A systematic review of Hepatitis B virus (HBV) prevalence and genotypes in Kenya: Data to inform clinical care and health policy

Abstract

AbstractMore than 20% of the global disease burden from chronic hepatitis B infection (CHB) is in Africa, however there is minimal high quality seroprevalence data from individual countries and little viral sequencing data available to represent the continent. We undertook a systematic review of the prevalence and genetic data available for hepatitis B virus (HBV) in Kenya using the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) 2020 checklist. We identified 23 studies reporting HBV prevalence and 25 studies that included HBV genetic data published in English between January 2000 and December 2021. We assessed study quality using the Joanna Briggs Institute critical appraisal checklist. Due to study heterogeneity, we divided the studies to represent low, moderate, high and very high-risk for HBV infection. We calculated pooled HBV prevalence within each group and evaluated available sequencing data. We also assessed whether reported HBV biomarkers could be applied to determine treatment eligibility. Eight studies were identified in the low-risk group, seven in the moderate risk group, five in the high-risk group and three in the very high-risk group for HBV infection. Pooled HBV prevalence was 3.31% (95% CI 2.62-4.01%), 5.58% (95% CI 3.46-7.7%), 6.17% (95% CI 4.4-9.94) and 31.39% (95% CI 9.5-53.09) respectively. Study quality was overall low, representing a small geographical location or a limited population subset. Only three studies detailed sample size calculation and 17/23 studies were cross sectional. Eight studies included genetic information on HBV, representing 247 individuals. Six studies sequenced one or two genes; two undertook whole genome sequencing, representing 22 participants. 92% people were infected with genotype A. Other genotypes included genotype D (6%), D/E recombinants (1%) or mixed populations (1%). Drug resistance mutations were reported by two studies. Seven studies presented additional biomarkers alongside HBsAg, however none provided sufficient information to deduce treatment eligibility.