The California Department of Public Health (CDPH) requests healthcare providers and local health departments to be vigilant for acute flaccid myelitis (AFM), which typically presents with sudden limb weakness in children that can lead to permanent paralysis. Clinicians should consider the diagnosis of AFM in patients with acute onset of flaccid weakness to ensure optimal care.
During periodic surges in AFM before the COVID-19 pandemic, enterovirus D68 (EV-D68) was the most common enterovirus detected among AFM cases, typically in late summer and early fall when enteroviruses tend to circulate. Historically, increases in EV-D68 respiratory disease, including severe disease requiring hospitalization especially in children, have preceded these surges in AFM by several weeks. In August 2022, a similar increase in EV-D68 respiratory disease was detected in sentinel surveillance sites in the United States, including California, thereby warranting increased vigilance for AFM. From January 1, 2022 through September 14, 2022, CDPH has received 11 reports of suspected AFM in persons from California; six have been classified by the Centers for Disease Control and Prevention (CDC) as confirmed cases of AFM. Please see CDC's recent HAN "Severe Respiratory Illnesses Associated with Rhinoviruses and/or Enteroviruses Including EVD68" for more information.
Importantly, with the identification of a paralytic polio case in an unvaccinated person in New York in July 2022, clinicians should consider polio in patients with suspected AFM who are not fully vaccinated against polio AND have either traveled to or had contact with travelers from areas where polio is circulating.
For AFM cases, the CDPH VRDL regularly tests cases for SARS-CoV-2, enterovirus (including typing to identify poliovirus), rhinovirus and adenovirus and conditionally for West Nile, St. Louis encephalitis, Zika, dengue, and chikungunya viruses. The timing of results typically precludes their guiding clinical management.
For questions about shipping specimens to the VRDL, call 510-307-8585. For AFM assistance or consultation, call CDPH Immunization Branch at 510-620-3737 or email AFM@cdph.ca.gov.