Dear Partners:

The Centers for Disease Control and Prevention (CDC) has released a COCA Clinical Reminder, providing an update of the 2014-2015 investigation of acute flaccid myelitis (AFM) in U.S. children and a revised case definition. CDC recommends that clinicians remain vigilant for patients presenting with symptoms of AFM and report cases to their health department. Learn more.

Update and Background

From August 2014 to July 2015, CDC has verified reports of 120 children in 34 states who developed AFM that met CDC’s outbreak case definition. CDC continues to receive sporadic reports of cases, but despite extensive testing and investigation a cause has still not been determined. It is unclear if an increase in AFM could occur again this year, as seen from August to October 2014. CDC continues to collaborate with partners nationally to investigate reported cases, risk factors, and possible causes of this condition.

Revised Case Definition

  1. Acute onset of focal limb weakness, AND
  2. An MRI showing a spinal cord lesion largely restricted to gray matter, OR cerebrospinal fluid (CSF) with pleocytosis,  AND
  3. without another apparent cause (such as, but not limited to, Guillain-Barrè syndrome, transverse myelitis, trauma, or toxic neuropathy).

In June 2015, the Council of State and Territorial Epidemiologists (CSTE) adopted a standardized case definition for AFM ( that removes the case age limit from the CDC outbreak definition and adds “CSF showing pleocytosis (white blood cell count >5 cells/mm3)” as a criterion for identifying a probable AFM case.

How you can help

The purpose of this email is to re-emphasize the importance of continued vigilance for cases of AFM among all age groups, with the aim of increasing case reporting from neurologists, radiologists/neuroradiologists, neuroscience professionals, and other healthcare professionals nationwide.

  • Forward this email to your colleagues, including infectious disease specialists, intensive care physicians, pediatricians, neurologists, radiologists/neuroradiologists, infection preventionists, and primary care providers, as well as to emergency departments and microbiology laboratories.