West Nile Virus Sero-Reactive Animals Reveal Potential Zoonotic Threat In Nigeria

Abstract

West Nile Virus (WNV) is a zoonotic mosquito borne arbovirus that causes encephalitis in horses and human. It is a pathogen of public  health importance globally. Data on WNV epizootics in Nigeria is limited, necessitating seroprevalence studies in animals. In this study,  118 sera from Polo horses and 66 archival sera from 31 horses, 10 chicken, 15 rabbits and 10 dogs in Northern and South-Western Nigeria  were screened for WNV using West Nile multi-species competitive ELISA. The overall seroprevalence of WNV was 78.26% (n=144).  In horses, 93.28% (n=139) of the 149 horse sera were positive, all the 10 chicken samples tested were negative to WNV, only 1 (6.67%) of  the 15 rabbits sera tested positive and 4(40%) of 10 dog sera tested was positive. The lack of sero-reactivity in domestic chickens in this  study does not suggest a low incidence rate in wild birds that are known reservoirs. Sero-reactivity in rabbits and dogs indicates their  exposure and susceptibility to WNV and therefore requires further investigation. The high sero-reactivity recorded in horses reiterates  the important role they play in WNV epizootics which underscores the public health risk associated with WNV at the human-animal  interface in Nigeria.