Polio-like illness causing paralysis in children reaches the Carolinas

(CNN) — A polio-like illness that can cause paralysis in children is now here in the Carolinas.

CNN learned that both North Carolina and South Carolina are among 30 states with confirmed cases of acute flaccid myelitis.

Acute flaccid myelitis, or AFM, is rare, but the Centers for Disease Control said it has become more common recently. The agency said it is very concerned about it.

Symptoms of AFM are similar to polio. It affects the nervous system and can cause paralysis. It affects mostly children.

CNN has reported that this year, more than half of all U.S. states have had confirmed or possible cases, including North and South Carolina.

Among the concerns the CDC has are that the agency does not know the cause of AFM, why there has been an increase in cases since 2014, or the long-term effects of the illness.

The CDC is actively investigating the cases and working with healthcare providers as well as state and local health departments to spread the word about AFM.

About 90 percent of the cases are children who have suffered muscle weakness or paralysis. Most kids recover.