Seropositivity of West Nile virus among acute febrile patients in Ilorin, Nigeria

Introduction. West Nile Virus (WNV), a member of Flaviviridae family, is one of the most widely distributed arboviruses in the world. In developing countries like Nigeria, fever resulting from the WNV infection is often presumptively ascribed to malaria or typhoid due to misdiagnosis and low-level awareness of the viral infection. This study determined the prevalence of WNV IgM and IgG antibodies among febrile patients in the Ilorin metropolis. Materials and methods. A total of two hundred (200) blood samples were collected from consenting patients and each serum was screened for anti-WNV IgM and IgG antibodies using indirect enzyme-linked immunosorbent assay (ELISA). Statistical correlation and logistic regression analysis were conducted. Results. Overall, 6% (12/200) anti-WNV IgM seropositivity rate was recorded amongst the acute febrile patients with higher prevalence (6.30%) in females than in males (5.45%). Anti-WNV IgG positivity rate of 52% (104/200) was recorded, with 50.67% positivity rate in males and 38.95% in female participants. The convalescence phase posited by the 5.4% (11/200) co-detection of anti-WNV IgG and IgM antibodies among the participants was recorded. A statistical correlation was noticed with the age and religion of respondents to WNV serological positivity while gender, occupation, use of mosquito nets and formal education had no positive correlation at p 0.05. However, based on odd ratio at 95% CI and logistic regression coefficients, the evaluated risk factors such as blood transfusion, residency, malaria parasite, and proximity to stagnant water and bush were significant to anti-WNV IgG and IgM positivity. Conclusion. The findings of this study show the circulation of WNV in the study area. There is an urgent need for clinicians/physicians to include screening for the West Nile virus in cases of febrile patients before the commencement of treatment.