U.S. health officials on Tuesday reported a jump in cases of a rare paralyzing illness in children, and said it seems to be following an every-other-year pattern.
At least 62 cases have been confirmed in 22 states this year, and at least 65 additional illnesses in those states are being investigated, according to the Centers for Disease Control and Prevention. Similar waves of the same illness occurred in 2014 and 2016.
CDC officials say they haven’t found the cause. Some possible suspects, such as polio and West Nile virus, have been ruled out. Another kind of virus is suspected, but it’s been found in only some of the cases.
“This is a mystery so far,” the CDC’s Dr. Nancy Messonnier said in a call Tuesday with reporters.
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.