Acute Flaccid Myelitis (AFM)

AFM Basics

Disease Description

Acute flaccid myelitis (AFM) is a rare but serious condition affecting the nervous system, specifically the spinal cord. AFM causes weakness in the body’s muscles and reflexes.

  • Symptoms

AFM causes sudden arm and/or leg weakness. AFM also causes loss of muscle tone and reflexes. Someone with AFM might also have:

  • facial droop/weakness
  • difficulty moving the eyes
  • drooping eyelids
  • difficulty with swallowing or slurred speech
  • pain in the arms or legs

Rarely, someone with AFM might have numbness or tingling in limbs, and difficulty passing urine. Some patients might have difficulty breathing due to muscle weakness and need ventilator support. AFM can also cause severe neurologic complications.

If you see potential symptoms of AFM in your child, (for example, if he or she is not using an arm), contact your health care provider right away. AFM can be diagnosed by examining your child’s nervous system, taking an MRI scan, testing the cerebral spinal fluid, and checking nerve conduction. It is important that tests are done as soon as possible after someone develops symptoms. While there is no specific treatment for AFM, doctors may recommend certain interventions on a case-by-case basis.

  • Causes

There is no known single cause of AFM, but the U.S. Centers for Disease Control and Prevention (CDC) believes viruses, including enteroviruses, might be associated with AFM. In the U.S., most patients with AFM occurring since 2014 had symptoms consistent with a viral illness (ex: runny nose, fever, cough), just before their AFM onset.  Sometimes, the cause of a patient’s AFM may not be identified.

  • Prevention

There is no single, specific cause of AFM. However, since AFM can develop as a result of a viral infection, The Georgia Department of Public Health recommends parents and children take basic steps to avoid infections and stay healthy including making sure you and your family are up to date on your vaccinations, protecting yourself from insect bites, and washing your hands often.

Additional Information for Patients and Caregivers

Information for Health Professionals

Reporting

  • Reporting AFM

All individual cases of AFM should be reported to the Georgia Department of Public Health. Find out more about what needs to be reported, who needs to report diseases, which forms to use and where to find out more about the disease.

Clinical Features and Epidemiology

  • AFM in the United States

The Centers for Disease Control and Prevention (CDC) has requested states provide information on suspect AFM cases since the fall of 2014, when clusters of pediatric cases with AFM were identified in Colorado and Kansas. At the same time, there was an ongoing nationwide outbreak of Enterovirus D68 (EV-D68).  States have been reporting suspect AFM cases to CDC and submitting specimens for testing since the fall of 2014. Most cases occurred between August and October, with increases every two years since 2014. At this same time of year, many viruses commonly circulate, including enteroviruses. AFM is rare, and the U.S. Centers for Disease Control and Prevention (CDC) estimates that less than one in a million people in the U.S. will get AFM each year. Most reported cases in the U.S. have been in children, but people of any age can get AFM.

  • From August 2014 to December 2014, CDC verified reports of 120 children in 34 states who developed AFM.
  • In 2015 there were 22 confirmed AFM cases reported from 17 states.
  • In 2016 there were 149 confirmed AFM cases reported from 39 states.
  • In 2017, 35 confirmed AFM cases were reported from 16 states.
  • In 2018, 235 confirmed AFM cases were reported from 41 states
  • As of September 3, 2019, 20 confirmed AFM cases have been reported from 9 states
  • AFM in Georgia

Since August 2014, 15 cases of AFM have been reported to the Georgia Department of Public Health, with ages ranging from 6 months – 17 years at weakness onset. Establishing routine surveillance for AFM in Georgia is necessary to determine the burden of this syndrome and establish baseline incidence. Suspect cases of AFM reportable to DPH are classified according to the following criteria:

Case Definition

  • Clinical Criteria: An illness with onset of acute flaccid limb weakness
     
  • Confirmed case: Clinically compatible case AND MRI showing spinal cord lesion largely restricted to gray matterb,c and spanning one or more spinal segments
     
  • Probable case: Clinically compatible case AND CSF showing pleocytosis (white blood cell count >5 cells / mm3).

Laboratory Testing

Specimens should be collected from patients suspected of having AFM as soon as possible, ideally on the day of limb weakness onset. Requested specimens include:

  • Cerebrospinal Fluid (CSF)
  • Blood serum
  • A nasopharyngeal swab
  • Stool
    • Two stool specimens collected as soon after onset of limb weakness as possible and separated by 24 hours

For detailed instructions visit the CDC’s webpage on AFM specimen collection. DO NOT ship specimens directly to CDC, call your local health department to coordinate shipment to the Georgia Public Health Laboratory, who will then coordinate testing and shipping with CDC.

Provider Resources


Footnotes:

aThe clinical case definition for AFM was changed to include all ages, as opposed to only those occurring in patients ≤21 years old, in August 2015 [3]

bSpinal cord lesions may not be present on initial MRI; a negative or normal MRI performed within the first 72 hours after onset of limb weakness does not rule out AFM.

cTerms in the spinal cord MRI report such as “affecting mostly gray matter,” “affecting the anterior horn or anterior horn cells,” “affecting the central cord,” “anterior myelitis,” or “poliomyelitis” would all be consistent with this terminology.

Case Counts

Report Year Number of AFM Cases*
Reported AFM Cases in Georgia
2014 1
2015 1
2016 5
2017 1
2018 6
2019** 1

*Includes Confirmed or Probable AFM cases

**Preliminary Case Count


References

  1. Revision to the Standardized Case Definition for Acute Flaccid Myelitis [Internet]. Council of State and Territorial Epidemiologists; 2017. Retrieved from: http://c.ymcdn.com/sites/www.cste.org/resource/resmgr/2017ps/2017psfinal... [Accessed August 10, 2018]
  2. About Acute Flaccid Myelitis [Internet]. Centers for Disease Control and Prevention; 2018. Retrieved from: http://www.cdc.gov/acute-flaccid-myelitis/about-afm.html [Accessed August 10, 2018]
  3. Standardized Case Definition for Acute Flaccid Myelitis [Internet]. Council of State and Territorial Epidemiologists; 2015. Retrieved from: http://c.ymcdn.com/sites/www.cste.org/resource/resmgr/2015PS/2015PSFinal... [Accessed August 10, 2018]
  4. AFM Investigation [Internet]. Centers for Disease Control and Prevention; 2018. Retrieved from: https://www.cdc.gov/acute-flaccid-myelitis/afm-surveillance.html [Accessed August 10, 2018]

Additional Resources