It starts out with symptoms similar to a common cold, but it could cause paralysis.
There have reports of 127 cases of a rare polio-like condition affecting children, the Centers for Disease Control said.
So far, 62 cases in 22 states have been confirmed of acute flaccid myelitis or AFM, the CDC said.
The average age of those diagnosed is 4 years old.
It's unclear what's causing the outbreak, which can develop after a viral infection, environmental toxins, and genetic disorders.
AFM affects a person’s nervous system, specifically the spinal cord, causing weakness in one or more limbs.
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