​Acute Flaccid Myelitis

Acute Flaccid Myelitis (AFM) Basics

Acute flaccid myelitis (AFM) is a rare but serious condition. It affects a person’s nervous system, specifically the spinal cord, causing weakness in one or more limbs. AFM is not a new condition, and can be caused by a variety of viruses, environmental toxins, and genetic disorders. However, many cases of AFM do not have a cause identified. AFM itself is not contagious.

Since August 2014, there have been an increased number of people in the United States reported with AFM. The majority of these cases have not had a cause identified, but the Centers for Disease Control and Prevention (CDC) is actively investigating all cases to learn what may be causing the increase.

CDC began tracking cases of AFM in 2014, and their surveillance shows that cases of AFM have peaked in late summer to early fall of even-numbered years. The reason for this cycle is not yet known.  Most cases occur in children, and cases are scattered all over the United States. 

Symptoms of AFM

The main symptom of AFM is sudden weakness in one or more limbs. In addition, some people also have sudden weakness in their eyes, eyelids, or their face, or may have trouble swallowing or speaking clearly. Many cases have had cold- or flu-like symptoms in the days or weeks before their weakness started, but some did not. The symptoms of AFM are similar to the symptoms of other serious diseases, so it is important to seek medical care immediately if they occur.

Testing and Treatment of AFM

There is no test for AFM, but CDC experts use a combination of symptoms, lab tests, and MRI images of the spinal cord and brain to determine if someone has AFM. Most cases of AFM are hospitalized, but deaths are extremely rare. 

There is no specific treatment for AFM, but patients often receive anti-viral medications or antibiotics while in the hospital. Many patients also begin physical therapy. Recovery is unpredictable, and can range from full recovery in a matter of days to long-term limb weakness.


Cases of AFM in Maryland (2014-2018) as of November 17, 2020

​Year ​Investigations ​Cases Confirmed by CDC
​2020 ​2 ​​0
2019​ 6 ​3
​2018 ​8 6
​2017 ​4 ​1
2016​ ​3 ​2
​2015 ​1 ​1
​2014 ​0 ​0
 All confirmed Maryland cases have occurred in children, in multiple counties. Confirmation of cases from CDC takes approximately one month.