Mystery Illness Causing Paralysis in Children Baffles DoctorsFederal and state health officials are baffled by a mysterious and rare illness that seems to target children, causing paralysis. As of Tuesday, 62 cases of what doctors are calling acute flaccid myelitis have been confirmed in 22 states. Sixty-five suspected cases are being investigated. "There is a lot we don't know about AFM and I am frustrated that despite all of our efforts, we haven't been able to identify the cause of this mystery illness," Nancy Messonnier, a top official at the Centers for Disease Control, said Tuesday. What is known about the illness is that more than 90 percent of the confirmed cases are in children 18 years old or younger. The average age of patients is 4. Victims generally suffer from muscle weakness and some paralysis of the face, neck, back, arms and legs. The paralysis sets in about a week after the children have come down with fever and respiratory illness. There is no specific treatment, and most of the victims recover. But the long-term effects are still unknown. Messonnier called it a "pretty dramatic disease." Health experts have ruled out some causes, including poliovirus and West Nile virus. But what is particularly confounding doctors is that the number of cases spikes only every other year — with larger numbers in 2014, 2016 and this year — and fewer cases in 2015 and 2017. Parents are urged to have their children take basic precautions, such as washing hands and using insect spray to ward off mosquito bites. Doctors are also urging that vaccines be kept up to date. Any child experiencing weakness or loss of muscle tone in the arms and legs should be examined immediately.