Earlier this month, the CDC said hospitals through July and August had detected the largest number of infections caused by enterovirus D68 since 2018.
A CDC spokesperson told The New York Times that 84 cases had been confirmed from March through Aug. 4. Children's hospitals are currently experiencing capacity issues amid an influx of children with respiratory diseases, including enterovirus, though its unclear whether patients have EV-D68 specifically.
Here are four things to know about EV-D68:
1. EV-D68 is one of more than 100 non-polio enteroviruses, which are thought to be very common, according to the CDC. Most enterovirus infections cause no symptoms or only mild, cold-like symptoms. Infections can happen year-round, though are more likely in late summer and fall.
2. In rare cases, EV-D68 may cause acute flaccid myelitis among children. AFM is a rare polio-like complication "that typically presents with sudden limb weakness." Children with asthma may have a higher risk for severe symptoms from an EV-D68 infection.
"In most people, [EV-D68] is an acute viral illness that come and goes without incident; in the very select few, it can cause neurologic symptoms like this acute flaccid myelitis," Amy Arrington, MD, PhD, medical director of the special isolation unit and section chief of global biological preparedness at Texas Children's Hospital in Houston, told the Times.
3. The virus was first identified in 1962, though the CDC has only tracked it closely since 2014, when it caused a nationwide outbreak. From mid-August of that year through Jan. 15, 2015, 1,395 cases of EV-D68 were confirmed in the U.S. Almost all of the confirmed cases were among children, many of whom had a history of asthma or wheezing. The U.S. saw subsequent peaks in the fall of 2016 and 2018. In 2020, there appeared to be "relatively lower circulation," likely due to COVID-19 mitigation measures.
4. The CDC in its Sept. 12 alert said so far this year, there has not been an increase in reported cases of AFM, though a rise in EV-D68 cases usually precede AFM reports, "indicating that increased vigilance" will be important over the next few weeks. During the 2014 EV-D68 outbreak, there were 120 confirmed cases of AFM.
Click here to read more about the virus and AFM.