U.S. cases of a polio-like illness rise, but there are few clues to its cause

The CDC has confirmed 90 cases of acute flaccid myelitis out of 252 suspected cases

Chase Kulakowski

STILL RECOVERING  Chase Kulakowski, now aged 3, developed acute flaccid myelitis in October 2016. What started as a runny nose quickly progressed to a having lifeless right arm, the Chicago Tribune reported. But surgery and physical therapy has given Chase use of his arm again.

Armando L. Sanchez/Chicago Tribune/TNS via Getty Images

The cause of a rare polio-like disease continues to elude public health officials even as the number of U.S.