"What we saw ... is that the majority of children had a fever and a respiratory illness," said Messacar. "Five days later, they would develop pain in the arms and legs, and weakness followed."
Messacar and his colleagues have followed their hospital's 12 AFM patients since 2014. He said most of them are doing better than when they first came into the emergency room, but the majority continue to have some level of disability.
"It's important to understand that there's a wide spectrum of severity of this disease," said Messacar. On one end, you see mild weakness in one extremity, he said. On the other, you've got children who have lost the ability to breathe on their own, and exhibit complete paralysis in their arms and legs.
Patel and Messacar agree: There are no known proven, effective therapies. Both doctors stress the importance of recognizing the early signs of AFM and seeking care as soon as possible.
"A doctor can tell the difference between AFM and other diseases with a careful examination of the nervous system, looking at the location of the weakness, muscle tone and reflexes," according to the CDC's website. "Magnetic resonance imaging (MRI) can be very helpful in diagnosing cases of AFM."
"Finally, by testing the cerebrospinal fluid (CSF, the fluid bathing the brain and spinal cord), clinicians can look for findings suggestive of AFM," according to the CDC.
There is no cure for AFM. Treatment only focuses on alleviating symptoms.
How worried should you be?
"CDC is always concerned when there is a serious illness that is affecting the public, especially when it's affecting children," said Patel. "We're looking closely at what might be causing this, and what might put someone at risk for AFM."
In the meantime, Patel encourages practicing what she calls "general prevention strategies" -- washing your hands with soap and water, getting vaccinated and preventing mosquito bites.
Why is this important? AFM has also been liked to West Nile virus
and other viruses in that family, according to the CDC; in particular, Japanese encephalitis
and Saint Louis encephalitis
. No link has been established between AFM and the Zika virus
There is some good news here. "Enteroviruses tend to appear in the late summer and early fall, and go away in the winter," said Messacar. "So we expect to see [AFM cases] decrease based on the epidemiology of enteroviruses."
"We understand this condition better than we did in 2014, but there's still a lot to learn," said Messacar. "The process is slow, but progress is being made."