Characterisation of Enterovirus Strains Associated with Acute Flaccid Myelitis in Children in South East Nigeria

Acute flaccid myelitis (AFM) is a serious neurological condition causing limb weakness in children, primarily associated with non-polio enteroviruses including Enterovirus D68 and Enterovirus A71. In Nigeria, where AFP surveillance historically focussed on poliovirus, non-polio enterovirus-associated AFM is likely significantly underdiagnosed. This study characterises enterovirus strains in children presenting with acute flaccid myelitis at neurological centres in Enugu and Anambra states, South East Nigeria. A prospective case-series laboratory study will recruit 80 paediatric AFM cases defined by WHO-adapted clinical criteria over 24 months. Cerebrospinal fluid, stool, and nasopharyngeal specimens will be collected. Stool samples will undergo enterovirus isolation in RD and HEp-2 cell lines, with VP1 gene sequencing for enterovirus typing. EV-D68 will be specifically detected from respiratory specimens by subtype-specific RT-PCR. Cerebrospinal fluid will be subjected to metagenomic sequencing to detect co-infecting neurotropic viruses. MRI findings and clinical outcome data will be correlated with enterovirus type. AFM characterisation in Nigerian children is nearly absent from published literature, with most knowledge derived from US and European cohorts. Findings will establish the enterovirus aetiology of AFM in South East Nigeria and provide fundamental data to guide clinicians and the NCDC in developing AFM surveillance case definitions and response protocols for the country. Keywords: acute flaccid myelitis, enterovirus, EV-D68, South East Nigeria, children