High rates of serological response to a modified hepatitis B vaccination schedule in HIV-infected adults subjects.

We evaluated a modified HBV regimen in a cohort of HIV-infected subjects in Rio de Janeiro, Brazil. HIV-infected subjects with no serologic evidences of previous hepatitis B infection were immunized with 4 doses (40 microg each) of recombinant hepatitis B vaccine given at 0, 1, 2 and 6 months. Blood samples were collected 1 month after the last dose and anti-HBs titers were measured. A protective antibody response was defined as an anti-HBs titer >or=10 mIU/mL. Forty-seven subjects (30 women, 17 men; mean age was 36 years, ranging from 21 to 58 years) were included in the final analysis. Median baseline CD4+ lymphocyte count was 402 cells/mm(3) and 33 subjects (70%) had an HIV viral load below 80 copies/mL. A protective antibody response was observed in 42 (89%) subjects. Thirty-seven (78%) and 28 (60%) patients developed anti-HBs titers higher than 100 mIU/mL and 1000 mIU/mL, respectively. 1 out of 5 non-responders (20%) had an HIV viral load below the detection limit, in contrast with 32 (76%) of those with an adequate serologic response (p=0.02). These findings suggest that 4-double dose alternative schedule may be considered to overcome the lower seroconversion rates observed with the standard regimens in HIV-infected subjects.

Trends in HCV prevalence, risk factors and distribution of viral genotypes in injecting drug users: findings from two cross-sectional studies.

In the last decade, a declining prevalence of HCV infection has been described in injecting drug users (IDUs) in different countries. This study is the first to assess temporal trends in drug-injecting patterns, HCV infection rates and viral genotype distribution in 770 Brazilian IDUs, recruited by two cross-sectional studies (1994-1997 and 1999-2001). A substantial decline in the prevalence of HCV infection was found over the years (75% in 1994 vs. 20.6% in 2001, P<0.001) that may be a consequence of the significant reduction in the overall frequencies of drug injection and needle-sharing, as well as the participation of IDUs in initiatives aimed at reducing drug-related harm. No trend was found in terms of viral genotype distribution. Despite the favourable scenario, preventive measures must be maintained, especially in vulnerable subgroups such as young or new injectors, where risky behaviours through direct and indirect sharing practices remain common.

Prevalence and risk factors for HBV, HCV and HDV infections among injecting drug users from Rio de Janeiro, Brazil

Viral hepatitis constitutes a major health issue, with high prevalence among injecting drug users (IDUs). The present study assessed the prevalence and risk determinants for hepatitis B, C and D viruses (HBV, HCV and HDV) infections among 102 IDUs from Rio de Janeiro, Brazil. Serological markers and HCV-RNA were detected by enzyme immunoassay and nested PCR, respectively. HCV genotyping was determined by restriction fragment length polymorphism analysis (RFLP). HBsAg, anti-HBc and anti-HBs were found in 7.8, 55.8 and 24.7 percent of IDUs, respectively. In the final logistic regression, HBV infection was independently associated with male homosexual intercourse within the last 5 years (odds ratio (OR) 3.1; 95 percent confidence interval (CI) 1.1-8.8). No subject presented anti-delta (anti-HD). Anti-HCV was detected in 69.6 percent of subjects, and was found to be independently associated with needle sharing in the last 6 months (OR 3.4; 95 percent CI 1.3-9.2) and with longer duration of iv drug use (OR 3.1; 95 percent CI 1.1-8.7). These data demonstrate that this population is at high risk for both HBV and HCV infection. Among IDUs from Rio de Janeiro, unprotected sexual intercourse seems to be more closely associated with HBV infection, whereas HCV is positively correlated with high risk injecting behavior. Comprehensive public health interventions targeting this population and their sexual partners must be encouraged

Distribution of HCV genotypes among different exposure categories in Brazil

Hepatitis C virus (HCV) infection is widespread and responsible for more than 60 percent of chronic hepatitis cases. HCV presents a genetic variability which has led to viral classification into at least 6 genotypes and a series of subtypes. These variants present characteristic geographical distribution, but their association with different responses to treatment with interferon and severity of disease still remains controversial. The aim of this study was to investigate the patterns of distribution of HCV genotypes among different exposure categories in Brazil. Two hundred and fifty anti-HCV positive samples were submitted to HCV-RNA detection by RT-PCR and their genotype was determined by restriction fragment length polymorphism (RFLP) analysis. In addition, the genotype/subtype of 60 samples was also determined by a reverse hybridization assay. HCV 1 was the most prevalent (72.0 percent), followed by type 3 (25.3 percent), HCV 2 (2.0 percent) and HCV 4 (0.7 percent). The HCV genotype distribution varied among the different exposure categories, with HCV 1 being more frequent among blood donors, hemophiliacs and hemodialysis patients. A high frequency of HCV 3 was observed in cirrhotic patients, blood donors from the South of Brazil and injecting drug users (IDUs). The general distribution of the HCV genotype in Brazil is similar to that in other regions of the world