What causes a rare disease that paralyzes kids?

The condition strikes young children. It can start with run-of-the-mill virus symptoms, like fever or sniffles. But, then the kids lose control of their limbs, may have trouble swallowing or breathing, or even end up paralyzed. This terrifying experience happened to more than 570 families since 2014, whose children were struck with an illness called acute flaccid myelitis, or AFM.