Caitlin Rivers, an epidemiologist at the Johns Hopkins Center for Health Security, has voiced concern over the timing of the rise in cases. “...the time of year is right,” Rivers noted, hinting at the possibility of a surge in AFM cases this year.

D68, a seasonal virus that can -- in rare cases -- cause polio-like symptoms in children. Dr. Kristin Moffitt, an infectious disease specialist at Boston Children's Hospital, explains.

Scientists have found evidence that levels of enterovirus D68, which can cause a rare, polio-like condition in kids, has been spiking nationally since August.