First Serological Evidence of West Nile Virus among Individuals with Febrile Illness in a Tertiary Hospital in Port Harcourt, Nigeria

Aims: West Nile Virus (WNV) infection can cause severe illness. Very little is known about the seroepidemiology of WNV infection in individuals with febrile illness in Nigeria and many other developing countries. This study was carried out to determine the seroprevalence of WNV in individuals with febrile illness attending a tertiary hospital in Port Harcourt, Nigeria and to determine if there was an association between WNV infection with age and sex. Study Design: Cross-Sectional Study Place and Duration of Study: Port Harcourt in Rivers State, Nigeria from September 2019 to December 2019. Methods: Human sera were obtained and WNV IgG was determined using the Enzyme-Linked Immunosorbent Assay (ELISA) technique. Results: Of the 90 study subjects tested, WNV IgG antibodies were present in 27 (30.0%) study participants while 63 (70.0%) study participants were seronegative for WNV IgG antibody. With age, a higher prevalence of WNV occurred among 61-70-year-olds (31.3%, n= 5) compared to 41-60 (30.8%, n= 12) and 20-40 (28.6%, n= 10). A higher prevalence of WNV IgG antibodies occurred in males (34.3%, n=12) than their female counterparts (30.9%, n=17). This study indicated that there is no association between WNV infection with age and sex. Conclusion and Recommendations: These results show that WNV is circulating in Rivers State and has accounted for malaria-like infection in the region. It is recommended that WNV serological testing for malaria-infected individuals should be included as a routine test since they are most likely to present similar symptoms of WNV fever. Also, proper hygiene which includes eliminating mosquito breeding sites is recommended to mitigate the spread of West Nile Virus infection.