Childhood AFM Paralysis Cases Tend To Begin In Late Summer, CDC Warns Doctors To Be Vigilant

Doctors should be prepared to quickly recognize and treat new cases of acute flaccid myelitis (AFM), which is a polio-like illness that typically begins to result in childhood paralysis cases in the late summer, according to federal officials.

The U.S. Centers for Disease Control and Prevention (CDC) issued a press release on July 9, urging doctors to prepare for the upcoming summer/fall acute flaccid myelitis (AFM) “season” and focus on recognizing potential paralysis cases quickly.

AFM is a serious, but rare illness affecting children that often begins with respiratory symptoms, but quickly leads to muscle weakness and paralysis of the limbs. It affects the nervous system, especially the spinal cord, resulting in polio-like paralysis.

In 2018, there were nearly 300 confirmed cases of AFM across 41 states. Investigators still struggle to find a cause for the illness.

The CDC update calls on doctors to focus on quickly recognizing symptoms of AFM and report suspected cases to the health department rapidly. This step can be crucial to providing needed medical care and rehabilitation for affected patients.

The agency began tracking AFM in 2014, which involvd an outbreak of 120 childhood paralysis cases. Another outbreak occurred in 2016, with 149 cases. Then the 2018 outbreak affected 233 patients. So far, 48 states have experienced cases of AFM.

The illness follows a seasonal biennial pattern, which means the cases spike in August and October every other year. Most AFM patients are children who were healthy but had respiratory symptoms or fever consistent with a viral infection less than a week before experiencing limb weakness. AFM can progress quickly and may require urgent medical intervention.

Researchers initially speculated the cause of AFM was enterovirus D68. Further analyses detected enteroviruses and rhinoviruses in about half of respiratory and stool samples. In the 74 cases where cerebral spinal fluid was taken, only two were positive for EV-71 and EV-D68.

Despite the evidence to suggest one of these viruses alone may be the cause, researchers do believe viruses, including enterovirus and rhinovirus, play a role in the onset of the illness but the virus itself may resolve quickly before paralysis begins. However, all specimens tested negative for poliovirus.

Despite the similarities between polio and AFM, researchers are sure the illness is not polio.

“CDC continues to pursue the definitive cause and mechanisms that define this disease and we sincerely appreciate the important contributions of the AFM Task Force in helping us get closer to critical answers,” said CDC Director Robert Redfield. “I urge physicians to look for symptoms and report suspected cases so that we can accelerate efforts to address this serious illness.”