Enterovirus D68–Associated Acute Flaccid Myelitis, United States, 2020

Abstract

A FM is a syndrome characterized by the acute onset of flaccid limb weakness and lesions in the gray matter of the spinal cord visible on magnetic resonance imaging; the lesions represent damage to the lower motor neurons in the anterior horns. This feature distinguishes AFM from other disorders associated with acute flaccid limb weakness or paralysis, such as disorders of peripheral nerves (e.g., Guillain-Barré syndrome) or neuromuscular transmission (e.g., myasthenia gravis or botulism). AFM can be caused by multiple infectious and noninfectious etiologies. Poliovirus, nonpolio enteroviruses, and flaviviruses are all known to cause AFM in a subset of persons who are infected (1-4). In addition, noninfectious etiologies such as neuroinflammatory conditions or spinal vascular disease can result in a clinical and radiographic picture that overlaps with that of AFM caused by infection (5-7). Although the

Enterovirus Surveillance (EVSurv) in Germany

“…Data from monitoring the circulation of enteroviruses will be increasingly important in the post-polio eradication era to detect poliovirus and other enteroviruses, causing potentially severe infections. For example, starting from 2014, there were outbreaks of enterovirus D68 associated with a severe respiratory infection and polio-like acute flaccid myelitis (AFM) in North America and several European countries [38][39][40][41][42][43][44][45][46]. There was also an upsurge in reported AFP cases in Germany in 2016 (total n = 78), revealing at least 16 cases presenting with AFM [47].…”

Potential for increased prevalence of neuropathic pain after the COVID-19 pandemic

“…Epidemic peaks of acute flaccid myelitis have been observed particularly in the United States every 2 years since 2012 coincident with peaks in enterovirus transmission, and a causal relationship is highly suspected. 34 In addition to motor deficit, common symptoms at clinical evaluation include limb pain in a third of cases (in a cohort of 238 consecutive patients), which most probably corresponds to neuropathic pain. 34 The long-term outcome is considered as generally favorable, but motor sequelae are possible and chronic pain has been reported after 1 year in 2 children of 8 affected with acute transverse myelitis.…”

“… 34 In addition to motor deficit, common symptoms at clinical evaluation include limb pain in a third of cases (in a cohort of 238 consecutive patients), which most probably corresponds to neuropathic pain. 34 The long-term outcome is considered as generally favorable, but motor sequelae are possible and chronic pain has been reported after 1 year in 2 children of 8 affected with acute transverse myelitis. 44 …”

Enterovirus D: A Small but Versatile Species

“…During a widespread outbreak in the United States of America in 2014, EV-D68 gained public interest due to its high morbidity in children [ 148 ]. Severe complications arose from respiratory illness to a polio-like disease, described as AFM [ 160 ]. The recently characterized strains of EV-D68 from the 2014 outbreak seem to be less susceptible to attenuation at 37 °C, can infect neural tissues independently of SA, and can utilize the neural receptor ICAM-5 (abundantly found in the telencephalon and also identified as a receptor for prototypic strains) [ 123 , 161 , 162 , 163 ].…”