RESEARCH ARTICLE A systematic review of Hepatitis B virus (HBV) prevalence and genotypes in Kenya: Data to inform clinical care and health policy Louise O. Downs ID 1,2 , Cori Campbell 1 , Paul Yonga ID 3 , George Githinji 4,5 , M. Azim Ansari ID 1 , Philippa C. MatthewsID 1,6,7,8☯ *, Anthony O. Etyang 4☯ 1 Nuffield Department of Medicine, Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom, 2 Department of Infectious Diseases and Microbiology, John Radcliffe Hospital, Headley Way, Oxford, United Kingdom, 3 CA Medlynks Clinic and Laboratory, Nairobi, and Fountain Projects and Research Office, Fountain Health Care Hospital, Eldoret, Kenya, 4 KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya, 5 Department of Biochemistry and Biotechnology, Pwani University, Kilifi, Kenya, 6 The Francis Crick Institute, London, United Kingdom, 7 Division of Infection and Immunity, University College London, London, London, United Kingdom, 8 Department of Infectious Diseases, University College London Hospital, London, London, United Kingdom ☯ These authors contributed equally to this work. * philippa.matthews@crick.ac.uk Abstract The aim of this systematic review and meta-analysis is to evaluate available prevalence and viral sequencing data representing chronic hepatitis B (CHB) infection in Kenya. More than 20% of the global disease burden from CHB is in Africa, however there is minimal high qual- ity 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 8 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 stud- ies to represent low, moderate, high and very high-risk for HBV infection, identifying 8, 7, 5 and 3 studies in these groups, respectively. We calculated pooled HBV prevalence within each group and evaluated available sequencing data. Pooled HBV prevalence was 3.4% (95% CI 2.7–4.2%), 6.1% (95% CI 5.1–7.4%), 6.2% (95% CI 4.64–8.2) and 29.2% (95% CI 12.2–55.1), respectively. Study quality was overall low; only three studies detailed sample size calculation and 17/23 studies were cross sectional. Eight studies included genetic infor- mation on HBV, with two undertaking whole genome sequencing. Genotype A accounted for 92% of infections. Other genotypes included genotype D (6%), D/E recombinants (1%) or mixed populations (1%). Drug resistance mutations were reported by two studies. There is an urgent need for more high quality seroprevalence and genetic data to represent HBV in Kenya to underpin improved HBV screening, treatment and prevention in order to support progress towards elimination targets. PLOS GLOBAL PUBLIC HEALTH PLOS Global Public Health | https://doi.org/10.1371/journal.pgph.0001165 January 31, 2023 1 / 20 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Downs LO, Campbell C, Yonga P, Githinji G, Ansari MA, Matthews PC, et al. (2023) A systematic review of Hepatitis B virus (HBV) prevalence and genotypes in Kenya: Data to inform clinical care and health policy. PLOS Glob Public Health 3(1): e0001165. https://doi.org/10.1371/ journal.pgph.0001165 Editor: Abraham D. Flaxman, University of Washington, UNITED STATES Received: May 31, 2022 Accepted: November 28, 2022 Published: January 31, 2023 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pgph.0001165 Copyright: © 2023 Downs et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All the data pertinent to the submission are included in the paper and its citations.