Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study.

Background: The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate viral hepatitis by 2030. Although no virological cure exists for hepatitis B virus (HBV) infection, existing therapies to control viral replication and prophylaxis to minimise mother-to-child transmission make elimination of HBV feasible. We aimed to estimate the national, regional, and global prevalence of HBsAg in the general population and in the population aged 5 years in 2016, as well as coverage of prophylaxis, diagnosis, and treatment. Method(s): In this modelling study, we used a Delphi process that included a literature review in PubMed and Embase, followed by interviews with experts, to quantify the historical epidemiology of HBV infection. We then used a dynamic HBV transmission and progression model to estimate the country-level and regional-level prevalence of HBsAg in 2016 and the effect of prophylaxis and treatment on disease burden. Finding(s): We developed models for 120 countries, 78 of which were populated with data approved by experts. Using these models, we estimated that the global prevalence of HBsAg in 2016 was 3.9% (95% uncertainty interval [UI] 3.4-4.6), corresponding to 291 992 000 (251 513 000-341 114 000) infections. Of these infections, around 29 million (10%) were diagnosed, and only 4.8 million (5%) of 94 million individuals eligible for treatment actually received antiviral therapy. Around 1.8 (1.6-2.2) million infections were in children aged 5 years, with a prevalence of 1.4% (1.2-1.6). We estimated that 87% of infants had received the three-dose HBV vaccination in the first year of life, 46% had received timely birth-dose vaccination, and 13% had received hepatitis B immunoglobulin along with the full vaccination regimen. Less than 1% of mothers with a high viral load had received antiviral therapy to reduce mother-to-child transmission. Interpretation(s): Our estimate of HBV prevalence in 2016 differs from previous studies, potentia