Hepatitis B virus infection, associated factors, knowledge and vaccination status among household contacts of hepatitis B index cases in Mwanza, Tanzania

Objectives: To determine the prevalence of hepatitis B virus (HBV) infection, knowledge regarding HBV, vaccination status, and associated factors among household contacts of HBV index cases in Mwanza, Tanzania. Methods: Between July and August 2023, a cross-sectional study involving 97 index cases and 402 household contacts was conducted. Data were collected using pre-tested structured questionnaire and blood samples were collected from household contacts for HBV surface antigen (HBsAg) testing. Results: The prevalence of HBV among household contacts was 5.4% (95% confidence interval, 2.9-9.0) with a significantly high proportion observed in > 45 years (16.6%) and in males (9.9%). A total of 40.0% of the household contacts had completed the full HBV vaccination series. On multivariate analysis, being male was significantly associated with HBsAg positivity (odds ratio: 7.16, 95% confidence interval: 1.81-28.2, P = 0.005). Conclusion: About one-tenth of adults' male household contacts were HBsAg positive. In addition, the majority of household contacts had poor to fair knowledge regarding HBV infection with more than half being unvaccinated against HBV. There is a need to enhance awareness and education regarding HBV infection among household contacts in Tanzania and other low- and middle-income countries.