• Article
  • November 20, 2018

Hospitals See Uptick in Acute Flaccid Myelitis, a Rare, Polio-Like Illness

The Centers for Disease Control continues to monitor and track new cases.


The Centers for Disease Control and Prevention (CDC) is now monitoring 252 suspected cases of acute flaccid myelitis (AFM), a rare and polio-like illness that affects mostly children. There are now 106 confirmed cases in 29 states so far in 2018—a number that is significantly higher than the 33 cases confirmed in 2017.

Children's hospitals across the country are seeing potential AFM cases. At Children's Health in Dallas, six patients presented with AFM since this summer. Benjamin Greenberg, M.D., neurologist at Children's Health and associate professor at UT Southwestern Medical Center, says the hospital is working to confirm the diagnosis in an additional patient and may see more before the outbreak is over.

"We've treated many children with this condition over the last 10 years," he says. "There are quite variable recoveries, but with acute therapy and then long term rehabilitation, we see most of our patients making gains. Progress occurs slowly and through very intensive work that can span years."

Greenberg says children's hospitals are on the front line for diagnosing and treating these patients, and having uniform policies for testing children and reporting all cases to public health officials is critical. "For the community, we are reassuring everyone this remains a rare event, but for the public health community, we are warning them more resources need to be devoted to confirm the cause and develop an action plan for preventing future outbreaks."

According to the CDC, here's what we know about AFM:

  • The condition is rare. Ninety percent of cases affect children under the age of 18, with an average patient age of 4 years old.
  • Symptoms include sudden weakness and loss of muscle tone in arms and legs, as well as difficulty swallowing, facial drooping and slurred speech.
  • The last major uptick in AFM cases occurred in 2014 and coincided with an outbreak of enterovirus D68 (EV-D68).
  • A respiratory illness, it spreads from person to person by coughing or sneezing and typically begins with cold-like symptoms, and can lead to sudden paralysis and infections in the heart and brain. One child died of AFM in 2017.
  • Parents can protect their kids from serious illnesses like AFM by encouraging proper handwashing techniques, ensuring their child's vaccines are up to date, and using insect repellent to prevent mosquito bites.

From August 2014 through September 2018, the CDC has received information on 386 confirmed cases. "I am frustrated that despite our efforts we haven't been able to identify the cause of this mystery illness—we continue to investigate to better understand the clinical picture of AFM cases, risk factors and possible causes of the increase in cases," says Nancy Messonnier, M.D., from the CDC's National Center for Immunization and Respiratory Diseases.

Messonnier says researchers don't know who may be at higher risk for developing AFM or the reasons why they may be at higher risk. "We don't fully understand the long-term consequences of AFM," she says. "We know some patients diagnosed with AFM have recovered quickly and some continue to have paralysis and require ongoing care."

Greenberg recommends any child with new onset weakness or paralysis should be imaged with a MRI of the spine, and they should have nasopharyngeal swabs and cerebrospinal fluid tested for enteroviruses.

The CDC is urging health care providers to be vigilant for AFM among their patients and to send information about suspected cases to their local health departments.

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