Epidemiology and Health  2020;42(1):e2020071-

doi:10.4178/epih.e2020071

Distribution pattern and prevalence of West Nile virus infection in Nigeria from 1950 to 2020: a systematic review

Idris Nasir ABDULLAHI 1 ; Anthony Uchenna EMERIBE ; Peter Elisha GHAMBA ; Pius Omoruyi OMOSIGHO ; Zakariyya Muhammad BELLO ; Bamidele Soji ODERINDE ; Samuel Ayobami FASOGBON ; Lawal OLAYEMI ; Isa Muhammad DANEJI ; Muhammad Hamis MUSA ; Justin Onyebuchi NWOFE ; Nkechi Blessing ONUKEGBE ; Chukwudi Crescent OKUME ; Sanusi MUSA ; Abubakar Muhammad GWARZO ; Odunayo Oyetola Rahmat AJAGBE

Affiliations

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Country

Republic of Korea

Language

English

Abstract

OBJECTIVES:West Nile virus (WNV) is a re-emerging mosquito-borne viral infection. This study investigated the pooled prevalence pattern and risk factors of WNV infection among humans and animals in Nigeria.

METHODS:A systematic review was conducted of eligible studies published in PubMed, Scopus, Google Scholar, and Web of Science from January 1, 1950 to August 30, 2020. Peer-reviewed cross-sectional studies describing WNV infections in humans and animals were systematically reviewed. Heterogeneity was assessed using the Cochrane Q statistic.

RESULTS:Eighteen out of 432 available search output were eligible and included for this study. Of which 13 and 5 were WNV studies on humans and animals, respectively. Although 61.5% of the human studies had a low risk of bias, they all had high heterogeneity. The South West geopolitical zone of Nigeria had the highest pooled prevalence of anti-WNV immunoglobulin M (IgM; 7.8% in humans). The pooled seroprevalence of anti-WNV IgM and immunoglobulin G (IgG) was 7.1% (95% confidence interval [CI], 5.9 to 8.3) and 76.5% (95% CI, 74.0 to 78.8), respectively. The WNV RNA prevalence was 1.9% (95% CI, 1.4 to 2.9), while 14.3% (95% CI, 12.9 to 15.8) had WNV-neutralizing antibodies. In animals, the pooled seroprevalence of anti-WNV IgM and IgG was 90.3% (95% CI, 84.3 to 94.6) and 3.5% (95% CI, 1.9 to 5.8), respectively, while 20.0% (95% CI, 12.9 to 21.4) had WNV-neutralizing antibodies. Age (odds ratio [OR], 3.73; 95% CI, 1.87 to 7.45; p<0.001) and level of education (no formal education: OR, 4.31; 95% CI, 1.08 to 17.2; p<0.05; primary: OR, 7.29; 95% CI, 1.80 to 29.6; p<0.01) were significant risk factors for WNV IgM seropositivity in humans.

CONCLUSIONS:The findings of this study highlight the endemicity of WNV in animals and humans in Nigeria and underscore the need for the One Health prevention and control approach.