After two years of significantly low levels, strep infections in the US have surged again this season, according to a new analysis.
In February, the share of health care visits for strep throat or a related diagnosis was nearly 30% higher than during the previous peak in 2017. And preliminary data for early March shows a continued upward trend, according to the Epic Health Research Network. The findings are based on electronic health records from thousands of clinics and hospitals, representing more than 100 million people across the country.
Group A Streptococcus bacteria can cause many types of infections. Some, like strep throat and scarlet fever, can be relatively mild and are usually treated with antibiotics. But in December, the US Centers for Disease Control and Prevention said it was investigating an apparent increase in invasive group A strep infections, which can cause more rare and serious infections. The US also has an ongoing shortage of liquid amoxicillin, the antibiotic most often used to treat group A strep infections.
Anyone can get strep throat, but it is most common among children ages 5 to 15, according to the CDC. The season typically runs from December through April, with a peak in February.
According to the new analysis, diagnosis is typically most common among children ages 4 to 8. For this group, the share of health care visits for strep usually stays below 5% when the season peaks in February – but this year, that spiked to more than 8%.
All age groups followed similar trends, and there were increases across all races, geographic regions and socioeconomic status.
Prevention measures related to the Covid-19 pandemic probably helped keep strep levels consistently low for the past two years.
“It is too early to definitively characterize this season since we are still in the middle of it,” the CDC told CNN. And although invasive group A strep activity has increased, “infections remain rare, especially in children.”