Acute flaccid myelitis (AFM) is a rare but serious illness that can cause sudden weakness of muscles, loss of reflexes, and paralysis. Three spikes in cases of AFM have occurred in the United States—in late summer to early fall of 2014, 2016, and 2018—with over 660 confirmed cases. Most of the AFM cases in these outbreaks have been in children around 5 years old.
While the condition sounds frightening, keep in mind that AFM is very rare. The chances of a child getting it are less than one in a million.
What causes AFM?
Several viruses (for example, West Nile virus) are known to cause AFM, but experts agree that these new spikes in AFM cases have been caused by non-polio enteroviruses such as
enterovirus D68 (EV-D68). These viruses typically cause just a mild cold. They are common in late summer and early fall, coinciding with these latest AFM spikes. In 2014, there was a rise in AFM cases during an
EV-D68 outbreak. Since that 2014 outbreak, enteroviruses have been the most commonly identified viruses in lab samples from patients who had AFM.
How to protect your children?
Since we don't know why some children develop this condition after a common viral respiratory infection and others don't, right now there are no specific actions to prevent AFM. The best thing you can do to protect your children from getting sick from any virus is to keep up with the basics:
Immediately seek medical care if your child develops sudden arm or leg weakness, a droopy face, or has difficulty swallowing or speaking.
Is there a treatment for AFM?
There is no specific treatment for AFM. However, doctors who specialize in neurologic and infectious diseases will tailor a treatment plan and recommend certain interventions, depending on the case. During the acute phase of the illness, most of the treatment is supportive—helping the child to breath, for example. Many children with AFM have also benefited from early physical and occupational therapy.
AFM Physician Consult and Support Portal was created to connect medical professionals with neurologists specializing in AFM and other rare, complex neuro-immune disorders.
Recent U.S. AFM cases were not caused by poliovirus
While AFM is often called a "polio-like illness," we know that the cases seen in the United States have not been caused by the poliovirus. The last time the poliovirus was found in the United States was in 1993.
Prior to the
polio vaccine, which was introduced in 1955, poliovirus leading to paralytic poliomyelitis was very common in the United States. It paralyzed and killed thousands of people every year. Thanks to the vaccine, poliovirus poliiomyelitis has been eliminated in the United States. But it still occurs in other parts of the world, and it would only take one person infected with poliovirus coming from another country to bring the disease back here if we were not protected by vaccination. That's why routine polio vaccines are still important.