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 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 were in children around 5 years old. (See "How a Summer Cold Led to a Rare AFM Diagnosis," below.)
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. New spikes in AFM cases have been caused by non-polio enteroviruses such as
enterovirus D68 (EV-D68). These viruses typically cause respiratory symptoms, including asthma-like illnesses. They are common in late summer and early fall, coinciding with these 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. A recent uptick in children with respiratory illnesses due to rhinoviruses and enteroviruses, including EV-D68, was reported by the Centers for Disease Control and Prevention (CDC).
Can AFM be prevented?
We do not know why some children develop this condition after a common viral respiratory infection and others don't. However, parents can remind children to follow these simple steps to help avoid illness:
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 breathe, 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.
Polio vaccines remain important—they prevent paralysis.
Prior to the
polio vaccine, which was introduced in 1955, poliovirus was very common in the United States. It paralyzed and killed thousands every year. Thanks to the vaccine,
poliovirus poliomyelitis has become rare in the United States. Recently, a case of poliomyelitis was reported in New York and
poliovirus was detected in sewage there. It only takes one person infected with poliovirus to spread the disease if we are not protected by vaccination. That's why routine polio vaccines are still important.