Federal health officials have confirmed 134 cases of acute flaccid myelitis (AFM) and say they believe cases have peaked.
The confirmed cases span 33 states and are among 299 potential cases reported to the Centers for Disease Control and Prevention (CDC) this year.
AFM is defined as:
- acute onset of flaccid limb weakness and
- MRI showing spinal cord lesion largely restricted to gray matter spanning one or more vertebral segments (confirmed case) or cerebrospinal fluid with pleocytosis (probable case).
Most cases have been among children who have had a fever or respiratory illness in the weeks leading up to their limb weakness. However, the CDC has not been able to pinpoint a cause of AFM and recently created a task force to investigate. The group will release its first report on Thursday.
AFM cases have spiked every other year since 2014. Case counts this year have been on par with 2016 and 2014, which saw 149 and 120 confirmed cases, respectively. As in previous years, they began to decline in November.
“Although fewer cases are expected in coming months, CDC and partners continue to carefully study AFM to gain new understanding of the condition so that we can better diagnose, treat, and prevent it in the future,” the CDC said in a news release.
Physicians should be vigilant for patients with limb weakness, which also may present with facial droop or difficulty swallowing. They should ask whether patients recently experienced respiratory or gastrointestinal illness. Those who suspect a patient has AFM should perform a workup, including MRI, spinal tap and collection of respiratory, stool, serum and spinal fluid samples for testing, and report suspected cases to their state or local health department.