Acute Flaccid Myelitis Surveillance: A Signal Through the Noise

* Abbreviations: AFM — : acute flaccid myelitis CDC — : Centers for Disease Control and Prevention CSF — : cerebrospinal fluid Ayers et al1, in the current issue of Pediatrics , provide comprehensive surveillance data for the polio-like illness acute flaccid myelitis (AFM) in the United States from January 1, 2015, to December 31, 2017. Importantly, in this study, they found that among the 193 children meeting the confirmed AFM case definition during the 3-year period, 143 instances (74%) occurred in 2016, fitting within the larger epidemiological context of a biennial pattern of AFM outbreaks in the US documented from 2014 to 2018 (Fig 1).2 Additionally, approximately two-thirds of the 2016 cases occurred in August to October, mirroring the summer-to-fall seasonality of the 20143 and 2018 outbreaks.4 Thirty-six percent of respiratory specimens and 19% of stool and rectal specimens tested at the Centers for Disease Control and Prevention (CDC) were positive for an enterovirus or rhinovirus, but viruses were rarely detected in cerebrospinal fluid (CSF) ( n = 1) or blood ( n = 2). Notably, 69% (22 out of 32) of enteroviruses and rhinoviruses from respiratory specimens were typed as enterovirus-D68; no other picornavirus was detected in more than 3 patients. The authors conclude that the composite nationwide 2015 to 2017 AFM surveillance data suggest a viral etiology but that it … Address correspondence to Samuel R. Dominguez, MD, PhD, Children’s Hospital Colorado, 13123 E 16th Ave, B055, Aurora, CO 80045. E-mail: samuel.dominguez{at}childrenscolorado.org