of people who were all from one area, and it was conducted via surveys, so there's uncertainty about whether the findings apply elsewhere. However, it does still raise some red flags.

Because they're considered "dietary supplements," melatonin supplements are not as tightly regulated by the Food and Drug Administration as prescription and over-the-counter drugs are. And many melatonin gummies sold in the U.S. are inaccurately labeled, containing 74% to 347% the amount of melatonin listed, past research has found. Some products actually contain no melatonin at all, while some contain CBD, the non-psychoactive ingredient in cannabis.

And research has shown that, as melatonin supplements have grown in popularity, there's been an uptick in calls to poison control centers about children — particularly those age 5 and younger — ingesting large amounts of melatonin, with a small percentage of them experiencing severe toxic effects, such as respiratory failure or seizures.

In addition, there's little data on how or whether long-term melatonin use might negatively affect children at different stages of development, and scientists have raised questions about whether the practice could impact kids' puberty-related hormones.

"We are not saying that melatonin is necessarily harmful to children," lead study author Lauren Hartstein, a postdoctoral fellow in the Sleep and Development Lab at Colorado University Boulder, said in the statement. "But much more research needs to be done before we can state with confidence that it is safe for kids to be taking long-term."

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Drugs used to treat serious bacterial infections in children and newborns may be losing their effectiveness in many countries due to "alarmingly high" rates of antimicrobial resistance (AMR), a new study finds. 

The new analysis investigated bacterial samples from 11 countries in Southeast Asia and the Pacific, including China and India. It revealed that many antibiotics recommended by the World Health Organization (WHO) to treat life-threatening bacterial infections in children are less than 50% effective against the microbes that most commonly cause these illnesses. The dangerous infections include the lung infection pneumonia, the whole-body immune reaction sepsis and the nervous-system infection meningitis. 

While AMR is a global threat, the new findings, published Tuesday (Oct. 31) in the journal The Lancet Regional Health - Southeast Asia, are particularly concerning for many low- and middle-income countries in the Asia-Pacific where health care resources and access to new drugs are limited, the study authors said. 

"Antibiotic resistance is rising more rapidly than we realize," lead study author Dr. Phoebe Williams, an infectious disease specialist at the University of Sydney, said in a statement. "We urgently need new solutions to stop invasive multidrug-resistant infections and the needless deaths of thousands of children each year," she said. 

Related: Dangerous 'superbugs' are a growing threat, and antibiotics can't stop their rise. What can?

The rise of AMR is one of the biggest public health threats facing humanity, particularly among high-risk groups, such as children and babies. Young children face a higher risk of bacterial meningitis than other age groups, for instance. Globally, between 140,000 and 214,000 newborns are estimated to die every year as a result of microbes that are resistant to antibiotics. 

In the new study, the authors used statistical models to predict the rates of AMR in the 11 countries based on data from 86 published papers, which collectively included more than 6,600 samples of bacteria. They found that one particular antibiotic, ceftriaxone, is likely to only be able to treat 29% of cases of sepsis and meningitis in newborns in the studied countries. Similarly, another antibiotic, gentamicin, is only likely to treat 39% and 21% of sepsis and meningitis cases in children, respectively. 

The researchers predicted that carbapenems were likely the most effective antibiotics overall; for instance, they were predicted to treat 81% of cases of sepsis or meningitis in newborns. However, these antibiotics are considered a "last-resort" treatment for many drug-resistant infections, because they target an extremely wide variety of bacteria. 

Although they can be very effective, the use of these drugs needs to be carefully weighed up against the potential risk of propagating carbapenem-resistant bacteria, the authors wrote. Carbapenem-resistant strains of deadly Acinetobacter baumannii, for example, are a significant threat in hospitals.

Williams told The Guardian that the issue extends beyond updating current WHO guidelines on antibiotic use in children. 

"We need to update the guidelines, but one of the biggest problems is we're just not getting new drugs licensed for use in children and babies so there isn't really much new to recommend," Williams said. Of the 14 new antibiotics that have been licensed since 2000, only four have been licensed for use in babies because "drug companies are reluctant to do research on babies and children," she told The Guardian. 

In light of these findings, the authors wrote in the paper that new drugs to treat these common infectious diseases in children are "urgently needed" and that children and newborns should be prioritized in future clinical trials. 

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Eating just two weed gummies can put small children at risk of "severe and prolonged" toxic effects.

These toxic effects include dangerous slowing of the heart rate, plummeting blood pressure, seizures, unresponsiveness and respiratory failure, according to a new study published Monday (Aug. 28) in Pediatrics, a journal of the American Academy of Pediatrics (AAP).

The research, conducted using medical records from the Children's Hospital Colorado Network, aimed to pinpoint what dose of THC (tetrahydrocannabinol), the high-inducing ingredient in cannabis, puts young children at risk of concerning symptoms that require medical attention, and particularly symptoms that last more than six hours.

That threshold turned out to be fairly low: 1.7 milligrams of THC per 2.2 pounds (1 kilogram) of body weight, regardless of the child's age or sex. A typical cannabis gummy contains 10 mg of THC, meaning a toddler weighing 25 pounds (11.3 kg) would exceed that threshold after eating only two gummies.

Related: Delta-8 marijuana products can be dangerous, health officials warn

"With widespread cannabis legalization, we've seen a rise in unintentional cannabis exposures in children," Dr. Lesley Pepin, a medical toxicology fellow at Rocky Mountain Poison and Drug Safety in Denver and co-author of the report, said in a video accompanying the study. This trend has been particularly striking in children under 6 since 2017. "In young children, these exposures are largely attributed to edible cannabis products," such as baked goods, chocolates and gummies, Pepin said.

The trend isn't unique to U.S. states that have legalized edibles; Canadian provinces that allow the sale of THC-infused snacks have also seen upticks in pediatric hospitalizations for cannabis poisonings.

Kids who get mildly sick after consuming THC may be drowsy, have poor balance and coordination, or vomit. But in a small proportion of severe cases, THC can lead to dangerously low blood pressure, coma, respiratory depression and seizures. In many cases, the THC dose kids are exposed to is unknown. These factors have made it difficult to determine what dose predictably leads to bad outcomes in this age group, Pepin said.

To pin down a number, Pepin and her colleagues reviewed medical records for edible cannabis ingestions in children ages 6 and younger logged between January 2015 and October 2022. Across four pediatric hospitals with emergency departments and three urgent care centers, the team identified 80 cases of kids eating edibles where the cannabis product and THC dose were known.

The median age of the affected children was 2.9 years, and the THC doses consumed ranged from 0.2 mg/kg of body weight to 69.1 mg/kg. Nearly 90% of the cases involved the child finding the edible at home, and in a handful of cases, an adult mistook the edible for a non-cannabis product and gave it to the child.

Eight of the children showed no symptoms, but the remainder generally started showing symptoms about an hour after ingestion, with the most common symptoms being sedation or lethargy. Thirty-four kids required no medical treatment, and of these, most had consumed 2 mg/kg of THC or less.

"Based on our findings, a 10 mg THC ingestion would be unlikely to cause severe toxicity in most young children," the report authors wrote. However, "with each additional 1 mg/kg of THC, the odds of severe or prolonged symptoms triple."

Thirty-seven children experienced at least one severe toxic effect after consuming a median of 5.4 mg/kg of THC. In these children, symptoms lasted for a median of 20.3 hours. Some cases involved kids falling into a coma, experiencing seizures, requiring supplemental oxygen from a ventilator or needing blood-pressure-raising drugs.

"However, these manifestations were rare," the researchers wrote of the most severe cases. "The dose range to induce these symptoms was 2 to 69 mg/kg. This wide range suggests other patient characteristics may contribute to the risk of these effects." 

(The report doesn't specify what these characteristics might be, but ingested cannabis is metabolized mostly in the liver, so differences in liver function could influence how it impacts different people, for example.)

To prevent kids from eating edibles, caregivers should store the products in childproof packaging and keep them locked in out-of-reach places, Pepin told U.S. News & World Report. Family and friends outside the household should also be educated about how to safely store edibles around children, she added.

Archeologists in Tunisia have excavated rare, 2,300-year-old gold coins and urns holding the remains of animals, infants and premature babies from the ancient city of Carthage.

The researchers discovered the burials and five gold coins near the ruins of the temple of Tafat El Bony, which sits on a hill on the outskirts of Tunis. The temple was once a countryside monument dedicated to the deities Baal Hammon and Tanit, Tunisia's Ministry of Cultural Affairs said in a translated statement on Facebook.

Carthage was a powerful city-state founded by the Phoenicians — a people from the eastern coast of the Mediterranean, also known as the Levant — in the ninth century B.C. The city flourished in the sixth century B.C. and developed into a great trading empire with influence over much of the Mediterranean basin. Carthage and the Roman Republic became major rivals and fought during the lengthy Punic Wars between 264 B.C. and 146 B.C., which ended when the Romans destroyed the North African city. A new Roman Carthage was built over the ruins, and the remains of both are today listed as a UNESCO World Heritage Site.

Related: 2,000-year-old gold treasure from Iron Age tribe unearthed by metal detectorists in Wales

The newfound gold coins measure just under an inch (2.5 centimeters) in diameter, according to the Tunisian broadcaster Shems FM, and depict the ancient goddess Tanit — a symbol of fertility and motherhood for the Carthaginians. 

The coins are a rare discovery "reflecting the richness of that historical period and affirming the cultural value of Carthage," Ministry of Cultural Affairs representatives said in the statement.

Wealthy Carthaginians likely left the coins as a gift for the gods, archeologists said, but it remains unclear whether the buried infants had been sacrificed or died of natural causes. Over the past century, excavations in Carthage have unearthed thousands of tombstones and urns containing the remains of newborn babies and children up to age 4, which some experts believe could have been sacrificial offerings.

"Archaeological, literary, and documentary evidence for child sacrifice is overwhelming," Josephine Crawley Quinn, a professor of ancient history at the University of Oxford in the U.K., said in a 2014 statement. "Perhaps it was out of profound religious piety, or a sense that the good the sacrifice could bring [to] the family or community as a whole outweighed the life of the child." 

Passages in the Christian Bible describe child sacrifice to the Carthaginian deity Baal Hammon, and Greek and Roman tales also recount gory scenes of infant killings, but close examination of remains found at a suspected sacrificial ground suggested it was a regular cemetery for babies and fetuses, Live Science previously reported. 

Some experts believe the urns and tombs discovered in Carthage over the past century are the vestiges of burials for children who died of natural causes. 

But these remains are mostly cremated, and burning stillborn or dead babies would require precious wood, which the Carthaganians desperately needed for other purposes, said Patricia Smith, a biological anthropologist and professor emerita at the Hebrew University of Jerusalem, who was not involved in the new finding.

"The Carthaginians were seafarers; they needed wood for ships, they needed wood for cloth, they needed wood for their tools," Smith previously told Live Science. It is therefore likely Carthaganians only used wood resources to cremate infants as a sacrificial ritual, she said. 

A woman in Australia who spent 20 years in prison after being convicted of killing her four children has been released after new DNA evidence showed that all of the children, who died as infants over a 10 year period, possessed genetic mutations that could explain their deaths. In her initial conviction, there had been no physical evidence to suggest she'd killed the infants.     

Kathleen Folbigg, a 55-year-old woman from New South Wales (NSW), was accused of murdering her two daughters, Sarah and Laura, and son Patrick, as well as committing manslaughter against her other son, Caleb, between 1989 and 1999. In 2003, Folbigg was sentenced to 25 years in a maximum-security prison, where she remained until her release earlier this month. Due to the nature of her alleged crimes, the media nicknamed Folbigg "Australia's worst female serial killer."

But on June 5, 2023, Folbigg was pardoned by NSW Gov. Margaret Beazley and was released from prison after evidence presented at a recent inquiry suggested that her children most likely died of natural causes. The inquiry, which began in 2022, revealed that both of Folbigg's daughters had an extremely rare and previously unknown mutation of the CALM2 gene, key for shuttling calcium through tissues, that can cause sudden cardiac arrest. Meanwhile, both of Folbigg's sons carried a mutation of the BSN gene, needed to build functional brain cells, which has been linked to an early onset and lethal form of epilepsy.

The Folbigg case has been described as "one of Australia's greatest miscarriages of justice," according to the BBC.

Related: 10 bizarre medical case reports from 2022

Circumstantial conviction 

All of the Folbigg children died in their sleep when they were between 19 days and 18 months old. The first death, that of Caleb, was initially attributed to sudden infant death syndrome (SIDS). The subsequent death of his brother Patrick was never determined, although Patrick did experience seizures in the months leading up to his death, according to the BBC. 

However, the later deaths of Sarah and then Laura, whose sudden deaths could not be explained either, sparked speculation that Folbigg may have smothered each of her children to death. The accusations heavily affected Folbigg's personal life: In 2000, she was divorced by the children's father, Craig Gibson, who believed she had killed their children In 2001, she was arrested and later convicted in a nationally scrutinized trial that lasted seven weeks. Her initial sentence was 40 years but was reduced on appeal.

There was never any physical evidence that Folbigg had smothered her children. However, in a personal diary entry that Gibson provided to the police, Folbigg described how the "guilt about them all haunts me," which was used by prosecutors to infer her guilt despite the defense arguing that this was circumstantial evidence, according to the BBC.

Over the past three decades, Folbigg has continually denied that she killed her children and has had multiple appeals denied. 

New evidence 

The new inquiry was launched after researchers decided to sequence the genomes of Folbigg and her children, using preserved DNA samples, in 2018, according to Australian news outlet ABC News. (This technology was not widely available during the initial trial in 2003.)  

Their findings, which were published in March 2021 in the journal EP Europace, revealed that Sarah and Laura each carried one copy of a CALM2 variant known as CALM2-G114R, which they inherited from Folbigg.

Related: Doctors identify never-before-seen genetic mutations that led to 2 children's insatiable hunger

The CALM2 gene provides the genetic instructions needed for cells to produce the protein calmodulin, which helps regulate the movement of calcium ions in and out of cells. Calcium ions are particularly important in maintaining a regular heartbeat, so people with mutated CALM2 genes can develop calmodulinopathy, a syndrome that causes an irregular heartbeat, or arrhythmia, which can be lethal in young children, ABC News reported.

Even small changes to the calmodulin protein can be particularly destructive, due to its important job, Jozef Gecz, a human geneticist at the University of Adelaide who was not involved in the research, told ABC News. "Once you tamper with it, you introduce a problem and potential explanation why the heart may fail."

Calmodulinopathy is extremely rare. To date, only 135 people worldwide have ever been diagnosed with the condition, although experts estimate that it may affect up to 1 in 35 million people, ABC News reported.

The chances of Folbigg passing on the CALM2-G114R variant to any one of her children was 50%, study co-author Melanie Bahlo, a statistical geneticist at the Walter and Eliza Hall Institute of Medical Research in Melbourne, told ABC News.

But if Folbigg also possesses the mutated gene, why hasn't she developed calmodulinopathy?

The researchers suspect that the syndrome could be triggered in part by complementary gene variants, such a specific version of the REM2 gene, which also helps regulate calcium levels in cells. All four of the Folbigg children carry a variant of the REM2 gene, while Folbigg does not. It is likely that their father possesses the same REM2 variant, but he refused to give a DNA sample to the researchers, ABC News reported. (Around 18% of people have a mutant REM2 gene.)

Study co-author Dr. Peter Schwartz, director of the Center for Cardiac Arrhythmias of Genetic Origin in Milan, told ABC News that the Folbigg girls experienced an unfortunate "double hit" of mutations. "The combination of maternal and paternal DNA has represented a lethal cocktail," he speculated.

Both Caleb and Patrick possessed a mutated version of the BSN gene, which codes for a type of protein found primarily in brain cells. The protein is specifically found in the scaffolding at the ends of neurons' long, thin wires, from which they spew chemical messengers. Past studies in mice have suggested that this gene can cause a lethal type of epilepsy in infancy, ABC News reported. 

Prior to his death, Patrick had been hospitalized for four months due to a seizure, which suggests that he could have had this rare form of epilepsy. Caleb reportedly never had any seizures, but the fact that he also possessed the mutated BSN gene, as well as the circumstances of his siblings' deaths, was enough to establish reasonable doubt that he was killed by his mother. 

As part of the inquiry, a group of more than 90 scientists signed an open letter agreeing that all four children could have died from natural causes and urged Beazley to pardon Folbigg. 

Two children who experienced intense, insatiable hunger that drove them to overeat have rare, never-before-seen genetic mutations that interfere with leptin, a key hormone that helps tell the body when it is full, a new case report says.

After white fat cells make leptin, it plugs into the brainstem and hypothalamus, brain regions that help control appetite. While the "hunger hormone" ghrelin constantly fluctuates, rising with fasts and falling after food intake, leptin levels remain relatively steady and are related to the body's total amount of white fat. Thus, leptin tells the body how much energy it has stored in fat and shifts the body into "starvation mode" when those stores fall too low. 

Rarely, people can carry genetic mutations that interfere with the production or secretion of leptin, or effectively block its effects in the brain. Prior to the new case report, published Wednesday (June 14) in The New England Journal of Medicine, scientists had found 21 genetic variants that messed with leptin production, release or sensitivity, resulting in insatiable hunger, known as hyperphagia.

In the new case report, the authors describe two unrelated children, a 14-year-old boy and a 2-year-old girl, who carried slightly different leptin-disrupting genetic mutations.

Related: Why does hunger sometimes cause nausea? 

Both children had high levels of leptin in their blood, which coincided with their high body fat percentages. After ruling out the Prader–Willi and Bardet–Biedl syndromes — two other rare genetic conditions that can lead to high appetite and weight gain in childhood — doctors checked each child's leptin gene, called LEP. They found that each child carried a distinct version, or variant, of the LEP gene; they named the boy's P64S and the girl's G59S. These genes coded for slightly modified versions of leptin.

Through studies with human cells in lab dishes, the team tested how well the children's leptin bound to the receptor it would normally plug into in the brain. Both versions of leptin bound to the receptor, but they triggered "marginal, if any, signaling." In the presence of normal leptin, the variant versions blocked the receptor and didn't allow normal leptin to plug in.

So while the children made high quantities of modified leptin, the hormone couldn't signal to the brain that their bodies contained ample amounts of stored energy. Without this signal, the kids' appetites couldn't be sated — their brains were attempting to compensate for an energy deficit that didn't exist.  

To treat the children, the doctors provided metreleptin, a synthetic form of leptin. At first, both kids required "higher-than-usual doses" of the treatment to overcome the effects of their leptin variants in the brain. Both children also participated in fasting and exercise programs, to help reduce their white fat and therefore their leptin production. This "eventually evoked a therapeutic response, with a normalization of food intake and satiety and weight loss," the authors wrote in the case report.

Both children developed antibodies against the metreleptin, which their doctors expected, but this didn't appear to affect the drug's effectiveness. There were no serious side effects and "both patients eventually attained near-normal weight."

In a forest clearing of birch and pine trees in what is today central Europe, herds of long-extinct beasts once gathered to drink on the shores of an ancient lake. Now, researchers have confirmed that early human relatives and their children foraged and bathed among them.

Three rare, 300,000-year-old footprints from a Lower Paleolithic (around 3 million to 300,000 years ago) fossil site in northwestern Germany reveal that Homo heidelbergensis, an extinct species of human that existed from about 700,000 to 200,000 years ago, co-existed with prehistoric elephants and rhinos, whose footprints were also found at the site. While a 2018 study in the journal Scientific Reports documented a similar neighborly relationship between early humans and prehistoric beasts in Ethiopia from 700,000 years ago, this is the first footprint evidence of H. heidelbergensis from Germany and only the fourth record of the species' footprints worldwide.

"These three footprints represent a significant 'direct' proof of the hominin presence on the site," Flavio Altamura, an archeologist at the University of Tübingen in Germany and lead author of a study describing the fossils, told Live Science in an email. While one footprint clearly belonged to an adult, the others were much smaller. "Since two footprints are related to young individuals, this is also proof of the existence of children on the spot," Altamura said.

The discovery is remarkable because signs of children at prehistoric sites are scarce. Most of the evidence researchers have about the earliest periods of humanity comes from tools, human remains and food waste in the form of animal bones, Altamura explained. "You have to look for children's bones, that are very rare, and it is very hard to link tools and food waste with children's activity. So it is very difficult to say something about their behavior and the kind of life they were [leading]."

Related: Superhighway of ancient human and animal footprints in England provides an 'amazing snapshot of the past' 

The newly found footprints provide clues about what it was like to be a child 300,000 years ago. "This is a rare snapshot of childhood in prehistory," Altamura said.

The footprints reveal aspects of our human relatives' daily lives, which researchers describe in a study published May 12 in the journal Quaternary Science Reviews. The findings show that long-extinct "Heidelberg people" dwelled on the shores of an ancient lake among herds of the largest land animals at the time — prehistoric elephants called Palaeoloxodon antiquus that had straight tusks and weighed up to 13 tons (12 metric tons).

The researchers also unearthed tracks belonging to a rhinoceros, which they identified as Stephanorhinus kirchbergensis or S. hemitoechus. They are the first footprints of either species ever found in Europe.

The human footprints were probably left during a small family outing, Altamura said. "We may suggest that a small hominin group that included children was walking among elephants and other species on the muddy shore of an ancient lake, perhaps looking for and collecting food, or bathing, or just playing there."

These are not the oldest H. heidelbergensis children’s footprints unearthed among animal prints, however. A similar collection of human footprints and animal tracks was unearthed between 2013 and 2015 at a 700,000-year-old archeological site in Ethiopia called Melka Kunture. There, a cluster of tracks belonging to 11 adults and children potentially as young as 12 months old suggested that children were present when tools were made and animals butchered.

"Children and adult footprints were found on the border of a pond where other animals congregated and where hippos were butchered by hominins, suggesting that children were assisting adults and learning since their first years how to survive in the then wild environment," Altamura, who co-authored the 2018 study of the Ethiopian fossils, said.

A dingo recently attacked a 6-year-old girl while she was paddling in a shallow lagoon in Australia, holding her underwater and repeatedly biting her head.

The wild dog attacked the girl on K'gari, also known as Fraser Island, on April 3. The child is in stable condition, having suffered three puncture wounds around her ear. Rangers with the Queensland Parks and Wildlife Service (QPWS) believe the dingo responsible was an untagged male. 

"It's believed the young tourist was swimming in shallow water on the eastern side of the island when the dingo tried to grab onto her," LifeFlight rescuers said in a statement. "The animal repeatedly held her underwater for a few seconds before nearby family members were able to get the dingo off her."

Authorities reported a second dingo attack on a toddler on Friday (April 14) in Karijini National Park, in Western Australia, 932 miles (1,500 kilometers) north of Perth. The boy suffered serious but non life-threatening injuries before his mother managed to fight the animal off.

Dingoes (Canis dingo) are part dog, part wolf. They are Australia's largest carnivorous mammals and typically hunt rabbits, kangaroos, wallabies and wombats — but not humans. 

"Generally dingoes go about their lives and stay clear of people," representatives of QPWS, which is investigating the mauling, said on its website. "From time to time, dingoes may come close and some encounters can turn to tragedy."

Related: Humans are practically defenseless. Why don't wild animals attack us more?

K'gari is home to roughly 200 wild dingoes, according to the QPWS. They live in packs of up to 12 animals that patrol defined territories, but their curiosity occasionally draws them into tourist locations, where close encounters can turn nasty.

The QPWS urges visitors to clear away scraps of food and to never feed dingoes, as they may become increasingly habituated and emboldened in the presence of humans. Research suggests the availability of human food can reduce dingoes' aggression towards each other and lead to larger numbers of animals foraging together.

If they can regularly access human leftovers, dingoes may come to associate humans with food and try to steal items that they perceive as a meal. A survey of dingo attacks on K'gari between 2001 and 2015 found that more than half of the incidents involved a "chase," where a person was walking or running after a wild dog to retrieve a stolen possession. This may trigger a defensive response from dingoes and has led to aggressive group attacks, according to experts writing in The Conversation. 

Although uncommon, dingo attacks on children are often linked to food — if a baby is left sitting on a picnic rug and dogs try to pinch some food, for example — or due to defensive interactions sparked by toddlers playing or running around, according to the QPWS. Altogether, there have been 33 incidents of dingoes nipping, mouthing or biting people since 2018, according to the Queensland Department of Environment and Science.

In December 2022, a dingo repeatedly bit a 5-year-old boy on the head, arm and buttocks in a remote camping area on K'gari. The last fatal attack on the island was in 2001, when two dingoes mauled a 9-year-old boy to death after he and his brother happened upon the dogs and tried to run away.

Elementary school students in Canada recently schooled NASA scientists when they discovered that life-saving EpiPens can turn poisonous when launched into space.

Students from St. Brother André School's Program for Gifted Learners (PGL) in Ottawa were studying the effects of cosmic radiation on epinephrine, the active ingredient found in EpiPens, an emergency treatment given during severe allergic reactions. NASA selected the students' experiment to be part of Cubes in Space, its global STEM program geared specifically to school-age kids.

For the program, the 9- to 12-year-old students designed an experiment in which epinephrine samples were placed into tiny cubes and sent to the edge of space via either a high-altitude balloon or a rocket. Once back on Earth, researchers from the John L. Holmes Mass Spectrometry Facility at the University of Ottawa tested the samples and found that only 87% contained pure epinephrine, while the other 13% had been "transformed into extremely poisonous benzoic acid derivatives," according to a University of Ottawa statement.

Cosmic radiation is made of extremely high-energy particles released by stars, including Earth's sun. Our planet's atmosphere largely protects life on Earth from this radiation, but astronauts exposed to cosmic rays for a prolonged period of time face significant health risks, including radiation sickness and increased lifetime risk for cancer and other diseases, according to NASA.

Related: Man almost dies from an allergic reaction to cold air

Cosmic radiation also shows a clear impact on chemicals like epinephrine, Paul Mayer, a professor in the Department of Chemistry and Biomolecular Sciences at the University of Ottawa, said in the statement.

"The 'after' samples showed signs that the epinephrine reacted and decomposed," Mayer said. "In fact, no epinephrine was found in the 'after' EpiPen solution samples. This result raises questions about the efficacy of an EpiPen for outer space applications and these questions are now starting to be addressed by the kids in the PGL program."

While benzoic acid is naturally occurring in certain plants, including cranberries, plums and cinnamon, and is often used as a food preservative, the National Institutes of Health (NIH) classifies the colorless compound as a "health hazard" when consumed at high dosages.

The students are now designing a capsule to protect EpiPens while in space. In June they will travel to the Langley Research Center in Hampton, Virginia, to present their findings to NASA.

The American Academy of Pediatrics (AAP) released new guidelines for treating children and teens with obesity. 

The 73-page guidelines outline a proactive approach, where children and their families receive counseling about weight-loss treatments sooner, rather than later. Treatments include time-intensive programs that address children's nutrition and physical activity, as well as weight-loss drugs for children as young as age 12 and metabolic and bariatric surgeries for teens 13 and older.

The guidelines aim to curb the negative health outcomes linked to untreated childhood obesity. In both the short-term and long-term, kids and teens with obesity face an elevated risk of heart disease, high blood pressure, insulin resistance, prediabetes and type 2 diabetes. Studies suggest that a child's weight is highly predictive of weight in adolescence and adulthood, and the links between obesity and increased health risks in adults are established, the report states. So by having doctors treat obesity early, the AAP is aiming to head off a lifetime of health problems, the authors wrote. 

The new guidance received a mixed response, with some experts hailing it as an "overdue and crucial" shift in how American doctors approach childhood obesity. Others argued that it perpetuates anti-fat bias and may prompt physicians to reach for the aggressive interventions as first-line treatments, rather than last resorts.

Live Science asked experts what they think of the guidelines, and they generally agreed that the AAP presented an evidence-based review of childhood obesity and the best available treatments. However, for now, most children likely won't receive the gold standard of care recommended by the guidelines. Thus, there's a risk that harried pediatricians will recommend that children lose weight but lack the time to guide them safely through the process, potentially leaving kids vulnerable to disordered eating, one expert suggested. In addition, scientists are still learning about the long-term consequences of weight-loss drugs, they added. 

Related: How body fat is calculated

"I think the challenge is that many patients do not have access, resources, or time to participate in structured and professionally run pediatric obesity treatment," Dr. Jason Nagata, a pediatrician and adolescent eating disorder specialist at the University of California, San Francisco, told Live Science in an email. Outside of these programs, kids recommended weight loss treatment may not be adequately monitored, Nagata said.

"As an eating disorder specialist, I have received many referrals for teens who were previously told they were obese and needed to lose weight, and they took the weight loss to the extreme," he said. Research led by Nagata suggests that, compared with their leaner peers, older teens and young adults with overweight or obesity are more likely to engage in disordered eating behaviors, like fasting, but less likely to be diagnosed with eating disorders than underweight peers. That's dangerous because teens with disorders like anorexia can still be dangerously ill, even if they are not underweight. 

Doctors should discourage patients from using dangerous weight control strategies, explain the risks, and monitor the rate and degree of patients' weight loss, Nagata said, and AAP gives similar, if brief, guidance in its report. But many doctors have limited training in eating disorders and limited time to interact with their patients, Nagata said, so ensuring that kids receive this type of care could be tough.

The AAP also provides examples of neutral language to use in conversations about a child's weight, and broadly, the guidelines frame obesity as a complex, chronic disease influenced by myriad factors, from genetics to socioeconomics, rather than a "reversible consequence of personal choices," as it's been considered in the past, the guidelines authors wrote.    

The guidelines emphasize "treating the whole child," rather than fixating on a number on a scale, Dr. Sheethal Reddy, a clinical psychologist who specializes in obesity medicine at the Emory Bariatric Center, told Live Science. "The goal here is not to get kids skinny — it's not to have them fit into a certain size pair of pants," said Reddy, who until recently worked with children and teens at a pediatric obesity clinic.

In practice, that means taking a child's and their family's medical history, vital signs and labs, nutrition and physical activity habits, mental health and social circumstances into account, rather than checking only their body mass index (BMI) — an estimate of body fat calculated using weight and height. 

That said, BMI still factors into a child's evaluation, although the measure has been widely criticized as an imprecise measure of fat and poor indicator of overall health. More-precise methods of measuring body fat are more cost- and time-intensive, and thus not regularly used in clinics or in research. 

"Even though it's flawed, it's still a useful tool," Reddy said. "I sort of think of BMI as kind of the yellow traffic light" — a signal to slow down and see what else is going on with a child's health.

"The higher the percentile, the more likely it is that a child is carrying excess adiposity," meaning fat, said Dr. Sarah Hampl, chair of the AAP's Clinical Practice Guideline Subcommittee on Obesity and a lead author of the guidelines. "Overweight" is defined as a BMI at or above the 85th percentile and below the 95th percentile for children of the same age and sex, and "obesity" is defined as a BMI at or above the 95th percentile. These categories are reflected in the Centers for Disease Control and Prevention's new extended BMI growth charts for kids and teens.  

"And yet it's still only one of several measures we look at in terms of determining the child's health," and whether or not their weight is negatively affecting them, Hampl said. 

Related: High-sugar diet disrupts the gut microbiome, leading to obesity (in mice) 

If a child is recommended for weight-loss treatment, what are their options?

One is a motivational interviewing, a type of counseling where doctors help kids and their families work towards adjusting their nutrition and physical activity. A similar but more extensive intervention, called intensive health behavior and lifestyle treatment (IHBLT), focuses on introducing similar lifestyle changes and making them sustainable in the long-term.

"IHBLT is most often effective when it occurs face-to-face, engages the whole family, and delivers at least 26 hours of nutrition, physical activity, and behavior change lessons over 3 to 12 months," the guidelines state. Although backed by research, these types of programs aren't readily accessible to many kids, as few institutes host them and they're rarely covered by insurance, Reddy said.    

As an adjunct to IHBLT, doctors may offer children with obesity weight-loss drugs, provided they are age 12 and older. These treatments include Wegovy (generic name semaglutide), a once-weekly injection that affects how the brain and gut communicate and reduces the user's appetite.

Weight-loss drugs approved for children have been tested in roughly year-long trials, but we don't yet have data on what happens after five or 10 years of use, for example, Hampl said. And there aren't set recommendations as to how long children should use the medications.

Teens ages 13 and older with severe obesity — meaning their BMI is equal to or greater than 120% of the 95th percentile for age and sex — may also be referred to a specialist to be evaluated for metabolic and bariatric surgery.

Evidence suggests that these surgeries can reduce teens' weight and counter health conditions linked to obesity, such as diabetes and high blood pressure. However, eating disorder experts have raised concerns that the procedures alter how and what patients can eat, which can damage their relationship to food, NPR reported; other experts worry that doctors will turn to surgery too quickly, without exhausting other options, according to STAT. 

Others argue that surgery is just another option for patients and should be considered, if needed. 

"There is too much hype or over emphasis on the mention that [pharmacotherapy] and surgery 'MAY or CAN' be offered," said Dr. Stephen Cook, an internist and associate professor who researches childhood and adolescent obesity at the University of Rochester Medical Center, told Live Science in an email. "There are a number of steps before those could be considered, and they are only to be considered for those with more severe levels of obesity," he said. 

One day, they're a wobbly mess; the next, they're running through the halls. Or their gibberish turns to full sentences seemingly overnight. Children undoubtedly develop new skills quickly, all while learning how to effectively navigate a world that is strange and new to them. Adults, by contrast, may take many years to learn a new language or master certain elements of mathematics — if they do at all.

So, why do children learn so quickly? Is it simply a necessity, or is a child's brain more capable of taking in new information than an adult's brain is?

"It is a common way of thinking that 'children are like sponges' and have the magical ability to learn new skills faster than an adult, but there are some misconceptions here," Debbie Ravenscroft, a senior lecturer in early childhood studies at the University of Chester in the U.K., told Live Science in an email. "A child's cognitive development is age-related and, naturally, children perform worse than their older peers in most areas. However, there are times when being young confers an advantage, and this clusters around their earliest years." 

This advantage is largely due to neuroplasticity, meaning the brain's ability to form and change its connections, pathways and wiring based on experiences. Neuroplasticity is what gives children the capacity to learn — and, if necessary, unlearn — habits, routines, approaches and actions very quickly. This ability is most constant and rapid before a child's fifth birthday, when much of what they encounter or experience is novel.

"This [ability to learn quickly] is connected to several areas, including plasticity, their experiences with adults, their environment, and their biological drive to explore," Ravenscroft said. "Childhood is a place where children spend their time catching up with adults' more sophisticated abilities."

Related: Can you learn to wiggle your ears?

Language acquisition, in particular, is an area where children often have a huge advantage over adults, Ravenscroft noted. This is largely because "babies are able to tune in to the rhythm and sounds used in their native language, and can therefore become competent and fluent speakers by the age of four." This ability can help young children learn a second or third language with apparent ease, Ravenscroft said.

In a research paper published in April 2022 in the journal Perspectives on Psychological Science, the authors suggest that "human infants are born seeing and hearing linguistic information that older children and adults miss, although they lose this ability with more experience in their environments." Moreover, infants can "discriminate speech sounds and tones used in all of the world's languages, making them open to all input, regardless of the linguistic environment they are born into."

With language acquisition, time is an important variable. "If a child is not exposed to certain sound aspects of language by puberty, for example, it becomes impossible to discriminate between them," Ravenscroft said. 

Studies have found that, from birth to puberty, children are capable of learning language rapidly and effectively because of both their neuroplasticity and their "cognitive flexibility," or the ability to mentally switch between two different concepts or ideas rapidly, as well as being able to clearly think about numerous concepts at the same time. 

But what about skills other than language learning?

A 2022 study in the journal Current Biology suggests that children and adults exhibit differences in a brain messenger known as gamma-aminobutyric acid (GABA), which the research suggests stabilizes newly learned material. 

The study found that children have a "rapid boost of GABA" when they participate in visual training and that this learning continues even once the training has concluded, whereas "the concentration of GABA in adults remained unchanged," the researchers wrote in the study. The findings suggest that children's brains respond to training in a way that allows them to more quickly and efficiently stabilize new learning. Consequently, the research supports the idea that children can acquire new knowledge and skills more rapidly than adults can.

"Our results show that children of elementary school age can learn more items within a given period of time than adults, making learning more efficient in children," Takeo Watanabe, co-author of the study and a professor of cognitive, linguistic and psychological sciences at Brown University, said in a statement.

To learn quickly, however, children also need support, guidance and access to appropriate learning materials.

"While children do have the capacity to learn quickly, they will find challenges if they are not well supported by caring and compassionate adults who shape their environment and experiences," Ravenscroft said. "The best time for learning is as early as possible; reading to a baby offers a wonderful, shared bonding experience in addition to providing a love of language and ensuring connections are made in the early brain." 

Birth to age 5 is a "critical period" for children, Ravenscroft added. During these early years, a young child's brain is much busier than an adult's because the child is continually learning and figuring out the best way to approach and navigate any given situation. A child's ability to learn and understand, therefore, is linked to these interactions. 

"Very young children, for example, may have difficulty in self-regulating their emotions; but this is typical behavior, as the social brain develops almost entirely postnatally, and does not begin to mature until toddlerhood," Ravenscroft said. "What is needed is time for children to process and accept new knowledge and learning. In an endeavor to speed up children's learning, we can be guilty of rushing, whereas an environment which fosters a child's pace of learning offers so much more opportunity for children to develop a love of interacting with people and places, and engaging in active learning."

COVID-19 was the top infectious disease killer for kids and teens in the U.S. between August 2021 and July 2022, a new analysis shows. It also ranked among the leading causes of death for any reason for U.S. children and teens in the same time period, the researchers determined.

The research, published Monday (Jan. 30) in the journal JAMA Network Open, utilized data from the Centers for Disease Control and Prevention (CDC) Wide-Ranging Online Data for Epidemiologic Research (WONDER) database, which includes mortality statistics drawn from the death certificates. 

The analysis took into account only deaths where COVID-19 was listed as the underlying, or primary, cause of death, as opposed to a contributing factor. In the study timeframe, 821 people ages 19 and younger died of the disease; that's an overall death rate of about one COVID-19 death per 100,000 people in the age group. 

"COVID-19 deaths constituted 2% of all causes of death in this age group," the researchers reported.

To put this death toll in context, the team pulled child and teen mortality data from 2019, before the pandemic began. In doing so, they checked the National Center for Health Statistics' ranked list of causes of death, where the causes are ordered by the frequency at which they're reported. 

Related: The 'Kraken' COVID subvariant: What to know about quickly rising omicron descendant 

Placed within this list, the rate of COVID-19 deaths in the study period exceeded the rate of influenza and pneumonia deaths in 2019 — reported at 0.6 deaths per 100,000 people — and fell just short of deaths caused by heart disease — 1.1 deaths per 100,000 people. That placed COVID-19 eighth out of the 10 ranked causes of death. 

If the team excluded deaths unrelated to disease, meaning those caused by unintentional injuries, assault or suicide, COVID-19 ranked fifth out of the remaining causes of death. (Unintentional injuries initially ranked second, at 9.1 deaths per 100,000 people, and assaults and suicides ranked fourth and fifth, respectively, at about 3.4 deaths per 100,000 people.)

"Our study period, August 1, 2021, to July 31, 2022, coincides with substantial infection waves of the COVID-19 Delta and Omicron variants," the researchers noted in their report. 

Finally, the researchers looked at the 10 leading causes of death dating back to 2015. They found that the rankings had remained largely unchanged between 2015 and 2021, with the exception of COVID-19 making the list in 2021.

"In this study, COVID-19 was a leading cause of death among individuals aged 0 to 19 years in the US," the study authors concluded. "Our findings underscore the public health relevance of COVID-19 to CYP [children and young people]."

An ongoing measles outbreak in central Ohio has sickened 74 children since mid-October, resulting in 26 hospitalizations so far, Columbus Public Health reported. There have been no reported deaths linked to the outbreak. 

Between Jan. 1 and Dec. 8, 2022, the Centers for Disease Control and Prevention (CDC) received reports of 88 measles cases across the nation, meaning most can be attributed to the Ohio outbreak. By comparison, a total of 62 U.S. measles cases were reported to the CDC in 2020 and 2021 combined. 

Of the children sickened in the Ohio outbreak, 69 out of 74 hadn't received any doses of the measles, mumps and rubella (MMR) vaccine, according to Columbus Public Health. Four children had received one dose of the vaccine out of the two recommended doses, although notably, "some cases may not have been eligible yet for the second dose due to age," the health department noted. The remaining child's vaccination status is unknown. 

The CDC recommends that children receive their first MMR dose between 12 months and 15 months old and their second dose between 4 and 6 years old. Alternatively, the MMRV vaccine, which also guards against varicella (chickenpox), may be given following the same vaccination schedule. (If traveling overseas, however, a child may need to get vaccinated at a younger age than usual, the CDC notes.)

Related: This one number shows why measles spreads like wildfire 

One dose of either vaccine is estimated to be 93% protective against measles, and two doses are 97% protective. That means there's a slim chance that vaccinated people can still become infected, but in these cases, they tend to have milder cases of the disease than unvaccinated people do, the CDC states.

In the current outbreak, 51 of the affected children, or 69%, are between 1 and 5 years old. Five of the children are between 6 and 17 years old, and 18 are younger than 1. In general, children younger than 5 face a high risk of complications from measles, according to the CDC. These complications include ear infections, diarrhea and dehydration, as well as more-severe, potentially life-threatening conditions, such as pneumonia and brain swelling (encephalitis), the latter of which can lead to convulsions and changes in hearing ability and cognitive function. 

Measles spreads through an infected person's coughs and sneezes, which release viral particles that can be inhaled or picked up from contaminated surfaces by other people. The incredibly infectious virus infects an estimated 90% of unvaccinated people who spend time near an infected person, and the virus can remain infectious and suspended in the air for up to two hours after the infected person exits the room, according to the CDC. 

In general, measles symptoms begin one to two weeks after exposure; initial symptoms can include cough, runny nose, watery eyes and a fever higher than 104 degrees Fahrenheit (40 degrees Celsius). Then, white dots known as "Koplik spots" appear in the mouth, and a red, splotchy skin rash emerges on the face and then spreads to the neck, trunk, arms, legs and feet.

"There's no way of knowing which children will become so sick they have to be hospitalized," Columbus Public Health spokesperson Kelli Newman told CNN. "The safest way to protect children from measles is to make sure they are vaccinated with MMR." 

Adults without "presumptive evidence of immunity" — meaning a record of MMR vaccination or blood test results showing that they're immune to measles — are also recommended to get at least one dose of the vaccine, the CDC states. Certain adults in this group should get two doses, including students at post-high-school educational institutions, health care personnel, international travelers and those who will be in other settings that pose a high risk for measles transmission.

Thousands of years ago, children from the Iberian Peninsula carved pieces of slate into the shape of owls, creating palm-sized toys to play with, a new study suggests. Originally, archaeologists thought the cartoonlike figures were sacred objects representing deities, used only in rituals. But a new study reveals that they also could have served as children's toys or amulets.

To investigate, researchers from the Spanish National Research Council (CSIC) examined 100 of the approximately 4,000 engraved slate owl plaques that have been collected over the years at tomb and pit sites scattered throughout the peninsula. All of the carvings dated to the Copper Age (3500 B.C. to 2750 B.C.) and were rated for how many owlish features they had, including two circles for the owl's large frontal eyes, etchings of a beak, wings, plummage and other noticeable characteristics of the birds of prey. Each piece also contained two small perforations at the top, which researchers think could have been used to weave in actual bird feathers.

"My first impression when looking at the engravings was that they were simple to make," Juan J. Negro, the study's lead author and a biologist in the Department of Evolutionary Ecology at the CSIC, told Live Science. "[The carvers] didn't invest a lot of time or skills into making them, and they could be finished in a few hours."

Another commonality among the carvings was that they were made using slate, a soft material composed predominantly of quartz, illite and chlorite. Slate's malleability meant it could easily be carved using pointed tools made of flint, quartz or copper. "Anyone can engrave into it," Negro said, including children who were just beginning their lessons in Carving 101.

Related: Iron Age warriors were buried lying on feather-stuffed cushions, near headless owl

So what inspired these Copper Age kids to focus on owls instead of other animals?

Negro said he doesn't have an explanation for that, but "owls were a common sighting — even today in urban areas." At that time, the two most abundant owl species in that part of the world would have included the little owl (Athene noctua) and the long-eared owl (Asio otus), according to the study. 

"Most likely these youngsters lived in settlements and would see owls regularly, since they're known to get rid of rats and mice," Negro said. "Owls are different from other birds due to their large heads and frontally placed eyes, which people find striking. Because of this, if you were to ask children to draw an owl, they wouldn't need a model, since everyone has an image of an owl in their brains. They're iconic animals just like horses, dogs and elephants."

To test this theory, Negro and his team asked a group of modern-day children to draw images of owls, and the resulting artwork looked eerily similar to the ancient carvings.

"We see creating [the owls] as being part of a learning process for youngsters," Negro said.

Michelle C. Langley, an associate professor of archaeology at Griffith University in Queensland, Australia, who wrote a 2018 article on ice age children's toys but wasn't part of this study, agreed.

"Cross-cultural analysis of recent peoples across the globe all find that children — everywhere — will create their own toys," Langley told Live Science in an email. "These toys are likely to be created out of common or otherwise easy-to-get raw materials, and their form will follow what is in their surroundings. Dolls and figurines are universal and the form that [they] take will likely be of common or important animals to the community — so owls would fit that picture." 

The findings were published Dec. 1 in the journal Scientific Reports.

Editor's note: This page was last updated on Aug. 24, 2023 following the approval of various RSV vaccines and a new preventative, antibody-based drug. 

Respiratory syncytial virus, or RSV, is a very common respiratory virus, particularly among children. 

Indeed, "by age 2, 90% of people have had at least one infection" with RSV, said Dr. Octavio Ramilo, chief of infectious diseases at Nationwide Children's Hospital in Columbus, Ohio, who studies RSV. But people can catch the virus at any age, and become infected multiple times. 

In healthy children and adults, the virus typically causes mild, cold-like symptoms, but it can cause more serious disease in infants younger than 12 months old, or adults over age 65, according to the Centers for Disease Control and Prevention  (CDC). In these more serious cases, the virus spreads from the upper respiratory tract to the lungs, potentially leading to pneumonia, inflammation of the lungs' air sacs (alveoli), or bronchiolitis, inflammation of the lungs' small airway passages.

Infants are particularly at risk for severe disease because of their tiny airways — which, when inflamed, can easily compromise breathing — as well as their immature immune system, Ramilo said. 

"When you look at the number one cause of hospitalization in the first year of life, the number one is RSV," Ramilo told Live Science. It's a "very problematic pathogen," Ramilo added, and the infection leads to millions of doctor visits and thousands of hospitalizations each year.

Related: The deadliest viruses in history

What are the symptoms of RSV?

Symptoms of RSV often resemble those of the common cold. According to the CDC, typical symptoms include:

•  Runny nose/congestion 
•  Coughing 
•  Sneezing 
•  Fever 
•  Decrease in appetite 
•  Headache 

In infants, additional symptoms can include fussiness and poor feeding, according to the American Academy of Pediatrics (AAP).

Symptoms typically appear within four to six days of exposure to the virus, according to the Mayo Clinic. In severe cases, the Mayo Clinic says symptoms can also include:

•  Wheezing 
•  Difficulty breathing or rapid breathing 
•  A bluish color of the skin caused by lack of oxygen 
•  Severe cough 

People should seek immediate medical care if they experience difficulty breathing, a high fever or a blueish color of the skin, according to the Mayo Clinic. 

How does RSV spread?

RSV can spread through the air when an infected person coughs or sneezes, or through contact with contaminated surfaces. The virus can survive for up to six hours on hard surfaces, such as toys and doorknobs, and can survive for about 30 minutes on unclean hands, according to AAP. 

Children often spread the virus to others at school or in daycare settings, according to the CDC. Those who are infected with the virus are typically contagious for three to eight days; but people with an immunodeficiency may be contagious for much longer, up to four weeks and even after symptoms clear up.

Is RSV seasonal?

In the U.S., RSV typically circulates from late fall to early spring, but the exact timing in a given region can vary from year to year, according to the CDC. 

The COVID-19 pandemic also disrupted the timing of RSV season, leading to unusual summer outbreaks and earlier-than-average seasons. According to a report published in July 2021 in the CDC journal Morbidity and Mortality Weekly Report, RSV activity in the U.S. dropped to historically low levels from about April 2020 to April 2021. But when COVID-19 restrictions began to lift in the spring of 2021, RSV surged, leading to a summer spike in RSV infections, the report said.

The reason behind these trends still isn't clear, Ramilo said. Although some experts suspect that measures to reduce the spread of COVID-19 taken in 2020, such as mask-wearing and social distancing, also reduced the spread of RSV, Ramilo said he doesn't think this is the whole story. "I don't think we can explain everything from nonpharmaceutical interventions" like masking wearing and social distancing, said Ramilo, who noted that other respiratory viruses, such as rhinovirus and adenovirus, still circulated in 2020, despite restrictions. 

What is clear is that the summer of 2021 saw a dramatic increase in RSV hospitalizations. "Here, we saw a big increase in July and August," at the same level that's usually seen in December or January, Ramilo said. In 25 years of studying RSV, "this is the first time we've seen an outbreak in the middle of July and August," he said.

Related: 20 of the worst epidemics and pandemics in history

Is RSV the same as COVID-19?

RSV is different from COVID-19. RSV belongs to a family of viruses known as pneumoviruses, whereas SARS-CoV-2, the virus that causes COVID-19, belongs to a group of viruses known as coronaviruses. Since RSV and SARS-CoV-2 are both respiratory viruses, their symptoms can be similar, according to the Mayo Clinic.

It is possible to be infected with both RSV and COVID-19, but such coinfections do not appear to be common, Ramilo said. Doctors have been on the lookout for these coinfections because it's known that children can sometimes be infected with RSV and other coronaviruses that cause the common cold, Ramilo said. But "we haven't seen very many cases [of RSV and COVID-19 coinfections], just a handful," he said.

What are the risk factors for RSV?

According to the CDC and AAP, people at risk for severe RSV infections include:

•  Premature babies, particularly those born before 29 weeks 
•  Children younger than 2 years old with congenital heart disease or chronic lung disease 
•  Children or adults with weakened immune systems due to a medical condition (such as cancer) or medical treatment (such as an organ transplant) 
•  Adults older than 65, especially those with chronic heart or lung disease 

Every year in the U.S., the virus leads to approximately 2.1 million doctor's visits among children younger than 5 and about 58,000 to 80,000 hospitalizations in the same age group, the CDC estimates. It's the most common cause of hospitalization in infants, and annually, 100 to 300 children under 5 die from the infection in the U.S.

Among adults ages 65 and older, RSV leads to 60,000 to 160,000 hospitalizations each year and about 6,000 to 10,000 deaths in the U.S.

 Related: 28 devastating infectious diseases 

How is RSV treated?

There's no specific treatment for RSV. Because RSV is caused by a virus, not a bacterium, antibiotics won't work to treat the infection. Most people who catch RSV get better within a week or two without medical intervention.

Over-the-counter medicines, such as acetaminophen or ibuprofen, can help manage symptoms, such as pain and fever. Children should never take aspirin, according to the CDC. People can also use nasal saline drops and suctioning to help with a stuffy nose, according to the Mayo Clinic. Those with an infection should drink plenty of fluids to stay hydrated. 

RSV may also increase the risk of ear infections in children, according to the AAP. If a child develops a bacterial ear infection, their doctor may prescribe antibiotics.

In rare cases, people with RSV are hospitalized, and their treatment in the hospital may include fluids, additional oxygen or use of a mechanical ventilator to help with breathing.

In the U.S., about 3% of infants with RSV infection need to be hospitalized, Ramilo said. But most are able to go home within two to three days, according to the AAP. 

How to prevent RSV spread

Basic hygiene measures can reduce the risk of RSV infection, according to the Mayo Clinic, including:

•  Frequent hand washing 
•  Regular cleaning of frequently-touched surfaces, such as doorknobs, as well as children's toys 
•  Covering coughs and sneezes (with your sleeve rather than your hands.) 
•  Avoiding contact with sick people 

People who have cold symptoms should steer clear of those at risk for severe disease from RSV.

Is there a vaccine for RSV?

There are two FDA-approved vaccines for RSV — one for older adults, and one for both older adults and pregnant people. 

The FDA approved the first-ever RSV vaccine in May 2023. The shot, called Arexvy and made by the pharmaceutical company GSK, is approved for adults ages 60 and older.

The vaccine contains an adjuvant, a substance that revs up the immune system, and a lab-made version of a protein found on the surface of the virus. The virus uses this fusion, or "F" protein, to break into cells. The shot trains the immune system to recognize what the F protein looks like in its "prefusion" form, the shape it's in before it infects cells.

The second RSV vaccine approved by the FDA is called Abrysvo. Made by Pfizer, the shot was approved for older adults in May 2023 and for pregnant people in August 2023. Like Arexvy, Abrysvo contains lab-made perfusion F proteins. Neither vaccine contains preservatives, according to their drug labels.

Read more about the vaccines and who should get them.

Are there drugs to prevent RSV?

There are two antibody-based drugs available to protect infants and some young children from RSV.

These injectable drugs, called monoclonal antibodies, are given to infants during their first RSV season. And some older children at high risk of infection are recommended the shots in their second RSV season. 

The shots contains lab-made proteins that mimic antibodies made by the immune system. This type of drug doesn't train a child's immune system to make its own RSV-fighting antibodies, like a vaccine would. Instead it provides a ready-made supply.

Read more about the monoclonal antibodies, who should get them and when. 

Additional resources

Read more about RSV in infants and children, from the American Academy of Pediatrics. Get more details on RSV symptoms and care, from the CDC. Find information on RSV risks and complications, from the Mayo Clinic. 

This article is for informational purposes only, and is not meant to offer medical advice.   

A Stone Age burial in Finland holds the remains of a child, as well as an assortment of grave goods, bird feathers, canine hairs and plant fibers, giving archaeologists insight into burial practices from that time period.

First discovered in 1991 in Majoonsuo, an archaeological site near the town of Outokumpu in eastern Finland, the grave contains the teeth of a child, who, based on a dental analysis, died between the ages of 3 and 10. Archaeologists from the Finnish Heritage Agency, a cultural and research institution in Helsinki, determined it was a grave site based on red ochre — an iron-rich soil commonly associated with burial sites and rock art — that had stained a gravel roadway. The agency’s excavation team examined the site in 2018 and determined that it was "at risk of destruction," according to a statement.

Based on the trapezoidal shape of two arrowheads made of quartz, the archaeologists determined that the grave dates to the Mesolithic period, or Middle Stone Age, roughly 8,000 years ago. After analyzing soil samples, the researchers discovered barbules from the feathers of waterfowl that could have been used to create a bed of down feathers for the child; they also found a single falcon feather fragment. This falcon feather may have been fletching that helped guide an arrow, or perhaps a decoration on a garment, the researchers said.

At the base of the burial lay 24 fragments of mammalian hair. While many of the hairs were badly degraded, the researchers determined that three came from a canine, possibly a wolf or a dog that may have been laid at the feet of the child as part of the burial. It's also possible that the canid hairs came from clothing, such as footwear crafted from dogskin or wolfskin, worn by the child, the teams noted.

Related: Burial of infant 'Neve' could be oldest of its kind in Europe

"Dogs interred with the deceased have been found in, for example, Skateholm, a famous burial site in southern Sweden dating back some 7,000 years," Kristiina Mannermaa, a researcher and associate professor in the Department of Cultures at the University of Helsinki, said in the statement. "The discovery in Majoonsuo is sensational, even though there is nothing but hairs left of the animal or animals — not even teeth. We don't even know whether it's a dog or a wolf." 

She added, "The method used demonstrates that traces of fur and feathers can be found even in graves several thousands of years old, including in Finland."

In addition, archaeologists unearthed plant fibers, possibly from willows or nettles, that might have been used to make clothing or fishing nets. Because soil in this area of Finland is highly acidic, the archaeologists were surprised at how well some of the organic remains have lasted over the centuries.

"The work is really slow and it really made my heart jump when I found minuscule fragments of past garments and grave furnishings, especially in Finland, where all unburnt bones tend to decompose," study lead author Tuija Kirkinen, a postdoctoral researcher in the Department of Cultures at the University of Helsinki, told CNN. "This all gives us a very valuable insight about burial habits in the Stone Age, indicating how people had prepared the child for the journey after death."

The findings were published Sept. 27 in the journal PLOS One.

The seasonal flu shot is a yearly vaccine administered to protect against the flu, or influenza. In the United States, flu shots are recommended for everyone ages 6 months and older, according to the Centers for Disease Control and Prevention (CDC). 

The flu can be a very serious illness, especially in young children, adults ages 65 and over, those with underlying health conditions and pregnant women. The flu shot is the best way to protect yourself and your family from the flu, according to the CDC.

Strains of the flu virus are constantly changing, so a new flu vaccine is made each year. Scientists make the vaccine before the flu season starts by predicting which flu strains are likely to be the most common during the upcoming season.

"Since the flu virus frequently drifts in its genetic composition, you have to reformulate the vaccine, and this is one of the reasons that people have to [get a flu shot] on an annual basis," Dr. William Schaffner, a preventive medicine and infectious disease expert at the Vanderbilt University School of Medicine in Tennessee told Live Science.

When should you get a flu shot?

Exactly when the flu season starts and ends is unpredictable, so health officials recommend that people get their flu shot in early fall, ideally by the end of October, according to the CDC. Flu activity typically peaks in February.

"We'd like to get as many people protected against influenza before influenza becomes active in communities across the country," Schaffner said.

Most flu vaccines are given before Thanksgiving, Schaffner said, but people can still get their shot throughout the winter months. Each season's flu shot expires in June of that year, but Schaffner said he would consider it "too late" to get a flu vaccine after March, unless a person is traveling to the Southern Hemisphere (where the flu season will then be starting).

After vaccination, it takes a person about two weeks to build up immunity against the flu.

People can visit the CDC's Vaccines.gov website to find flu shot locations.

Who should NOT get a flu vaccine?

Children younger than 6 months cannot get a flu shot. Those who have had a severe allergic reaction to a flu vaccine in the past should not get that type of flu shot again, and they should speak with their health care provider about whether they can receive another type of flu shot, according to the CDC. 

Similarly, people who have had a life-threatening reaction to flu-vaccine ingredients besides egg proteins shouldn't get flu vaccines with those ingredients, and they should speak with their health care provider about whether there is a flu vaccine that's right for them, the CDC says. These other ingredients might include gelatin or antibiotics, which are added to some flu shots to prevent bacterial contamination during manufacturing. (Not all flu shots contain antibiotics.)

People with egg allergies can still receive any type of flu shot that's recommended for their age group, even if the flu shot is made with egg-based technology (and thus contains a small amount of egg protein), according to the CDC. Studies have found that people with egg allergies are very unlikely to experience a severe reaction to flu vaccines. People who've had a severe allergic reaction to eggs should get their flu shot under the supervision of a health care provider who can treat severe allergic reactions, the CDC says. In addition, several types of flu shots are egg-free, including recombinant flu vaccines and cell-based flu vaccines. 

People with a history of Guillain-Barré syndrome (GBS), a rare, acute autoimmune disease that can cause paralysis, should talk with their doctor about whether they can get a flu vaccine. Some people with this condition cannot get a flu shot, according to the CDC. The cause of GBS is not known, but it is often linked with infections with viruses or bacteria; and in very rare cases, the condition has been linked with flu vaccination.

If you're not feeling well, you should talk to your doctor before getting a flu shot while you have symptoms. You should not get the flu vaccine if you have a high fever; you should wait until the fever is gone, according to Schaffner. However, if you have a minor illness, like a mild cold or a headache, you may still be able to get a flu shot.

Flu shot side effects

According to the CDC, mild side effects from the flu shot include soreness, redness or swelling at the injection site; low-grade fever; and aches. Only about 1% to 2% of people who get a flu shot will have fever as a side effect, Schaffner said. These mild effects should go away within a few days.

Rare but serious side effects can occur, including allergic reactions. Symptoms of serious side effects include difficulty breathing, swelling around the eyes or lips, hives, racing heart, dizziness and high fever, according to the CDC. If you experience serious side effects, you should seek medical care immediately. In addition, it's important to ask your health care provider to file a Vaccine Adverse Event Reporting System report either online or by calling VAERS at 1-800-822-7967, the CDC says.

The flu nasal spray vaccine, which is approved for healthy, non-pregnant people ages 2 to 49, can cause a slightly different set of side effects compared with other types of flu shots. For children, side effects of the flu nasal spray can include runny nose, wheezing, headache, vomiting, muscle aches and fever. For adults, side effects from the nasal spray might include runny nose, headache, sore throat and cough. These side effects last a short time compared with the actual flu illness, the CDC says.

How effective is the flu vaccine?

The effectiveness of the seasonal flu vaccine depends upon several factors, including how well the flu strains in the vaccine match the strains in circulation. Some studies show that when the strains in the vaccine are a good match with the ones that are circulating, vaccinated individuals are 40% to 60% less likely to visit the doctor for flu illness than people who aren't vaccinated, according to the CDC.

Flu vaccine effectiveness can also vary depending on the age and health status of the person being vaccinated. For example, older adults may have a weaker immune response to the H3N2 component of the flu vaccine (the component that protects against the H3N2 flu strain), according to the CDC.

Benefits of the flu vaccine

But even though flu vaccines don't offer 100% protection against illness, there are numerous benefits to vaccination. For example, several studies have found that individuals who do get sick with the flu develop less-severe symptoms if they are vaccinated. A 2021 study published in the journal Vaccine that reviewed data from multiple flu seasons found that, among adults who were hospitalized with the flu, those who were vaccinated were 26% less likely to be admitted to the intensive care unit (ICU), and 31% less likely to die from flu, compared with those who were unvaccinated, according to the CDC. And according to a 2018 study, among adults admitted to the ICU for flu between 2012 and 2015, vaccinated patients spent four fewer days in the hospital, on average, than those who were not vaccinated.

Related: Why is the flu shot less effective than other vaccines?

What kinds of flu shots are there?

Flu shots known as "quadrivalent vaccines" protect against four strains of flu virus. These include two influenza A strains H1N1 and H3N2 — and two influenza B strains — the lineages B/Yamagata and B/Victoria. All flu shots for the 2022-2023 flu season are quadrivalent, according to the CDC.

In addition to the standard-dose flu vaccine given through a needle, flu shots are available in several other forms. These include a high-dose version for people ages 65 and older; an "adjuvanted" version that contains an ingredient that helps boost the immune response to the vaccine for ages 65 and older; a "cell-based" version that's grown in animal cells rather than in hens' eggs and is approved for people ages 6 months and older; a "recombinant" vaccine that does not use the full influenza virus or chicken eggs in the production process and is approved for people ages 18 and older; and a nasal spray, which is approved for healthy people ages 2 to 49 but not for pregnant women or those with weakened immune systems.

There is also a needle-free flu shot, delivered by a so-called jet injector, which uses a high-pressure stream of fluid to inject the vaccine, the CDC says. It is approved for adults ages 18 to 64. 

Starting in the 2022-2023 flu season, the CDC recommends that people ages 65 and older preferably get vaccinated with one of the three following flu vaccines: the high-dose flu vaccine, called Fluzone High-Dose Quadrivalent vaccine; the adjuvanted flu vaccine, called Fluad Quadrivalent adjuvanted flu vaccine; or the recombinant flu vaccine, called the Flublok Quadrivalent recombinant flu vaccine. This recommendation was made because recent studies suggest that these vaccines are potentially more effective for older adults compared with other versions of the flu shot, according to the CDC. Among these three vaccines, the CDC does not recommend one over the other, as they were all linked with increased protection for older adults. But if the recommended shots aren't available, older adults shouldn't wait to get vaccinated and should receive a standard-dose version of the shot instead.

What's in this year's flu vaccines?

The composition of the 2022-2023 flu shot is different from last season's flu shot. Specifically, one influenza A component of the flu shot (H3N2) and one influenza B component of the shot (Victoria lineage) were updated for the 2022-2023 season. 

According to the CDC, the 2022-2023 quadrivalent egg-based flu shot contains the following strains of the flu virus:

• A/Victoria/2570/2019 (H1N1) pdm09-like virus
• A/Darwin/9/2021 (H3N2)-like virus (updated from last year's shot)
• B/Austria/1359417/2021-like virus (B/Victoria lineage) (updated from last year's shot)
• B/Phuket/3073/2013-like virus (B/Yamagata lineage)

Then, there are the two types of flu vaccines that don't involve eggs: cell-based and recombinant-based flu vaccines. In cell-based flu vaccines, the inactivated flu virus is grown in cultured cells from mammals rather than in hens' eggs. Recombinant flu vaccines are created synthetically: To make this type of vaccine, scientists combine a lab-made antigen specific to the flu virus with a baculovirus (this type infects only invertebrates, not humans).

For the 2022-2023 season, these two types of flu vaccines contain the same components as the egg-based vaccine except the H1N1 component, which in the cell- or recombinant-based flu vaccines will be A/Wisconsin/588/2019 (H1N1) pdm09-like virus, according to the CDC.

What's flu activity like this season?

As of mid-September, flu activity in most of the U.S. was low or minimal. But activity is already increasing in Texas, New Mexico and Georgia, which are currently reporting moderate levels of flu activity, and the District of Columbia, which is reporting high flu activity, according to the CDC.

Even if flu activity is currently low in your community, you shouldn't wait to get your flu shot. Flu activity could begin to increase at any time, and it takes people about two weeks after receiving their shot to develop antibodies against flu viruses, the CDC says.

Some health experts are warning that flu season could be bad this year, based on what was seen in the Southern Hemisphere, which experiences its flu season during the summer months.

"I do think it's going to be a worse year [for flu] than we've seen in the last few years," Dr. Bessey Geevarghese, a pediatric infectious disease physician at Northwestern Medicine Central DuPage Hospital in Illinois, told The New York Times. The end of most COVID-19 restrictions has opened the door for the return of flu. What's more, people are likely more susceptible to flu this year because they've had less exposure to the virus over the past two years during the pandemic, Geevarghese told the Times.

Flu shot and COVID-19: Your questions answered

How do I know if I have the flu or COVID-19?

Symptoms of COVID-19 and the flu can be similar, but your doctor can order a test to determine if you have COVID-19 or the flu. There are even tests that check for both flu viruses and SARS-CoV-2, the virus that causes COVID-19, at the same time. 

Should I get a flu shot during the COVID-19 pandemic?

Yes, getting a flu shot every year is the best way to protect yourself and others from the flu. You can take precautions to protect yourself from COVID-19 while getting a flu shot, such as getting vaccinated against the coronavirus and wearing a mask.

Will a flu vaccine protect against COVID-19?

No, flu shots do not protect against SARS-CoV-2. (Separate vaccines against SARS-CoV-2 have been approved or authorized for emergency use in the U.S.) But flu shots do protect against strains of seasonal flu viruses and can reduce your risk of getting sick from the flu, as well as the risk of hospitalization and death from flu, according to the CDC.

Can I get a COVID-19 shot and flu shot at the same time?

Yes, people can get a flu vaccine and a COVID-19 vaccine — including the new COVID-19 bivalent booster shot — at the same time, according to the CDC. People tend to experience a similar set of side effects, and receive the same protection from diseases, whether vaccines are given alone or with other vaccines, according to the CDC. However, people may be slightly more likely to experience systemic side effects, such as fatigue and muscle aches, if they receive both shots at the same time. A study published July 15, 2022, in the journal JAMA found that people who got a flu shot and a COVID-19 booster shot at the same time were 8% to 11% more likely to have systemic side effects, compared with people who received just a COVID-19 booster shot. But these side effects tended to be mild and resolve quickly, according to the CDC.

If you haven't been vaccinated against COVID-19, you should get vaccinated as soon as possible to protect yourself from the disease and stay up to date with COVID-19 booster shots, and you should aim to get a flu shot by the end of October.

Myth #1: You get the flu from the flu shot.

"It's a myth that you can get flu from the flu vaccine," Schaffner said.

The viruses in the flu shot are killed, so people cannot get the flu from a flu vaccine. However, because it takes about two weeks for people to build up immunity after they get the flu vaccine, some people may catch the flu shortly after they've been vaccinated if they are exposed to the flu during this time period. Some people may also mistakenly attribute symptoms of a cold to the vaccine, Schaffner said.

The nasal spray vaccine contains a "live attenuated" flu virus, but the virus is weakened so that it cannot cause the flu. The viruses in the nasal spray can't replicate in the warm temperatures of the lungs and other parts in the body. However, because temperatures in the nose are colder, the virus causes a small infection in the nose. This infection does not cause symptoms in most people, but in some people, it causes symptoms such as runny nose and sore throat, Schaffner said. These symptoms are typically short-lived, the CDC says.

This local infection will prompt the body to make antibodies against the flu virus, Schaffner said. "That provides better protection against the real flu, which is, of course, a virus that can make you seriously ill," Schaffner said.

Myth #2: The flu vaccine isn't safe for pregnant women.

Studies show flu vaccines are safe for women in any stage of pregnancy, the CDC says. There are several reasons why it's important for pregnant women to get a flu shot, Schaffner said.

"Pregnant women, when they get influenza, have a tendency to get a more severe disease" and are at increased risk for complications and hospitalization from the disease, Schaffner said.

In addition, flu vaccination in pregnancy helps to protect the baby against flu during the first six months of life, when the baby is too young to receive a flu shot, Schaffner said. The mother "passes that protection on to her newborn baby," Schaffner said.

Related: Am I pregnant? 12 early signs of pregnancy

Myth #3: Antibiotics can fight the flu if you get it.

Antibiotics only kill bacteria, but the flu is caused by a virus. Therefore, antibiotics do not help people recover from the flu.

There are antiviral drugs that can fight flu infections, but they've only been shown to work when they're given within 48 hours of the start of symptoms. "Most people, by the time they go to the doctor, they're past the 48-hour mark," said Dr. Dennis Cunningham, system medical director of infection prevention at Henry Ford Health System in Detroit.

For patients hospitalized with severe flu, the drugs may help, he said. But they aren't a cure, and for most people who aren't hospitalized, these drugs may only cut down on the duration of the flu by a day or two.

Myth #4: You don't need to get the flu vaccine every year.

There are two reasons doctors recommend that people get the flu vaccine every year, Cunningham told Live Science.

For one, the strains of the flu virus that are circulating change from year to year. "It's like the common cold — there's more than one type of virus that causes the flu," and, in fact, there are hundreds of influenza viruses, he said. Each year, health officials identify the virus strains that are the most likely to cause illness during the upcoming flu season, according to the CDC.

Second, the immunity you develop after getting the shot wanes by the following year. "If you get your shot in August, you'll be safe through March, but those antibodies won't be for the next flu season," Cunningham said.

Myth #5: It contains thimerosal, which may be harmful.

Thimerosal, a preservative that contains mercury, has never been shown to be harmful, Cunningham said. The type of mercury linked with nervous system damage is called methyl mercury, he said. Concerns over levels of methyl mercury have led to recommendations that pregnant women avoid eating large amounts of certain types of fish, such as swordfish.

In contrast, thimerosal is an ethyl mercury compound that has antimicrobial properties. Still, because the preservative raised controversy, especially over a now-disproven link to autism, it was taken out of almost all U.S. vaccines starting in 2001, Cunningham said.

The injectable form of the flu vaccine is available to health care providers as large, multidose bottles and small vials carrying individual doses. A tiny amount of thimerosal is added to the multidose bottles to ensure that no bacteria will grow in the vaccine, Cunningham said. The individual-dose bottles contain no thimerosal. 

The nasal spray form of the flu vaccine also contains no thimerosal, he noted.

Myth #6: The flu isn't serious.

"The flu is certainly a very serious disease," Cunningham said.

Every year, between 15 million and 60 million cases of the flu are reported in the U.S., Cunningham said. More than 200,000 people with the flu are admitted to hospitals yearly, and between 3,000 and 50,000 people in the U.S. die of the flu annually. During the 2019-2020 flu season (the last flu season with data available before the COVID-19 pandemic), the CDC estimated that 38 million Americans were infected with the flu and 22,000 people died from it.

One reason people may not perceive the flu as being serious is that cases of the "stomach flu" are mistaken for influenza virus infections. "True influenza is an infection of the lungs and respiratory tract," Cunningham said. Infected people may develop a high fever, body aches and nasal congestion, he said.

People with the stomach flu — which is commonly caused by a type of virus called a norovirus — have diarrhea, cramping and other gastrointestinal symptoms. Influenza does not typically cause such symptoms.

This article is for informational purposes only and is not meant to offer medical advice.

Editor's note: This article was last updated on Sept. 22, 2022. Live Science staff writer Nicoletta Lanese and contributor Rachael Rettner contributed to this report.

Originally published on Live Science.

More than 3.8 million babies were born each year in the United States on average from 2010 to 2020, according to the National Center for Health Statistics. But in which month are the most babies born, and why?

In the United States, the month with the largest number of births is typically August, with July a close second, Brady Hamilton, a demographer with the National Center for Health Statistics, told Live Science.

For example, August saw the greatest number of births in eight of the years from 2010 to 2020, Hamilton noted. July nabbed first place in three of those years — 2014, 2015 and 2020, he said.

Related: What is the birthday paradox?

In 2021, August was again the leading month, seeing 329,978 births, compared with an average of 350,067 births from 2010 to 2020. The smallest number of births in 2021 occurred in February, which saw 266,308 births, according to the National Center for Health Statistics.

Since the full course of a pregnancy is normally about 40 weeks, or a little more than nine months, these data suggest most children in the United States are conceived in November or December, Hamilton noted. "It's a fascinating question why that is," Hamilton said.

Reproduction appears to be seasonal in many living organisms — including plants, insects, reptiles, birds and  mammals — likely to help maximize their chances of reproduction over the course of their lifetimes, Micaela Martinez, an assistant professor of environmental health sciences at Columbia University in New York, and Kevin Bakker, previously an assistant research scientist at the University of Michigan and now a principal scientist at Merck, wrote in an essay for The Conversation.

In a 2014 study in the journal Proceedings of the Royal Society B: Biological Sciences, Martinez, Bakker and their colleagues noted that there was a clear pattern of births across latitudes in the United States: Northern states have a birth peak in June and July, whereas Southern states experience a birth peak later, in October and November.

The 2014 study found a similar pattern across the Northern Hemisphere, with peaks occurring later in the year the closer the location was to the equator. For instance, Finland saw the most births in late April, whereas Jamaica's births peaked in November.

So what could explain this correlation?

A 1990 study in the Journal of Biological Rhythms suggested the seasonality of human births may be linked with local temperature and day length. The extent to which temperature and day length may or may not change seasonally over the year depends in part on latitude, Martinez and Bakker noted. These environmental changes may influence the frequency of sex or how fertile men or women are, they noted. However, in their 2014 study, they note many other factors may play a role as well, such as income, culture, holidays and rainfall, making it challenging discussing whether and in what way temperature or day length might affect human births.

Understanding when most human births happen is more than just a matter of trivia, Hamilton said.

"If you're the birthing ward of a hospital, or a company that makes baby formula, or a diaper manufacturer, it's good to know what you might be facing over time," Hamilton said. "Further down the line, school systems may want to anticipate how many children may be coming in at a certain point in time, and health care systems would want to know what to expect in terms of inoculations."

Originally published on Live Science on July 27, 2010 and rewritten on Aug. 19, 2022.

Archaeologists recently stumbled upon a set of mysterious "ghost footprints" in the salt flats of a Utah desert. These unusual ancient tracks get their eerie name not because they are from an ethereal realm, but due to their earthly composition: They become visible only after it rains and the footprints fill with moisture and become darker in color, before disappearing again after they dry out in the sun. 

Researchers accidentally discovered the unusual impressions in early July as they drove to another nearby archaeological site at Hill Air Force Base in Utah's Great Salt Lake Desert. The team initially only found a handful of footprints, but a thorough sweep of the surrounding area using ground-penetrating radar (GPR) revealed at least 88 individual footprints belonging to a range of adults and children, potentially as young as 5 years old. (The GPR technique works by firing radio waves into the ground that bounce off objects that are hidden under the surface.)

The ghostly prints were left by bare human feet at least 10,000 years ago when the area was still a vast wetland. However, researchers suspect that the tracks could date back as far as 12,000 years ago during the final stretch of the last ice age during the Pleistocene epoch (2.6 million to 11,700 years ago).

The discovery of so many ancient footprints is a "once-in-a-lifetime discovery," Anya Kitterman, the cultural resource manager at Hill Air Force Base who oversaw the archaeological work, said in a statement. "We found so much more than we bargained for." 

However, the discovery has not yet been published in a peer-reviewed journal because researchers are still analyzing the footprints. 

Related: 100,000-year-old Neanderthal footprints show children playing in the sand 

The Great Salt Lake Desert was once covered by a large, salty lake similar to the nearby Great Salt Lake — the largest saltwater lake in the Western Hemisphere — which the desert is named after. The ancient lake slowly dried up due to changes in Earth's climate triggered by the end of the last ice age, which left behind the salts that were once dissolved in the water. But during the transition from lake to dry salt flats, the area was briefly a large wetland that was occupied by humans up until 10,000 years ago, according to the statement. 

During this time, the conditions would have been perfect to create the ghost footprints, the researchers said. 

People appear to have been walking in shallow water, with the sand rapidly infilling their print behind them, much as you might experience on a beach," lead researcher Daron Duke, an archaeologist with Far Western Anthropological Research Group, a private firm that specializes in cultural resources management, said in the statement. "But under the sand was a layer of mud that kept the print intact after infilling." The footprints have since been filled in with salt as the wetlands dried out, making them indistinguishable from the surrounding landscape when they're dry, Duke added.

Normally, when it rains, the water is quickly absorbed deep into the surrounding sediment, which means the ground quickly returns to its normal color. But when the rain falls on top of the hidden muddy footprints, the water gets trapped, creating patches of dark and wet sediment that stand out from their surroundings.

Less than a mile (1.6 kilometers) away from where the tracks were uncovered, a previous research group uncovered a hunter-gatherer camp dating to 12,000 years ago, where the humans who left the prints might have lived. Archaeological finds at the site included an ancient fireplace, stone tools used for cooking, a pile of more than 2,000 animal bones and charred tobacco seeds, which are the earliest evidence of tobacco use in humans.

The researchers involved with the new finding have collected some of the footprints in order to determine their exact age. Using radiocarbon dating, researchers hope to be able to analyze small pieces of organic material that could have been trapped in the sediment by the foot of whoever left the prints, according to the statement. 

This region is a hotspot for ancient human trackways. In September 2021, a study revealed that 60 human footprints in White Sands National Park in New Mexico dated to between 21,000 and 23,000 years ago, making them the oldest "unequivocal evidence" of humans in the Americas. These footprints were also discovered using GPR. 

"We have long wondered whether other sites like White Sands were out there and whether GPR would be effective for imaging footprints at other locations," Thomas Urban, an archaeologist at Cornell University who developed the GPR survey technique used at White Sands and more recently at the Hill Air Force Base, said in a statement. "The answer to both questions is yes."

The researchers say that these types of discoveries are important because they are direct evidence of human settlement in the area and are much more visceral than other nearby archaeological discoveries. "There is an immediate human connection to seeing human footprints," Duke said. "To see them from a distant past, especially so much different than it looks today, can be impactful."

Originally published on Live Science.

Melatonin poisoning in children has risen dramatically over the past decade, a new study suggests. 

Between 2012 and 2021, U.S. poison control centers saw a 530% increase in calls about children who had ingested large amounts of the sleep-aid supplement, the study found. 

More than 260,000 cases of melatonin ingestion were reported, and of these, more than 27,000 children required treatment in a health care facility. That includes more than 4,000 children who were hospitalized and nearly 290 kids who received care in an ICU. Five of the affected children were placed on mechanical ventilators for breathing support and two children under age 2 died. 

Hospitalizations and other serious outcomes due to pediatric melatonin ingestion have increased since 2012, primarily due to an increase in children 5 and under accidentally ingesting the drug. Researchers reported these findings in a new study, published Thursday (June 2) in the Centers for Disease Control and Prevention's (CDC) Morbidity and Mortality Weekly Report.    

"Public health initiatives should focus on raising awareness of increasing numbers of melatonin ingestions among children and on the development of preventive measures to eliminate this risk," the study authors wrote.

Related: Does melatonin work? 

Melatonin is a hormone produced by a gland in the brain that helps regulate the body's 24-hour circadian rhythm and sleep-wake cycle, Live Science previously reported. In the U.S., synthetic melatonin is available over-the-counter as a sleep aid for both adults and children.   

Because they're classified as "dietary supplements" by the Food and Drug Administration (FDA), melatonin products are subject to less regulatory oversight than prescription drugs. That means it's possible that the concentration of melatonin in a product might not match what's listed on the bottle, since the FDA doesn't confirm the label's accuracy. A 2017 study in the Journal of Clinical Sleep Medicine found that, at least in Canada, the concentration of melatonin in a supplement often varied widely from what was listed, and Canada later banned OTC melatonin due to these quality control issues. However, similar quality control studies have not been conducted in the U.S., the MMWR authors noted.

This lack of quality control, along with the rising popularity of the supplement, may increase the risk of children ingesting large doses of melatonin, the authors wrote. Plus, the same 2017 study found that some melatonin supplements contain clinically significant amounts of serotonin, which acts as a chemical messenger in the brain and can lead to dangerous side effects if taken in high doses, according to the Mayo Clinic. 

In the new study, the authors reviewed calls made to U.S. poison control centers between 2012 and 2021 and counted the number of "melatonin ingestions" reported in children, adolescents and young adults ages 19 and younger. The number of reported ingestions increased from about 8,300 in 2012 to 52,500 in 2021. The largest year-to-year increase took place between 2019 and 2020, when the rate of reporting jumped about 38%.

"Unintentional ingestions were the primary drivers of this increase," the researchers wrote in the study. "This might be related to increased accessibility of melatonin during the pandemic, as children spent more time at home because of stay-at-home orders and school closures." 

An uptick in sleeping problems during the pandemic may have also driven people to keep more melatonin in their homes. 

The majority of reported ingestions were "unintentional" and involved male children ages 5 and younger. While most cases were asymptomatic and managed at home, a minority resulted in serious outcomes, such as high fever, respiratory failure requiring intubation and seizures, some of which resolved quickly and others that progressed to "status epilepticus," a long-lasting seizure that can lead to permanent brain damage or death, the authors reported.

In general, there's little formal research about the potential side effects of kids using melatonin as a sleep aid, according to Boston Children's Hospital. However, recommended doses of the supplement seem to cause few or no short-term side effects, and if side effects do occur, they tend to be mild. Common side effects include headaches, increased bedwetting, nightmares, dizziness and morning grogginess. 

That said, because melatonin is a hormone, there's some concern that long-term use might have some effect on children's puberty-related hormones. Such effects have been noted in some animal studies, according to Boston Children's. 

Originally published on Live Science.

Brain scans of babies in the womb may reveal whether a child is at risk for developing autism later in life, early research suggests.

A small study of 39 fetuses found that, by 25 weeks of gestation, certain brain regions looked different in the unborn babies who went on to be diagnosed with autism compared with those who were not diagnosed with the condition.  

Specifically, prenatal MRI scans showed that the insular lobe — which may play a role in perceptual awareness, social behavior and decision-making — was larger in volume in the babies who would later be diagnosed with autism, compared with the insular lobes of children who were not diagnosed with autism.

Children in the autism group also had larger volume in a brain region called the amygdala in prenatal scans — a finding that jibes with earlier results showing larger amygdalae in toddlers with autism.

"These results make it clear that we need to focus on these promising regions as potential biomarkers and find out the reason for these alterations," study first author Alpen Ortug, a postdoctoral research fellow at Massachusetts General Hospital, Harvard Medical School, told Live Science in an email.

Related: What is the amygdala?

The findings add to a growing body of evidence that the disease processes involved in autism may begin early in development, the researchers said.

Still, much more research is needed to confirm the findings, which were presented Tuesday (April 5) at the Experimental Biology (EB) 2022 meeting in Philadelphia. The study has not yet been published in a peer-reviewed journal.

Autism spectrum disorder (ASD) is a developmental disorder that affects how a person communicates, interacts socially, learns and behaves, according to the National Institutes of Health (NIH).

Early detection and treatment of autism can greatly improve outcomes for patients, according to the NIH. But currently, the earliest that autism can be reliably diagnosed is about 18 months of age, the researchers said. 

Previous studies have found brain differences in infants that go on to develop autism. For example, a study published March 25 in The American Journal of Psychiatry found that the amygdala may grow too fast in babies between 6 and 12 months of age prior to their diagnosis of autism, Live Science previously reported.

In the new study, the researchers examined whether prenatal brain scans could help spot potential markers of autism even before birth. They analyzed 39 fetal MRI brain scans, which were performed at Boston Children's Hospital. The MRI scans were originally conducted because the fetuses were suspected to have a developmental condition based on ultrasound results, but the ultrasounds were not sufficient to confirm the diagnosis, Ortug said.

Among these patients, nine children were later diagnosed with autism, and 20 children had typical development. Ten of the children did not have autism but had other health conditions, such as developmental disorders affecting the cardiovascular system. The MRI scans were analyzed retrospectively, meaning after the children's diagnoses.

The researchers used a computer programming method to segment the brain scans into different regions and then compared the segmented regions among the different groups.

They found the biggest differences in the insular lobe, with significantly larger volumes in the autism group compared with the other groups. This finding agrees with previous studies that have found changes in the insular lobe in adults with autism, and suggests these changes may start in the womb, the researchers said.

Dr. L. Eugene Arnold, a professor emeritus of psychiatry and behavioral health at The Ohio State University Wexner Medical Center who was not involved with the new study, told Live Science that the new study was small and that the findings need replication but that the results are in line with other reports of various prenatal differences linked with autism. For example, a study published in January in the journal Brain that examined prenatal ultrasounds found that children who went on to develop autism were much more likely to have anomalies in their heart, kidneys and head seen on the ultrasounds, compared with children that did not develop autism.

However, Arnold also noted that differences in the insular lobe "may not be specific to ASD; they have been reported in individuals with other psychiatric disorders," including bipolar disorder. Therefore, more research would be needed to determine how specific this finding is to autism.

"Although the findings, if replicated, are enlightening … considerably more work is needed before MRIs would be a feasible way to screen for pre-ASD," Arnold said.

In addition, the study was retrospective and involved children that underwent MRIs for a suspected issue, so they are not representative of the general population.

Ortug agreed that additional, larger studies are needed to confirm the findings. If fetal MRIs become a more routine examination in pregnancy, like ultrasounds are today, they might be used to "determine whether there is an increased probability of ASD," Ortug said. "For now, as fetal MRIs are not frequent if there is no clinical indication, our results are promising for the research community rather than clinics."

Originally published on Live Science. 

The Food and Drug Administration (FDA) has approved the first drug to treat the most common form of dwarfism, known as achondroplasia.

Achondroplasia is caused by mutations in the FGFR3 gene, which encodes instructions to build a protein involved in bone growth and development, according to the Genetic and Rare Diseases Information Center. These mutations push the gene into overdrive, studies suggest, which impedes the process by which cartilage tissue gets replaced by bone; this leads to the development of short and abnormally-shaped bones and causes people with achondroplasia to be of short stature. In addition to dwarfism, the mutations can cause health complications, such as sleep apnea, recurrent ear infections, a build-up of fluid in the brain and skeletal problems that require surgery to correct.

BioMarin Pharmaceutical, a U.S.-based company, has been developing and testing a treatment for achondroplasia for years, STAT News reported in 2019. Now, as of Friday (Nov. 19), that drug has officially been approved for use in children ages 5 and up, according to a statement from the FDA. 

Related: Genetics by the numbers: 10 tantalizing tales

Clinical trials suggest that the drug, called Voxzogo, is safe and effective at restoring bone growth in children with achondroplasia and thus boosting their heights; but it's unclear whether the drug also counteracts the various health issues that can arise from the condition, STAT News reported Friday. 

Voxzogo, also known by the generic name vosoritide, works by binding to a receptor called natriuretic peptide receptor-B that is found in bone and cartilage tissues. Once attached to this receptor, the drug sets off a chain reaction that stimulates bone growth and overrides the effects of the FGFR3 mutations, according to a statement from BioMarin Pharmaceutical. 

The most recent trial of Voxzogo included 121 participants between the ages of 5 and 18 whose growth plates were still open, meaning they hadn't finished growing. The participants were randomly assigned to receive either one daily Voxzogo injection or a placebo shot, and the trial organizers assessed all the children's rate of height growth over the course of a year. 

The most common side effects of the treatment included injection site reactions, such as redness or itchiness, vomiting and decreased blood pressure, according to the FDA. By year's end, participants who received the drug grew an average 0.6 inches (1.57 centimeters) taller compared with those who received a placebo. According to BioMarin Pharmaceutical, this data suggests that, if treated throughout their childhoods, kids with achondroplasia could reach similar heights as children without the condition, STAT News reported. 

Now that it's approved, Voxzogo should be available in the U.S. this December, according to BioMarin Pharmaceutical. The list price for a year-long course of the treatment is $320,000. 

Within the dwarfism community, Voxzogo has historically drawn mixed reactions, according to STAT News. Some have expressed concern that the clinical trials exclusively focused on participants' heights, rather than their long-term health; in this way, the drug seems aimed at "correcting" short stature, which they argue isn't a problem that requires fixing. Other little people have expressed hope that the treatment will help improve people's quality of life by warding off the potential health complications of achondroplasia.

Read more about Voxzogo's recent approval and reception at STAT News. 

Originally published on Live Science.

The Centers for Disease Control and Prevention (CDC) just adjusted its criteria for what's considered a high concentration of lead in a young child's blood, the agency announced Thursday (Oct. 28).

The change applies to kids ages 1 to 5, and it could double the number of children in that age group considered to have high blood lead levels, from about 200,000 to about 500,000, The Associated Press (AP) reported.

Doctors use a so-called Blood Lead Reference Value (BLRV) as the cutoff point for what's considered a high concentration of lead; this measurement is based on the number of micrograms of lead present per deciliter of blood. For the last nine years, the BLRV was set at 5 µg/dL, and now, that threshold has been lowered to 3.5 µg/dL, according to the CDC statement. Doctors compare the amount of lead in a child's blood against the BLRV to decide who is at highest risk for negative health effects from lead.

Related: 12 worst hormone-disrupting chemicals & their health effects 

Kids whose blood levels exceed the new BLRV will have "higher levels of lead in their blood" than 97.5% of kids in the U.S., according to the CDC statement. Children whose blood lead levels exceed the cutoff should receive prompt medical care to reduce their lead levels and mitigate any damaging health effects of the exposure; children with very high levels of lead in their blood can potentially receive a treatment called chelation therapy, to remove some of the lead, according to the CDC website. 

When children are identified as having high blood lead levels, public health officials will then be responsible for identifying and eliminating the source of the lead exposure in the children's environment, the AP reported. 

"Today's action by CDC is a reminder of how important it is for parents to ask their child's doctor about early blood lead testing, so parents can take steps to keep them safe from the toxic and irreversible effects of lead exposure," Health and Human Services Secretary Xavier Becerra said in the CDC statement. Prior to the new update, blood lead levels below 5 μg/dL may or may not have been reported to parents, so with the lower cutoff, more parents, healthcare providers and communities may be notified about dangerous lead exposure in children, the CDC notes.

Children can absorb four to five times more lead than adults do when exposed to the same source, the AP reported. Lead exposure can damage a child's developing brain and other parts of their nervous system; and the toxic metal can also slow growth and development, and cause learning, behavior, hearing and speech problems, according to the CDC. 

Related: 25 scientific tips for raising happy (& healthy) kids

In the U.S., lead exposure poses the biggest problem to low-income communities and Northeast and Midwest cities with older housing, but dangerous lead exposure can occur anywhere in the country, the AP reported. "Older" housing refers to homes built before 1978, the year lead-based paints were banned, the CDC notes. Other common lead-exposure sources include: soil contaminated by historical sources of lead, such as mining; contaminated pipes and plumbing materials; contaminated jewelry, toys or (often imported) candies; and lead dust brought into the home from kids' caretakers' workplaces.

"No safe [blood lead level] in children has been identified, and even low levels of lead in blood have been shown to affect learning and academic achievement, and some effects may even be permanent," the CDC statement notes. (Detailed recommendations for preventing lead exposure, testing a child's blood lead levels and caring for children with high lead levels can be found on the CDC website.)

This recent change in the definition of lead poisoning for young children has been a long time coming, according to the AP. 

After the BLRV was last adjusted in 2012, the agency pledged to review the standard every four years. Toward the end of the Obama administration, the CDC determined that the standard should be made more stringent, but the change was held up during the Trump administration when, among other hold-ups the White House Office of Management and Budget refused to sign off, Patrick Breysse, who heads the CDC's National Center for Environmental Health, told the AP.

Originally published on Live Science.

Two teens developed severe psychiatric symptoms such as paranoia, delusions and suicidal thoughts during mild COVID-19 infections. Now, scientists think they've identified a potential trigger: Rogue antibodies may have mistakenly attacked the teens' brains, rather than the coronavirus.  

The researchers spotted these rogue antibodies in two teens who were examined at the University of California, San Francisco (UCSF) Benioff Children’s Hospital after catching COVID-19 in 2020, according to a new report on the cases published Monday (Oct. 25) in the journal JAMA Neurology. The antibodies appeared in the patients' cerebrospinal fluid (CSF), which is a clear liquid that flows in and around the hollow spaces of the brain and spinal cord. 

But while such antibodies may attack brain tissue, it's too early to say that these antibodies directly caused the troubling symptoms in the teens, the researchers wrote in the new study. That's because many of the identified antibodies appear to target structures located on the inside of cells, rather than on the outside, co-author Dr. Samuel Pleasure, a physician-scientist and professor of neurology at UCSF, told Live Science in an email.

Related: 20 of the worst epidemics and pandemics in history 

"So, we suspect that either the COVID autoantibodies" — meaning antibodies that attack the body rather than the virus — "are indicative of an out of control autoimmune response that might be driving the symptoms, without the antibodies necessarily causing the symptoms directly," he said. Future studies will be needed to test this hypothesis, and to see whether any other, undiscovered autoantibodies target structures on the surface of cells and thus cause direct damage, he added.

The study's results demonstrate that COVID-19 may trigger the development of brain-targeting autoantibodies, said Dr. Grace Gombolay, a pediatric neurologist at Children’s Healthcare of Atlanta and an assistant professor at Emory University School of Medicine, who wasn't involved in the new study. And they also hint that, in some cases, treatments that "calm down" the immune system may help resolve psychiatric symptoms of COVID-19, she told Live Science in an email. 

Both teens in the study received intravenous immunoglobulin, a therapy used to essentially reset the immune response in autoimmune and inflammatory disorders, after which the teens' psychiatric symptoms either partially or completely remitted. But it's possible the patients would have "improved on their own, even without treatment," and this study is too small to rule this out, Gombolay noted.

Possible mechanism found, but many questions remain  

Other viruses, such as herpes simplex virus, can sometimes drive the development of antibodies that attack brain cells, trigger harmful inflammation and cause neurological symptoms, Gombolay said. "Thus, it is reasonable to suspect that an association could also be seen in COVID-19."

Prior to their research in teens, the study authors published evidence of neural autoantibodies in adult COVID-19 patients. According to a report published May 18 in the journal Cell Reports Medicine, these adult patients experienced seizures, loss of smell and hard-to-treat headaches, and most of them had also been hospitalized due to the respiratory symptoms of COVID-19.

But "in the case of these teens, the patients had quite minimal respiratory symptoms," Pleasure said. This suggests that there's a chance of such symptoms arising during or after cases of mild respiratory COVID-19, Pleasure said.

Over the course of five months in 2020, 18 children and teens were hospitalized at UCSF Benioff Children's Hospital with confirmed COVID-19; the patients tested positive for the virus with either a PCR or rapid antigen test. From this group of pediatric patients, the study authors recruited three teens who underwent neurological evaluations and became the focus for the new case study. 

One patient had a history of unspecified anxiety and depression, and after catching COVID-19 they developed signs of delusion and paranoia. The second patient had a history of unspecified anxiety and motor tics, and following infection they experienced rapid mood shifts, aggression and suicidal thoughts; they also experienced "foggy brain," impaired concentration and difficulty completing homework. The third patient, who had no known psychiatric history, was admitted after exhibiting repetitive behaviors, disordered eating, agitation and insomnia for several days, when they hadn't shown these behaviors previously.

As part of their neurological examinations, each teen underwent a spinal tap, where a sample of CSF is drawn from the lower back. All three patients had elevated antibody levels in their CSF, but only the CSF of patients 1 and 2 carried antibodies against SARS-CoV-2, the virus that causes COVID-19. In those two teens, it's possible the virus itself infiltrated their brains and spinal cords, the study authors noted. "I would suspect that if there is direct viral invasion it is transient, but there is still a lot of uncertainty here," Pleasure noted. 

These same patients also carried neural autoantibodies in their CSF: In mice, the team found that these antibodies latched onto several areas of the brain, including the brain stem; the cerebellum, located at the very back of the brain; the cortex; and the olfactory bulb, which is involved in smell perception. 

The team then used lab-dish experiments to identify the targets the neural antibodies grabbed onto. The researchers flagged a number of potential targets and zoomed in on one in particular: a protein called transcription factor 4 (TCF4). Mutations in the gene for TCF4 can cause a rare neurological disorder called Pitt-Hopkins syndrome, and some studies hint that dysfunctional TCF4 may be involved in schizophrenia, according to a 2021 report in the journal Translational Psychiatry.

These findings hint that the autoantibodies might contribute to a runaway immune response that causes psychiatric symptoms in some COVID-19 patients, but again, the small study cannot prove that the antibodies themselves directly cause disease. It may be that other immune-related factors, apart from the antibodies, drive the emergence of these symptoms. 

"These autoantibodies may be most clinically meaningful as markers of immune dysregulation, but we haven’t found evidence that they are actually causing the patients’ symptoms. There’s certainly more work to be done in this area," co-first author Dr. Christopher Bartley, an adjunct instructor in psychiatry at the UCSF Weill Institute for Neurosciences, said in a statement.

In future studies, "it would … be helpful to examine CSF of children with COVID-19 who did not have neuropsychiatric symptoms," as a point of comparison to those who did, Gombolay said. "However, obtaining CSF from those patients is challenging as CSF has to be obtained by a spinal tap, and a spinal tap is not typically done unless a patient has neurological symptoms."

That said, the team is now collaborating with several groups studying long COVID, who are collecting CSF samples from patients with and without neuropsychiatric symptoms, Pleasure said. "In adults, it is not uncommon to have patients be willing to undergo a spinal tap for research purposes with appropriate informed consent and institutional review." Using these samples, as well as some studies in animal models, the team will work to pinpoint the autoimmune mechanisms behind these troubling neuropsychiatric symptoms, and figure out how autoantibodies fit into that picture. 

Originally published on Live Science.

Six years ago, a teenager from Italy traveled to the U.S. in hopes of finding a diagnosis for her mysterious medical condition, which had caused her to lose the ability to walk and required her to have a breathing tube. Now, researchers have diagnosed the teenager, Claudia Digregorio, and 10 other children with a new form of amyotrophic lateral sclerosis (ALS) that strikes in childhood and progresses more slowly than what is typically seen with this condition.

In addition, the researchers have pinpointed a gene that seems to cause this form of ALS, and they may have also identified a potential treatment for the condition, according to a study describing the findings, published Monday (May 31) in the journal Nature Medicine.

"We hope these results will help doctors recognize this new form of ALS and lead to the development of treatments that will improve the lives of these children and young adults," Dr. Carsten Bönnemann, senior investigator at the National Institute of Neurological Disorders and Stroke (NINDS) and a senior author of the study, said in a statement. "We also hope that our results may provide new clues to understanding and treating other forms of the disease."

Related: 10 things you didn't know about the brain

ALS is a rare disease that causes progressive degeneration and death of the nerve cells that control voluntary muscle movements, such as chewing, walking, talking and breathing, according to the NINDS. Most people with ALS develop symptoms between ages 55 and 75, and the disease usually progresses rapidly, with death occurring in three to five years after diagnosis.

But with the new form of ALS, symptoms appeared much earlier, often around 4 years of age. For many of the 11 patients, problems with walking and spasticity in their lower limbs were the first signs of the disease. By the teenage years, many of the patients, like Digregorio, required a wheelchair for mobility and a tracheostomy tube for breathing support. Before Digregorio left for the U.S., the then 15-year-old met with Pope Francis, who offered prayers for her health, according to a 2015 issue of the NIH Record, a newsletter of the National Institutes of Health.

The researchers found an answer for Digregorio, who was the first patient included in the study. Despite developing symptoms at such an early age, she and the other 10 children showed hallmark signs of ALS on neurological exams, including severely weakened or paralyzed muscles, the researchers said.

"These young patients had many of the upper and lower motor neuron problems that are indicative of ALS," said study lead author Dr. Payam Mohassel, a clinical research fellow at the NIH. (Motor neurons are nerve cells in the brain and spinal cord that send signals that control movement. Upper motor neurons originate in the brain and send signals to the lower motor neurons, which are in the spinal cord.) "What made these cases unique was the early age of onset and the slower progression of symptoms," Mohassel said. "This made us wonder what was underlying this distinct form of ALS."

Using genetic sequencing, the researchers found that these patients had genetic changes in a specific section of a gene called SPLTC1. This gene is involved in the production of fats called sphingolipids, which are particularly abundant in brain tissue. A number of other deadly neurodegenerative diseases, including Nieman Pick disease and Tay-Sachs disease, are also caused by problems with sphingolipid metabolism. 

Further research revealed that the mutation in SPLTC1 increased the levels of sphingolipids. Specifically, the researchers found that the mutation "takes the brake" off of an enzyme involved in the production of sphingolipids, meaning the body keeps churning out these fats without its usual feedback system to tell it when to stop.

The findings mean that restoring this "brake" might treat this type of ALS, the authors said.

In another experiment, the researchers tested a therapy called small interfering RNA, or siRNA, in which small strands of RNA work to "silence" a mutated gene — in this case, SPLTC1. In studies in lab dishes, the therapy worked to restore sphingolipids levels to normal.

"Our ultimate goal is to translate these ideas into effective treatments for our patients who currently have no therapeutic options," Bönnemann said.

Future studies should also look into whether problems with sphingolipid metabolism play a role in other forms of ALS, the authors said.

Originally published on Live Science. 

Many children who develop a rare inflammatory syndrome after COVID-19 see their most serious symptoms clear up by six months, a new study suggests.

Although the study was small, involving fewer than 50 kids with the condition, called multisystem inflammatory syndrome in children (MIS-C), the authors say the results are encouraging.

"These findings can hopefully signal cautious optimism that many of the most severe effects of [MIS-C] appear to resolve within six months," study co-author Dr. Justin Penner, of the Department of Pediatric Infectious Diseases at Great Ormond Street Hospital in London, said in a statement. Still, some children did experience persistent fatigue and difficulty exercising that should be closely monitored, the researchers said.

Related: 14 coronavirus myths busted by science 

MIS-C was first discovered in April 2020, and involves inflammation of multiple organs, such as the heart, lungs, kidneys, brain, skin, eyes and gastrointestinal tract, according to the Centers for Disease Control and Prevention (CDC). Kids with the condition may experience fever, rash, abdominal pain, vomiting or diarrhea, usually after testing positive for COVID-19, and they usually need to be hospitalized. The condition is rare — after about 1 year, a total of 3,742 cases of MIS-C and 35 deaths have been reported in the U.S., according to the CDC; while about 4 million children have tested positive for COVID-19 since the beginning of the pandemic, according to the American Academy of Pediatrics.

The new study, published Monday (May 24) in the journal The Lancet Child & Adolescent Health, is the longest study of MIS-C to date, following children for six months after their hospitalization. The researchers analyzed information from 46 children who were hospitalized with MIS-C at Great Ormond Street Hospital from April to September 2020.

At the time they were hospitalized, all of the children had body-wide inflammation, meaning they had increased levels of inflammatory markers in their blood. The vast majority, 98%, had gastrointestinal symptoms, 52% had neurological symptoms and 33% had heart symptoms.

However at six months, just one child (2%) still had systemic inflammation, two (4%) had heart abnormalities and six (13%) had gastrointestinal symptoms. None of the children died.

What's more, 98% of the patients had returned to school full time (virtual or in-person). 

And scores on a test of muscle strength improved from 53 out of 80 (with higher scores indicating better strength) during hospitalization to 80 out of 80 at 6 months.

About 40% of patients showed subtle abnormalities on specific neurological tests, such as slight problems on tests of coordination, reflexes and eye movement. But these abnormalities didn't translate into "functional impairment," that is, the children didn't have problems with their ability to perform everyday tasks, such as walking, the authors said.

Still, some had trouble exercising, as measured by a test of how far they could walk in 6 minutes. Six months after hospitalization, about 40% of the children scored in the bottom 3% for their age and sex on the walking test. 

But this finding is difficult to interpret because the study did not compare to the walking speed of children who were not hospitalized with MIS-C, the authors said. It's possible that during the pandemic, even healthy children experienced reductions in their exercise ability, given that lockdowns prevent people from exercising normally.

"The levels of fatigue and muscle weakness we found at six months follow-up are concerning and requires close monitoring, but it's difficult to determine whether this finding is caused directly by [MIS-C] or if it's a result of the disruption in children’s lives that the COVID-19 pandemic has caused on a wider scale," study co-author Dr. Karyn Moshal, of Great Ormond Street Hospital's Department of Pediatric Infectious Diseases, said in a statement. 

The new study also cannot rule out the possibility that additional long-term effects might show up in the children more than six months after hospitalization (such as kidney disease, which sometimes appears more than six months after a severe illness), and so it is important to continue follow-up studies on MIS-C patients, the authors said.

Originally published on Live Science.  

Kinetic sand has all the appeal of that coarse beachy material without the gets-everywhere part. This moldable sandy substitute retains a granular texture but doesn't stick to hands or surfaces. It's soft and shapes easily, maintaining its character no matter what structure or creature is created. It gives kids the room to imagine and invent, again and again. And, unlike modeling clay, this malleable material doesn't dry out. We've assembled the best variety of color and package options to fill playtime with tons of fun. 

More than a grain of fun

Kinetic sand is a grainy alternative to regular sand, sans the mess. It has the consistency of wet sand, molding, and shaping, but without the residue. Our first choice when it comes to this shapeable modeling masterpiece is the National Geographic ultimate play sand. With 6 pounds of squishy sand in three colors (blue, purple, and natural), this set is brimming with buildable potential. Kids can use their imagination, and six included molds to shape their creations.

To get the most out of the kinetic sand experience, additional toys and tools can help. The USA Toyz 23-pack mini sandbox toys set includes a variety of molds and sculpting tools so kids can fashion their most imaginative designs.