Clinical Action : March 24

CDC Updates Specimen Collection, Shipping, and Testing Guidance for Suspected Acute Flaccid Myelitis (AFM) Cases

Acute Flaccid Myelitis in the United States

CDC continues to receive information about cases of AFM. So far in 2017, CDC has received information for one confirmed case of AFM. From January 1, 2016 through December 31, 2016, CDC received information for 136 persons from 37 states who met the Council of State and Territorial Epidemiologists (CSTE) case definition for confirmed AFM. Despite extensive pathogen-specific testing of many specimens since 2014, CDC and others have not identified an etiology for the AFM cases. Therefore, CDC will no longer perform clinical diagnostics for enteroviruses or metagenomic sequencing on specimens collected from suspect cases of AFM. Instead, CDC has expanded the search for potential causes of acute flaccid myelitis (AFM) by broadening laboratory approaches that test for potential infectious and noninfectious causes, including possibly immune-mediated mechanisms.

Updated Laboratory Guidance

CDC continues to intensify its efforts to understand the cause and risk factors of AFM and has changed its collection, storage, and shipping guidance for specimens from AFM cases. Changes can be found on CDC's website. 

In addition, please see the printable job aid PDF on CDC’s website.

Pathogen-specific testing should continue at hospital or state public health laboratories and may include cerebrospinal fluid, sera or whole blood, stool, and respiratory specimens. CDC will prioritize testing of sterile site specimens (i.e., cerebrospinal fluid, blood) using these new protocols to optimize yield of an etiologic agent or possible mechanism for AFM. Non-sterile site specimens, such as respiratory samples, will not be routinely tested at CDC. Stool or fecal specimens should be sent to CDC to rule out the presence of poliovirus. Specimens that are positive for enteroviruses/rhinoviruses at external laboratories may be sent to CDC for typing.

The new testing performed at CDC uses assays that are not CLIA-approved and are not intended for clinical diagnosis; therefore, CDC will not be able to provide specific test results for individual samples. CDC will rapidly disseminated results that indicate a possible cause of AFM to state and local health departments.

Resources and More Information

• Printable Job Aid PDF—How to Send Information about a Suspected AFM case to the Health Department:https://www.cdc.gov/acute-flaccid-myelitis/downloads/job-aid-for-clinicians.pdf
• Specimen collection and submission: http://www.cdc.gov/acute-flaccid-myelitis/hcp/specimens.html
• Specimen collection instructions: http://www.cdc.gov/acute-flaccid-myelitis/hcp/instructions.html
• Resources and References: https://www.cdc.gov/acute-flaccid-myelitis/downloads/job-aid-for-clinicians.pdf
• AFM in the United States: http://www.cdc.gov/acute-flaccid-myelitis/afm-surveillance.html
• Data collection and reporting: http://www.cdc.gov/acute-flaccid-myelitis/hcp/data.html