Seroprevalence of Occult Hepatitis B Virus Infection Using Anti-HBc and Nucleic Acid Amplification (HBV DNA) Technique in a Resource-Limited Setting: a Systematic Review and Meta-Analysis of Nigerian Literature

Nigeria bears a significant global burden of chronic hepatitis B virus (HBV) infection and epidemiological findings reveal important associations between occult hepatitis B virus infection (OBI) and the persistence of HBV infections in endemic regions. Therefore, this study conducted a systematic review and meta-analysis of the available data from the literature to estimate the prevalence of OBI in Nigeria, assess the implications of this burden on blood safety, and examine potential strategies to enhance the detection of OBI toward the improvement of HBV testing for blood safety in Nigeria. The study was conducted using the PRISMA guidelines, targeting available literature from MEDLINE/PubMed, Advanced Google Scholar, AJOL, and gray literature through Google search. Full-text articles and gray literature published up to January 2022 that provide prevalence estimates of OBI in Nigeria were examined for the fulfillment of eligibility criteria. Quality assessment of selected articles was performed using the recommended critical appraisal tool by Joanna Briggs Institute. A random effect meta-analysis was conducted on all eligible data while heterogeneity was assessed through subgroup analyses. Relevant data was then extracted to compare OBI in populations’ positive/negative for anti-HBc. A total of 1047 records were found across the electronic databases. However, 10 studies met the inclusion criteria, allowing a meta-analysis of 1955 subjects for OBI and 1335 for exposed subjects (anti-HBc). There was a significant difference in the proportion of included studies as validated by the test of independence. The overall prevalence of OBI was 9.85% (95% CI (4.89–18.83), I2 = 94%) with an exposure rate of 61.14% (95% CI (37.40–80.56), I2 = 57%). Both OBI and anti-HBc testing were reported by six studies which were used to test the strength of association. Using proportional analysis, there was positivity for OBI in 173 out of 263 anti-HBc-positive participants (65.78%). To further investigate the relationship between OBI and exposure, the pooled odd ratios comparing the proportion of OBI in exposed individuals as measured by anti-HBc were assessed and showed a significant association, 2.30 (95% CI (0.23–23.47), P < 0.01). Our findings elucidate the need to include screening for OBI in the health policies on HBV infection and reiterate an urgent need for a careful re-evaluation of the national HBV screening algorithm (especially in blood donors). This meta-analysis shows that in HBsAg-negative blood donors, anti-HBc positivity could guide further investigation of the presence of HBV in potential blood donors.