Health officials are warning of a possible increase in cases of a rare, polio-like condition among children.
On Friday, the Centers for Disease Control and Prevention issued a health alert detailing a rise in severe respiratory illness this fall that can lead to a condition called acute flaccid myelitis.
Acute flaccid myelitis, or AFM, is a severe neurological condition that affects the nervous system — specifically the spinal cord — and causes loss of reflexes and a sudden unexplained weakness or paralysis of the arms or legs. According to the CDC, more than 90% of cases occur in young children.
The virus is believed to be caused by enterovirus D68. Some enteroviruses are very common and cause only mild illness. While common cold symptoms are typical, the enteroviruses can sometimes cause more dangerous symptoms in younger immune systems.
The CDC previously saw an increase in AFM in 2014, 2016 and 2018.
"We really thought this was going to happen in 2020, because we had the last spike in 2018," Dr. Sarah Hopkins, a pediatric neurologist at Children's Hospital of Philadelphia, told NBC News. "But then with mask-wearing and social distancing and all those things that limit the spread of a respiratory virus, we didn't have that expected spike."
Dr. Benjamin Greenberg, a neurologist at UT Southwestern's O'Donnell Brain Institute, added that cases will likely increase again with school back in session, specifically with the return to in-person learning.
"We have a group of kids now who've never seen the virus, because they weren't having school exposures. So we think the at-risk population is bigger than in 2020," he told the outlet.
Since there is no vaccine or antiviral medicine for enterovirus D68 or AFM, health professionals will offer typical treatments. The CDC advises standard practices to reduce the spread of germs: washing hands with soap and water, covering your cough or sneeze, and staying up-to-date on recommended vaccines.
"The warning sign is often, a child who's recovering from a routine illness and then the recovery stops looking like what you would expect — they're now getting worse again, and especially if they become weak," Dr. Matt Elrick, assistant professor of neurology at the Kennedy Krieger Institute who specializes in AFM, told ABC News.
The CDC also stresses that while rates of AFM are increasing, it's still an incredibly rare disease.
Cases of AFM typically start in the late summer to early fall. In 2022, as of Sept. 2, there have been 13 confirmed cases across nine states.
"This is exceptionally rare even during an outbreak so it's not something that should necessarily keep everyone up at night," Elrick continued. "But if your child has an illness and was recovering and is now getting worse again, or not behaving in the way that you might expect the normal recovery from illness to be, that's a good reason to go see the pediatrician and sort out what's going on."
The CDC recommends contacting a healthcare provider immediately if you or your child has trouble breathing or sudden limb weakness.