Prevalence of overt and occult hepatitis B virus infection among an incarcerated population of Central-Western Brazil.

Brazilian prison complexes are characterized by overcrowded cells and precarious conditions, leading to chronically low vacancy. Brazilian studies involving overt and occult infection (OBI) in this population are still scarce despite the vulnerability of people deprived of liberty to hepatitis B. Therefore, this study estimated the prevalence of HBV infection (overall and OBI) in individuals deprived of liberty in prisons in Central-Western Brazil. In addition, factors associated with HBV infection were evaluated. This cross-sectional study was conducted with a total of 1083 prisoners who were tested for serological hepatitis B markers and HBV DNA from 2017 to 2020. Factors associated with lifetime HBV infection were investigated using logistic regression. An overall prevalence of HBV infection of 10.1% (95% CI: 8.42-12.11) was detected. Only 32.8% (95% CI: 30.08-35.76) had isolated anti-HBs positivity (serological evidence of HBV vaccination). Indeed, more than half of the population was susceptible to HBV infection (57.1%; 95% CI: 54.15-60.13). HBV DNA was detected in one HBsAg-positive sample (n=1/9; 11%). Also, HBV DNA was detected in five HBsAg-negative samples (n=5/1074), resulting in a prevalence of 0.5% (95% CI: 0.15-1.08) for occult infection. After the multivariate analysis, sexual intercourse with a partner living with HIV was a predictor independently associated with HBV exposure (OR: 4.3; 95% CI: 1.26-14.55; p<0.020). These data demonstrate the need for preventive measures, mainly aimed at health education and better strategies for hepatitis B screening to control this infection in prisons more effectively.