Dangerous strep infection surging in the UK may be spreading in US

illustration of group A Streptococcus bacteria, depicted in green on a red background that represents body tissue
The bacteria that cause strep throat can sometimes trigger more-severe, potentially deadly infections. (Image credit: KATERYNA KON/SCIENCE PHOTO LIBRARY via Getty Images)

As U.K. health officials grapple with an ongoing surge of "invasive" strep infections in children, the Centers for Disease Control and Prevention (CDC) is investigating whether U.S. children are experiencing a similar uptick in infections. 

According to the agency's website (opens in new tab), "CDC is looking into a possible increase in invasive group A strep (iGAS) infections among children in the United States." These severe infections are caused by Group A Streptococcus bacteria, the same bugs behind strep throat, an infection of the throat and tonsils; and scarlet fever, which causes a red, sandpapery skin rash. 

Compared with these relatively mild ailments, invasive strep A infections occur when the bacteria spread to the blood, lungs or muscles, and can lead to life-threatening complications, according to the CDC. For example, the infections can trigger the "flesh-eating disease" necrotizing fasciitis, in which tissues rapidly die due to aggressive inflammation, and streptococcal toxic shock syndrome, a condition marked by a flood of inflammatory molecules, a dangerous drop in blood pressure and widespread organ damage.

In the U.K., the number of reported iGAS cases is higher than expected for this time of year, particularly among children, the U.K. Health Security Agency reported (opens in new tab) Dec. 15. So far in the U.K., 213 children have developed an invasive infection, 111 of whom were 1 to 4 years old. Sixteen children have died of iGAS infections so far this season in the U.K.

Related: Why flesh-eating bacteria can look like the flu

Other European countries — including France, Ireland, the Netherlands and Sweden — have reported similar infection rates among young children, the World Health Organization said (opens in new tab).

As of Dec. 5, the CDC hadn't "heard of any notable increase" in iGAS cases in the U.S.,  Barbara Mahon, acting director of the agency's proposed Coronavirus and Other Respiratory Viruses Division, said at a news conference (opens in new tab). However, since then, several children's hospitals in Arizona, Colorado, Texas and Washington have reported higher-than-average numbers of cases this season compared with the same time in past years, CNBC reported (opens in new tab).

As the CDC investigates these reports, the agency is encouraging children's caregivers to make sure kids are up to date on flu and chickenpox vaccinations, "since getting these infections can increase risk for getting an iGAS infection." The CDC also recommends becoming familiar with the initial signs of necrotizing fasciitis and streptococcal toxic shock syndrome: 

Necrotizing fasciitis: These symptoms typically arise after an injury or surgery, as the bacteria most often enter the body through broken skin. 

  • A red, warm or swollen area of skin that spreads quickly
  • Severe pain, including pain beyond the area of the skin that is red, warm or swollen
  • Fever

Streptococcal toxic shock syndrome: After the initial symptoms below start, it usually takes about 24 to 48 hours for low blood pressure to develop. Once this happens, much more serious symptoms arise, such as tachycardia (faster than normal heart rate), tachypnea (rapid breathing) and signs of organ malfunction. 

  • Fever and chills
  • Muscle aches
  • Nausea and vomiting
  • Hypotension (low blood pressure)

Caregivers should "seek medical care quickly if they think their child has one of these infections," the CDC states. Treatment involves antibiotics as well as surgery to remove infected tissues and supportive care, such as fluids, as needed.

Nicoletta Lanese
News Editor, Health

Nicoletta Lanese is a news editor on Live Science's health desk. She first joined the publication in 2019 as a staff writer. She holds degrees in neuroscience and dance from the University of Florida and a graduate certificate in science communication from the University of California, Santa Cruz. Her work has appeared in The Scientist Magazine, Science News, The San Jose Mercury News and Mongabay, among other outlets.