Over 600 people, mostly young children, have been afflicted with AFM. 2014 was when the disease really began to worry the CDC and doctors around the country. Gracie was the 101st patient. AFM is thought to be caused by a form of the enterovirus, but doctors are still not convinced that they know enough about it. Acute Flaccid Myelitis peaks every other year. 2020 is expected to be the worst year yet.