A rare condition causing weakness in the arms or legs — and sometimes paralysis — has been confirmed in 62 children so far this year, the Centers for Disease Control and Prevention said Tuesday.
One child has died of the condition, called acute flaccid myelitis, or AFM.
At least 65 more cases are under investigation, said Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases. So far, a common cause linking these illnesses has not been found.
“There is a lot we don’t know about AFM,” Messonnier said during a teleconference for reporters. “I am frustrated that despite all of our efforts, we haven’t been able to identify the cause of this mystery illness.”
The average age of the children is about 4, she said, and 90 percent of cases the CDC has been studying since 2014 have involved patients 18 or younger.
Messonnier said scientists don’t fully understand the long-term consequences of the illness: “We know that some patients diagnosed with AFM have recovered quickly and some continue to have paralysis and require ongoing care.”
Since the condition was first recognized by CDC in 2014, the agency has confirmed 386 cases through Oct. 16, mostly in children. AFM appears to be seasonal, occurring mostly in the late summer and fall, but appears in greater numbers every other year.