Call for Cases: Acute Flaccid Myelitis – 2018

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Indiana Health Alert Network Advisory — October 17, 2017

Acute flaccid myelitis (AFM) is a condition characterized by acute onset of flaccid limb weakness and magnetic resonance imaging (MRI) showing lesions in the gray matter of the spinal cord. AFM has been investigated by health departments and the Centers for Disease Control and Prevention (CDC) since 2014. Surveillance has shown that AFM cases generally peak in August through October. A biennial pattern has been observed, with the majority of cases reported in 2014 and 2016, and smaller numbers reported in 2015 and 2017. As of October 16, CDC has confirmed 62 cases of AFM in 22 states during 2018. One confirmed AFM case has been reported in Indiana in 2018. Clinicians are encouraged to be aware of the symptoms of AFM, promptly report suspected AFM cases, and collect appropriate specimens for laboratory testing.

AFM appears to start with a prodromal respiratory or gastrointestinal illness about one week before limb weakness onset. Pain in the neck or back often directly precedes weakness in one or more limbs, and cranial nerve findings such as slurred speech, difficulty swallowing, and eyelid or facial droop may occur. On exam, the weak limb(s) displays poor tone and diminished reflexes. Cerebrospinal fluid may show a lymphocytic pleocytosis and elevated protein. MRI findings in AFM cases include lesions in the central, or gray matter, of the spinal cord. The long-term prognosis of patients with AFM is unknown; patients have exhibited a range of outcomes with some regaining full function, some regaining partial function, and some showing minimal to no improvement. There is no specific recommended treatment for AFM, but CDC has issued interim considerations for the clinical management of patients with AFM.

Since AFM is a relatively new condition, information on all patients is needed to better understand the spectrum of illness and all possible causes, risk factors, and outcomes. The Indiana State Department of Health (ISDH) requests clinicians to submit information about patients who meet the clinical criteria for AFM (sudden onset of flaccid limb weakness), regardless of laboratory results or MRI findings, to the ISDH including: CDC’s AFM patient summary form, admission and discharge notes, neurology and infectious disease consult notes, MRI reports, MRI images, vaccination history, and laboratory test results. The patient summary form and requested records may be submitted to the ISDH Epidemiology Resource Center by fax at 317-234-2812.

The case definition for AFM includes people of all ages to enable collection of information on the full spectrum of the condition in both children and adults. For more information about the case definition for AFM, please see

Possible causes of AFM may include viruses, including enteroviruses, West Nile virus, other flaviviruses, and adenoviruses; environmental toxins; and genetic disorders. The CDC continues to evaluate all possible etiologies and advises clinicians to collect specimens from patients suspected of having AFM as early as possible in the course of illness, preferably on the day of onset of limb weakness. Early specimen collection has the best chance to yield etiologies for AFM. Specimens to collect include:

  • CSF;
  • Serum;
  • Stool; and
  • Nasopharyngeal (NP) or oropharyngeal (OP) swab

Specimens from suspect AFM cases should be submitted to the ISDH Laboratories (ISDHL). Information about specimen collection, storage, and shipment may be found in CDC’s specimen collection instructions and the ISDHL’s specimen collection and transport instructions. Please contact Lauren Milroy, ISDH vaccine-preventable disease epidemiologist, at 317-234-2807 to report suspect AFM cases prior to submitting specimens. Please direct laboratory questions related to specimen collection or submission to Brian Pope, ISDH virology lab supervisor, at 317-921-5843.

Additional clinician guidance regarding AFM, including information about specimen collection and submission, is available at the links below:

For additional information, please also see the frequently asked questions (FAQs) about AFM, which includes information about reporting, case classification, and laboratory testing.

To learn more about AFM or to report suspected cases of AFM, please contact Lauren Milroy, vaccine-preventable disease epidemiologist, at 317-234-2807 or Additional questions about AFM may be directed to the CDC AFM team at