What is Acute Flaccid Myelitis?
Acute flaccid myelitis (AFM) is a rare but serious condition that affects the nervous system, specifically the spinal cord, causing the muscles and reflexes in the body to work abnormally. This type of condition is not new. Anyone can get AFM or neurologic conditions like it. There are different possible causes, such as viruses, toxins, and genetic disorders.
What are the signs and symptoms?
Most patients will have sudden onset of limb weakness and loss of muscle tone and reflexes. Some patients also will experience:
- facial droop/weakness,
- difficulty moving the eyes,
- drooping eyelids, or
- difficulty with swallowing or slurred speech.
Numbness or tingling is rare in patients with AFM, though some patients have pain in their arms or legs. Some patients with AFM may be unable to pass urine. The most severe symptom of AFM is respiratory failure that can happen when the muscles involved with breathing become weak. This can require urgent ventilator support (breathing machines).
If you or your child develops any of these symptoms, you should seek medical care right away.
What causes AFM?
Acute flaccid myelitis can be caused by a variety of pathogens, including several viruses:
- enteroviruses (polio and non-polio),
- West Nile virus (WNV) and viruses in the same family as WNV, specifically Japanese encephalitis virus and Saint Louis encephalitis virus, and
AFM is one of a number of conditions that can result in neurologic illness with limb weakness. Such illnesses can result from a variety of causes, including viral infections, environmental toxins, genetic disorders, and Guillain-Barre syndrome, a neurologic disorder caused by an abnormal immune response that attacks the body’s nerves. Oftentimes, however, despite extensive laboratory testing, a cause for AFM is unable to be identified.
How is AFM treated?
There is no specific treatment for AFM, but a neurologist may recommend certain interventions on a case-by-case basis.
In 2016, two confirmed cases of AFM were reported in Illinois. The Illinois Department of Public Health (IDPH) is re-emphasizing the importance of continued vigilance in identifying cases of AFM among all age groups, irrespective of enterovirus status. Reporting of these cases will help public health officials monitor for increases in this illness and better understand potential causes, risk factors, and preventive measures or therapies. We are asking all clinicians to report AFM cases to the local health department, governing the jurisdiction where the patient lives.
Clinicians suspecting AFM in patients meeting the probable or confirmed case definition (irrespective of laboratory testing results) are asked to report these cases to the local health department governing the jurisdiction where the patient lives, or to the Illinois Department of Public Health Communicable Disease Control Section at 217-782-2016. Clinicians should complete the patient summary form and submit it to their LHD as early as possible. Clinicians or infection control practitioners that have access to enter reportable diseases into the Illinois National Electronic Disease Surveillance System (I-NEDSS) should also enter the case’s information into the system’s AFM module. Local health departments (LHD) should report AFM cases into I-NEDSS as an AFM case if the clinician has not done so.
Specimen Collection and Testing
Clinicians should 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 a diagnosis of AFM. CDC has specimen collection procedures on their website. Please refer to CDC’s collection procedures for the most up-to-date instructions. NOTE: specimen coordination should be done in conjunction with the LHD and/or IDPH CD section prior to shipment.
The following three forms must be completed and included with all specimen submissions to IDPH laboratory:
- IDPH Communicable Diseases Laboratory Test Requisition Form
- CDC 50.34 DASH Form: (Please contact the IDPH laboratory if assistance is needed with this form.)
- CDC AFM Patient Summary Form
Medical providers and infection control practitioners should contact their local health department with questions about AFM reporting. Local health departments with questions should contact IDPH Communicable Disease Control Section at 217-782-2016.