- Seasonal trajectory of acute flaccid myelitis (AFM) over the past 5 years suggests that the problem is worsening in the U.S.
- Preliminary data suggest that the 2018 epidemic was associated with both enterovirus D68 (EV-D68) and EV-A71, a well-known cause of hand-foot-and-mouth disease historically uncommon in the U.S.
- EV-D68/AFM epidemics have recurred in 2-year cycles of increasing magnitude, most commonly during seasonal EV-D68 circulation.
Why this matters
- Effective interventions to prevent, limit, or reverse neurologic damage at the time of presentation are lacking.
- Mounting evidence suggests that early intensive physical therapy may benefit nonpolio AFM patients.
- Therapeutic goals should target declines in/loss of flexibility, muscle power, vital capacity, skill, functional stamina, and potential residual deformities.
- AFM refers to a subset of acute flaccid paralysis.
- Enteroviruses are a ubiquitous group of picornaviruses containing 3 polioviruses, ≥100 nonpolio enteroviruses (NPEVs) commonly transmitted by the respiratory route, causing various disease syndromes that manifest in late summer/fall.
- While NPEV immunity is almost universal by early childhood, infections continue to occur because of multiple NPEV types.
- Precipitating EV-D68 infections, early transient viremia appears to resolve at AFM onset; inability to isolate direct virus challenges detection before clinical paralysis manifests.