What is acute flaccid myelitis? Six Minnesota children diagnosed with rare and life-threatening disease

The Minnesota Department of Health (MDH) is investigating an outbreak of a rare but potentially fatal disease called acute flaccid myelitis (AFM) after six children in that state had been diagnosed.

The AFM affects the nervous system, especially the central region of the spinal cord that is filled with gray matter, a type of nerve cell. It is sometimes caused by a viral infection, although environmental factors and genetic disorders can also contribute to its development.

Symptoms often include the sudden onset of muscle weakness in the arms or legs and a loss of muscle tone and reflexes, sometimes as a result of a respiratory illness. Patients may also experience weakness or stiffness in the neck, drooping eyelids, facial looseness, slurred speech, or difficulty swallowing. In severe cases, AFM can lead to paralysis and even death.

The AFM mainly affects children, for reasons that remain unclear. Recent cases in Minnesota – reported in twin cities, central Minnesota and northeastern Minnesota – involve children under the age of 10, all of whom have been hospitalized. The first of six diagnoses was done in mid-September.

"MDH disease investigators are working aggressively with health care providers to gather information on cases," the agency said in a statement. "The department is also in touch with the Centers for Disease Control and Prevention (CDC) to share information."

According to the CDC, there has been a noticeable increase in the number of MFA cases reported nationwide in 2014, which investigators associated with an epidemic of respiratory disease in children caused by a virus called enterovirus D 68 (EVD68).

Stock image of a sick child. iStock

Nevertheless, the CDC estimates that less than one in a million people in the United States will have AFM each year. In Minnesota, three cases of the disease were reported in 2014, but since then, their number has decreased until the last outbreak.

Because AFM can develop as a result of a viral infection, the MDH and the CDC recommend that parents and children take basic steps to avoid infections and stay healthy. This includes frequent handwashing to limit exposure to germs, covering the mouth when coughing or sneezing, and staying home when sick.

If you observe potential symptoms of MFA in your child, for example, if he does not use his arms properly, the MDH recommends that you contact a health care provider as soon as possible. There is no specific treatment for the AFM, so doctors can decide on some treatments on a case-by-case basis.