Epidemiology of hepatitis B virus infection in people living in poverty in the central-west region of Brazil

Background: People living in poverty (PLP) are highly vulnerable to hepatitis B virus (HBV) infection. This study aimed to investigate the epidemiology of HBV infection in PLP in the metropolitan region of Goiânia, Goiás State, in the Central-West Region of Brazil. Methods: A cross-sectional study was conducted from August to December 2016 in adults aged ≥12 years living in poverty. The following serological markers for HBV were investigated: Hepatitis B surface antigen (HBsAg), antibody to HBV core antigen (total anti-HBc), IgM anti-HBc, and hepatitis B surface antibody (anti-HBs), which were detected by enzyme-linked immunosorbent assay (ELISA). Poisson regression analysis with robust variance was performed to verify the factors associated with HBV exposure. Results: The study included 378 participants. The overall prevalence rate of HBV (any viral marker) was 9.8% (95% confidence interval [CI], 7.2-13.2). The prevalence rate of HBsAg in combination with total anti-HBc was 0.8% (95% CI, 0.3-2.4), total anti-HBc in combination with anti-HBs was 7.7% (95% CI, 5.4-10.9), and total anti-HBc alone was 1.3% (95% CI, 0.5-3.0) in the population. Furthermore, isolated positivity for anti-HBs was identified in only 25.4% (95% CI, 21.3-30.0) of the participants. Multiple regression analysis revealed that age (adjusted prevalence ratio [APR], 1.04; 95% CI, 1.01-1.07), female sex (APR, 2.18; 95% CI, 1.01-4.73), sexual intercourse under the influence of alcohol (APR, 2.49; 95% CI, 1.36-7.06), and exposure to Treponema pallidum (APR, 3.10; 95% CI, 1.36-7.06) were associated with HBV exposure. Conclusion: There was a high prevalence of HBV exposure in PLP in the Central-West Region of Brazil, indicating significant viral spread of the infection. Additionally, there was low serological evidence of immunisation against hepatitis B, indicating that a large proportion of the participants in this study are susceptible to the infection. The results support the need for public health policies that facilitate access to the existing healthcare services in hard-to-reach groups with special regard to immunisation programmes against hepatitis B.