Epidemiol Health.  2020;42(1):e2020071. 10.4178/epih.e2020071.

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

• Abdullahi IN
• Emeribe AU
• Ghamba PE
• Omosigho PO
• Bello ZM
• Oderinde BS
• Fasogbon SA
• Olayemi L
• Daneji IM
• Musa MH
• Nwofe JO
• Onukegbe NB
• Okume CC
• Musa S
• Gwarzo AM
• Ajagbe OOR

• KMID: 2512777
• DOI: http://doi.org/10.4178/epih.e2020071

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.

Keyword

One Health, Zoonosis, West Nile virus, Nigeria, Pooled prevalence