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.

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Intravenous drug injection has been reported as the main risk factor for hepatitis C virus (HCV) infection. The aim of the present study was to describe the prevalence and the epidemiological profile of HCV infection among abusers of illegal injected and non-injected drugs in 5%). Logistic regression analyses showed independent associations between HCV infection and intravenous drug use, imprisonment and increasing age. In the present study, inject-, imprisonment and increasing age. In the present study, injecting drug use was the factor most strongly associated to HCV infection and inhaling or sniffing did not represent an increased susceptibility to infection.Key words: epidemiology -hepatitis C virus -illicit drug users -HCV prevalence -HCV epidemiology Hepatitis C virus (HCV) is a common cause of liver disease and a major public health issue worldwide (Kew et al. 2004, Scheinmann et al. 2007. HCV is transmitted efficiently via the parenteral route, whereas transmission is less common due to sexual or perinatal contact. Estimates indicate that there are ~170 million people infected worldwide. In the West, the HCV-positive population ranges from less than 1-2% (Shepard et al. 2005).HCV is characterised by a high genetic variability and is classified into six major genotypes. Genotype 1 is the most prevalent worldwide, followed by genotypes 3 and 2 (Sablon & Shapiro 2004). In most Brazilian regions, genotype 1 is the etiologic agent in 60-75% of HCV infections (Paraná et al. 2000, Campiotto et al. 2005. Genotype 3 is the second-most prevalent strain and genotype 2 constitutes less than 5% of cases.Intravenous drug users are considered to be the main risk group for HCV infection and act as a reservoir for this blood-borne virus. Prevalence of anti-HCV antibodies among intravenous drug users ranges from 31-98% around the world and increases proportionally according to the duration of intravenous drug use (Memon & Memon 2002). Generally, genotypes 3a and 1a have been found more frequently in this group (Stark et al. 1995, Lanternier et al. 2007.The aim of this study was to estimate the prevalence of HCV infection and the main genotypes circulating among illicit drug users in the capital of the state of Mato Grosso (MT), Cuiabá, Central Brazil. We also tried to identify factors associated with HCV infection in this population. PATIENTS, MATERIALS AND METHODSA cross-sectional study was designed in order to assess illicit drug users (injecting and non-injecting) who are or have been receiving treatment either during day visits or while staying in rehabilitation centres in the city of Cuiabá in 2007.The eight main centres offering this service were included. A peculiarity of all of these centres is that they only treat male patients. Thus, female patients were not included. Four other centres that had a small number of individuals in treatment were not visited due to access and logistical difficulties.The volunteers were approached in their respective treatment centres. Those who agreed to participate were interviewed...