Prevalence of hepatitis B virus and risk factors in Brazilian non‐injecting drug users

Non‐injecting drug users are at high‐risk for acquiring hepatitis B virus (HBV), although the factors contributing to this increased risk are not known. In the present study, the overall and occult HBV infection prevalence rates were determined in a large population of non‐injecting drug users in the Central‐West region of Brazil. HBV genotypes and predictors of infection were also identified. A total of 852 individuals in 34 drug treatment centers were interviewed, and their serum samples were tested for the presence of HBV markers by ELISA. HBsAg and anti‐HBc‐positive samples were tested for HBV DNA by PCR. Samples with HBV DNA were genotyped by restriction fragment length polymorphism (RFLP). The overall prevalence of HBV infection was 14% (95% CI: 11.7–16.5). A multivariate analysis of risk factors showed that age >30 years, non‐white race/ethnicity, duration of drug use >10 years, lifetime number of sexual partners >10, non‐use of condoms, and HCV and HIV status were associated significantly with HBV infection. Of the 9 (1%) HBsAg‐reactive samples, HBV DNA was present in 2/2 of HBeAg‐positive and in 5/7 anti‐HBe‐positive samples. An occult HBV infection rate of 2.7% (3/110) was found among anti‐HBc‐positive individuals. All HBV DNA‐positive samples were genotyped: seven were genotype A, two were genotype D, and one was genotype F. Finally, few individuals (8%) had serological evidence of a previous HBV vaccination. These findings indicate that preventive interventions are needed for both sexual and drug‐related high‐risk behavior. Additionally, non‐injecting drug users should be targeted for HBV vaccination. J. Med. Virol. 81:602–609, 2009 © 2009 Wiley‐Liss, Inc.