The CDC is not ruling out any possible triggers-from infections to toxins, autoimmune reactions to bug bites.
"We know this can be frightening for parents", said Dr. NancyMessonnier, director of the CDC's National Center for Immunization and Respiratory Diseases.
Because officials don't know the cause of AFM, they can't recommend a specific way to prevent it.
Physicians first began noticing an increase in AFM patients in 2014, with roughly 120 confirmed cases. "Most of the cases that CDC has learned about have been in children", said the CDC.
Infection with many different viruses can cause neurological complications. It is important that tests are done as soon as possible after someone develops symptoms.
Some children may have mild symptoms, but AFM doesn't just sneak up on its victims.More news: Ariana Grande Breaks Silence on Pete Davidson Split
Fox 2/KPLR 11's Dan Gray talked to an infectious disease specialist who said the disease isn't new but should be considered a growing health concern. Some with AFM will feel weakness in their arms or legs, a loss of muscle tone or slower reflexes. Although there is no definitive diagnosis, doctors can identify AFM from a combination of symptoms and an MRI scan, which can reveal spine inflammation.
"This is a mystery so far", the CDC's Dr. Nancy Messonnier said in a call Tuesday with reporters.
Health officials said five kids in Maryland are believed to have contracted a virus this fall that has symptoms similar to polio.
This year's outbreak marks the third wave of acute flaccid myelitis (AFM) to hit the United States since 2014, and this wave is on track to be the worst yet, experts say. Ninety percent of the cases have been in children, she says.
Faircloth said she wants other parents to be aware.
"AFM is a very rare and serious condition", Messonnier said, urging parents to take preventive steps such as encouraging hand washing, ensuring that children receive recommended vaccinations, and making sure they wear insect repellent.More news: How to quickly check if your Facebook account was hacked
"The cases are from all over the state", Ehresmann said. That suggests to him the disease can completely wipe out the nerves. One death of a child diagnosed with AFM occurred in 2017.
But both Glatter and Ehresmann were quick to reiterate that AFM is very rare.
Officials with Children's Healthcare of Atlanta at Scottish Rite Hospital told WVLT News that Hill was receiving treatment in an area of the hospital where patients diagnosed with AFM would be cared for. So far, a common cause linking these illnesses has not been found.
Despite extensive laboratory and other testing, CDC has not been able to find the cause for the majority of the cases. "Unfortunately, there are no real treatments that have been proven to work, but early rehabilitation has been shown to help". But that bug - enterovirus D68 - could not be definitively linked to the illnesses.
There's no vaccine that can protect against AFM-causing enteroviruses. The U.S. has had 386 confirmed cases since August 2014. That appears to indicate an every-other-year pattern.
In some cases children have recovered, but in others the paralysis has lingered.More news: Student's cookie recipe may have included grandparent's ashes
That's up from 22 people who were said to have it in 2015. The CDC said the average age of patients nationwide is four years old.