CDC officials say they haven’t found the cause of the illness, though a virus is suspected.
There is no specific treatment for the disorder, whose confirmed cases have seen a significant increase this year.
About 90 percent of the cases are children who have suffered muscle weakness or paralysis, including in the face, neck, back or limbs. The symptoms tend to occur about a week after they had a fever and respiratory illness.
Parents are urged to seek medical care if their child shows symptoms of the disease, and health providers can relay reports to public health authorities.