The changing epidemiology of acute flaccid paralysis warrants a paradigm shift in surveillance

The importance of enterovirus surveillance in a post-polio world

Poliovirus is known to most people in the world as the cause of polio, a devastating paralytic disease from the past. Success in polio eradication has understandably translated into stricter containment plans for poliovirus, coordinated by WHO. In this Personal View, we discuss the impact of recent biosafety level 3+ guidelines for handling potential poliovirus-containing diagnostic specimens, which has resulted in closure of many national WHO poliovirus reference laboratories. This reduction in laboratory capacity has a knock-on effect of capability to detect and characterise non-polio enteroviruses in samples obtained from patients with neurological symptoms. The development is of concern given the widespread circulation of non-polio enteroviruses, their role as the most common cause of meningitis worldwide, and their involvement in other severe neurological conditions, such as acute flaccid myelitis and encephalitis. These disease presentations have increased substantially in the past decade, and have been associated with major outbreaks of enterovirus D68 and enterovirus A71, leaving many who survived with lasting paralysis and disabilities. To address this growing gap in diagnostic and surveillance capability, we have established the European Non-Poliovirus Enterovirus Network (also known as ENPEN) as a supra-national, non-commercial, core reference consortium. Our consortium will develop, test, and implement generic surveillance platforms for non-polio enteroviruses and other emerging viral diseases.

Outcome of paediatric acute flaccid myelitis associated with enterovirus D68: a case series

Enterovirus D68 (EV-D68) is an emerging infection associated with acute flaccid myelitis (AFM). Cases of AFM associated with EV-D68 infection have increased in recent years and the evidence for a causal link is growing. However, our understanding of the epidemiology, clinical features, prognosis, and neurological sequelae of EV-D68 requires ongoing surveillance and investigation. We report five cases of AFM in previously typically developing children (2-6y) from South East Scotland during September and October 2016 after infection with EV-D68 (all detected in the nasopharyngeal aspirates). All cases presented with significant neurological symptoms, which were severe in two cases requiring intensive care support because of respiratory paralysis. At 18-month follow-up, two cases remain ventilator-dependent with other cases requiring ongoing community rehabilitation. These cases represent one of the largest reported paediatric cluster of AFM associated with EV-D68 in Europe. The epidemiology and clinical information add to the knowledge base and the 18-month outcome will help clinicians to counsel families. WHAT THIS PAPER ADDS: Nasopharyngeal aspirate is more sensitive for viral isolation and isolated in all cases. Clinical outcome at 18 months after enterovirus D68 with acute flaccid myelitis provides information on extent of recovery and level of disability.