'It's real, and it's happening': Antibiotic resistance in kids is rising around the world, massive study finds

In the past 20 years, an increasing number of bacterial infections caught by children have been resistant to antibiotics, a new study finds.

The research, published in July in the journal JAMA Pediatrics, looked back at the past two decades, as well as looked forward, to predict how resistance rates might change in the decade to come. By 2035, some critical antibiotics will be met with "steep increases" in resistance among common bacteria, such as Acinetobacter baumannii and Klebsiella, the analysis found.

Antibiotic resistance contributed to 840,000 deaths among children under 5 in 2021, global estimates suggest, so if resistance continues to increase, that number could grow.

"These forecasts are warning scenarios, not inevitable outcomes," said study co-author Dr. Yanhong Jessika Hu, a clinical epidemiologist and public health researcher at Murdoch Children's Research Institute (MCRI) in Australia. "The projections broadly assume that historical patterns continue without a major change in direction," Hu told Live Science in an email.

If significant action is taken, that trajectory could be altered, she said.

"Resistance increased across all regions"

Antibiotic resistance is sometimes called "a silent pandemic," as it poses a formidable threat without stirring as much concern as other health crises, such as viral outbreaks. Resistance has gained attention in recent years, but the data on how it has affected children is patchy, said study co-author Dr. Penelope Bryant, a clinician-researcher at MCRI, Royal Children's Hospital Melbourne, and the University of Melbourne.

"It's perceived as being a lesser problem in children," Bryant told Live Science. "It's not a theoretical problem; it's real, and it's happening. But I think the visibility is just substantially less than in adults."

That's partly because many resistance-tracking efforts combine adult and pediatric data, and the adult data ends up obscuring trends in children, Hu said. "Adult findings cannot simply be applied to children because children have different infection patterns, antibiotic exposure and treatment options," she noted.

Meanwhile, studies aimed only at children tend to vary in the age groups and clinical settings they include, making direct comparisons difficult, Hu said. This lack of granularity hinders efforts to counter resistant infections in children through changes in policy or clinical protocols. Children also have fewer antibiotic options than adults do at baseline, which makes preserving those options even more important, Bryant added.

To help fill the gap, the researchers turned to the Antimicrobial Testing Leadership and Surveillance database, which contains clinical samples from children and teens ages 0 to 18 across 82 countries. These bacterial samples were collected between 2004 and 2022 from a variety of medical settings, including hospital wards, intensive care units and outpatient clinics. The included countries ranged from high-income, such as the U.K. and the U.S., to low-income, such as Malawi and Uganda.

The analysis included over 106,000 bacterial samples and assessed which antibiotics these germs were resistant to. The antibiotics were grouped based on the World Health Organization's Access, Watch, Reserve (AWaRe) system: "Access" antibiotics target few bacteria and are recommended as the first choice for most bacterial infections, "Watch" antibiotics have broader effects and should be used selectively for more-resistant infections, and "Reserve" antibiotics are considered last-resort options to use when all alternatives have failed.

"Resistance increased across all regions, showing that this is not only a problem in lower-income countries," Hu said. "However, the highest resistance levels and some of the steepest increases were seen in lower-resource settings."

A wake-up call

Part of the analysis zoomed in on eight bacteria that are considered "critical" or "high" priority by the WHO, meaning they impose a particularly high healthcare burden due to their resistance. Across these germs, resistance rates were similar across high- and low-income countries in 2004, but those trends diverged by 2022.

Overall, resistance to Access antibiotics declined across the study period, but that improvement wasn't the same across all settings. In high-resource countries, resistance to Access drugs fell from 48% to 29% among the eight bacteria, while it rose slightly — from 44% to 47% — in low-income settings. These percentages correspond to the number of bacterial samples from each year that showed resistance to at least one Access drug.

The decline seen in some countries is "almost certainly because of the large investment that high-income countries have put into controlling MRSA," Bryant said, referencing methicillin-resistant Staphylococcus aureus. MRSA can cause painful skin infections as well as life-threatening complications, like sepsis.

Modeling future trends, the team predicts that resistance to Access antibiotics will stabilize or decline across most regions by 2035. However, resistance against Watch antibiotics rose between 2004 and 2022 and is projected to continue increasing. Among the eight critical and high-priority bacteria, it rose from 14% to 24% in high-income countries and from 16% to 48% in low-income nations.

Resistance to Reserve drugs also increased among these germs, rising from 9% to 25% in high-income countries and from 4% to 37% in low-income ones.

While the model predicted "steep increases" in Watch resistance, it projected slower increases in Reserve resistance over the next decade, by comparison. These trends were driven largely by increases in low-income settings, but high-income settings were not spared.

"With low-income countries, the problem is amplified because of poor sanitation and because of unregulated access to antibiotics," Bryant noted. Easy access to over-the-counter antibiotics makes it more likely for the medicines to be misused, which ultimately pressures more bacteria to evolve resistance.

This analysis gives a snapshot of how antibiotic resistance is affecting kids now and how it might do so in the future. However, the data it's based on has some limitations. For instance, the samples collected from each country aren't necessarily representative of the entire nation; they came from only certain participating medical centers and each country contributed different numbers and types of samples. So "the results should therefore not be interpreted as precise national prevalence estimates," Hu cautioned.

"But it's the first large dataset, really, to look specifically at children," Bryant said. And "it gives us an idea that things are getting worse."

The team has made their analysis freely available to other researchers on the website AMR in Kids, where "AMR" stands for antimicrobial resistance. Future steps include surveying resistant infections in children in a more representative way, as well as modeling how different intervention strategies could help drive down the rates.

"I'm hopeful that this is a little bit of a sort of wake-up call around children, that it really isn't a problem just in adults," Bryant said.