Serological Evidence of West Nile Virus Exposure in Horses in Sokoto State

West Nile virus (WNV), a mosquito-borne flavivirus, uses birds as reservoir hosts and infects horses and humans as incidental dead-end hosts, causing neurological disease in both species. Equine WNV serosurveys provide a sentinel signal for environmental WNV activity and human exposure risk. This study investigates serological evidence of WNV exposure among horses in Sokoto State, North West Nigeria, where equine husbandry is culturally significant. Serum samples will be collected from 150 horses at the Sokoto State Veterinary Services compound and three privately owned stables in Sokoto, Shagari, and Wurno local government areas. WNV-specific neutralising antibodies will be detected by plaque reduction neutralisation test (PRNT80), with flavivirus cross-reactivity excluded through pre-absorption with dengue virus antigen. Horse owners will be interviewed regarding horse health history, mosquito exposure, prior neurological episodes, and movement across state borders. WNV serological surveys from West African countries indicate equine seroprevalence rates of 10 to 40 percent, suggesting widespread but unrecognised transmission cycles. Findings will characterise WNV activity in Sokoto State's equine population, informing the Federal Ministry of Agriculture's livestock health surveillance and supporting cross-border wildlife health coordination with the Niger Republic under One Health frameworks. Keywords: West Nile virus, horses, seroprevalence, Sokoto State, PRNT