Overt and occult hepatitis B virus infection among treatment-naïve HIV-infected patients in Brazil.

Although hepatitis B virus (HBV) and human immunodeficiency virus (HIV) co-infection is common, only few data are available on HBV among HIV patients including occult hepatitis B infection (OBI), regardless of serological markers. This study aims to determine the prevalence of OBI and overall HBV infection, associated factors, HBV genotypes, and surface (S) gene mutations in a population of treatment-naïve HIV-infected patients in Brazil. A cross-sectional study was conducted in treatment-naïve HIV-infected patients in Central Brazil. All samples were tested for HBV serological markers and HBV DNA. Sequence analysis of the S gene and overlapping polymerase gene was preformed. Overall, 25.1% (127/505) of the patients had markers of current or previous HBV infection, which was associated with age over 40 years, history of injection drug use, and homosexual sex. The hepatitis B surface antigen (HBsAg) seroprevalence was 4.9% (25/505). HBV DNA was detected in 39 out of 505 patients: 20 of them were HBsAg-positive and 19 were HBsAg-negative, resulting in an OBI prevalence of 3.8%. Patients with OBI had significantly higher HCV seropositivity rate compared to HBsAg-positive patients. Sequencing of the S gene revealed Y100C, T131N, and D144A mutations. One patient had the M204I and L180M drug-resistance mutations (polymerase). HBV genotypes A (A1, A2), D (D2, D3), and F (F2) were identified. In conclusion, OBI represented almost half of all HBV infections with detectable HBV DNA, suggesting that hepatitis B diagnosis in HIV patients should include in addition to serological markers the detection of HBV DNA.