Hepatitis E Infection in Nigeria: A Systematic Review

BACKGROUND: Research done globally on hepatitis E virus (HEV) infection is far fewer compared with other types of hepatitis virus infection. Little is known on the prevalence of HEV in Nigeria. AIM: The present study presents the prevalence of HEV infection in Nigeria from a few available research papers on HEV. The detailed statistical analysis was used to analyse the prevalence of HEV in humans and animals. MATERIAL AND METHODS: A literature search in Web of Science, Scopus and PubMed databases was done, and a final 7 articles were selected. Minitab 17.0 was used to perform the correlational and binary logistic analyses. RESULTS: Serum and faecal analysis of blood and stool samples of 1178 humans and 210 pigs (animals) were done, and the presence of anti-HEV IgG or HEV RNA in the study samples were 127 and 138 respectively. Further analysis showed the prevalence of HEV are 10.8% and 65.7% in humans and animals, respectively. Weak positive non-significant association (r = 0.327, p-value = 0.474) was obtained between the target (humans and animal) and the HEV infection (positive) groups. The application of binary logistic regression yielded an equation that can be used to predict the target group from the HEV positive humans or animals. Generally, the logistic model was not statistically significant (p-value = 0.376), and the model was able to explain 9.3% of the deviation or variability of the model. The odds ratio is OR = 1.0344 with 0.9550, 1.204 95% Confidence Interval (CI). Thus, in Nigeria, the odds of prevalence of HEV in animals are 1.0344 higher than humans. CONCLUSION: The risk factors obtained from the few available articles are consistent with the global epidemiology of HEV infection. Food and animal handlers and those that consume unsafe water are the key people at risk of HEV infection in Nigeria.