Prevalence, incidence and associated factors for HBV infection among male and female prisoners in Central Brazil: A multicenter study.

BACKGROUND: Prison populations are at high risk for hepatitis B virus (HBV) infection. The aim of this study was to assess the prevalence, incidence, HBV associated factors and circulating genotypes/subtypes. METHODS: A total of 3,368 prisoners from 12 closed prisons were randomly recruited for a cross-sectional study. In addition, a cohort study was conducted 12 months later and included 1,656 individuals. Participants underwent an interview and blood collection for the detection of HBV serological markers and HBV-DNA phylogenetic analysis. RESULTS: HBV exposure (anti-HBc+) was 9.8% (95% CI: 8.8-10.8); 11.2% were female and 9.6% were male. HBsAg+ was 0.6%. Only 31.4% of the participants had HBV vaccination-like profile (anti-HBs+ alone; 30.4% male vs. 36.8% female; p=0.004). Most individuals were susceptible to HBV (60.2% female vs. 52.2% male, p=0.001). HBV isolates were classified as genotypes A (45.4%), D (27.3%) and F (27.3%). In males, HBV exposure was associated with increased age. Male prisoners had more evidence of HCV/HBV co-infection (10.7%) than females (3.4%) and the frequency of Treponema pallidum infection among prisoners who had been exposed to HBV was higher in female prisoners when compared with male (39.7% vs. 19.1%). The incidence of HBV was 0.18/100 person-years (95% CI: 0.12%-0.25%). CONCLUSIONS: Our results indicate a high prevalence of HBV exposure in prisoners. Despite the low incidence of this infection, the occurrence of new cases indicates the need to implement preventive measures.

Epidemiological study of hepatitis B virus among prisoners with active tuberculosis in Central Brazil.

BACKGROUND: Due to environmental and social conditions inherent to incarceration, tuberculosis (TB) and hepatitis B virus (HBV) are major diseases among prison inmates. OBJECTIVE: To determine overall and occult HBV infection (OBI) prevalence rates, risk factors and genotype distribution among inmates with active TB. STUDY DESIGN: A cross-sectional study was conducted among 216 inmates with active TB recruited at the largest prisons in Campo Grande, Mato Grosso do Sul, Central Brazil. The participants were interviewed and tested for the presence of serological markers for HBV infection. RESULTS: The overall prevalence of HBV infection (total hepatitis B core antibodies) was 10.2% (95%CI 6.2-14.2). HBV surface antigen (HBsAg) prevalence was 1.4% (3/216). HBV DNA was detected in all three HBsAg-positive samples and in 10.5% (2/19) of the anti-HBc-positive samples (OBI), giving a HBV-TB co-infection prevalence of 2.3% (5/216). A multivariate analysis of risk factors showed that history of sharing cutting instruments, length of incarceration and homosexual sex were associated with HBV infection. CONCLUSION: Our findings indicate that HBV remains an important public health concern among prison inmates and active TB-HBV co-infection needs to be addressed for effective treatment.

Prevalence of hepatitis B virus infection among tuberculosis patients with or without HIV in Goiânia City, Brazil.

BACKGROUND: Hepatitis B virus (HBV) and tuberculosis (TB) represent major public health problems. There is currently little data on HBV infection among TB patients with and without human immunodeficiency virus (HIV). OBJECTIVES: To assess HBV prevalence among TB patients with and without HIV. STUDY DESIGN: From April 2008 to March 2010, a cross-sectional study was conduct among TB patients attended at a reference hospital in Goiânia City, Brazil. The participants were tested for serological markers of HBV infection and HIV antibodies. HBV DNA was detected in HBsAg-positive samples, and also in HBsAg-negative/anti-HBc-positive samples to look for HBV occult infection. RESULTS: Of 425 patients, 402 (94.6%) agreed to participate in the study. The overall prevalence of HBV (HBsAg and/or anti-HBc positive) and HIV infections were 25.6% (103/402) and 27.6% (111/402), respectively. A higher HBV infection rate was found among HIV-infected patients (36.9%; 41/111) compared to patients infected with TB only (20.0%; 57/285). A multivariate analysis of risk factors showed that age ≥ 50 years (p=0.03), non-injecting (p<0.01) and injecting (p<0.01) drugs use were associated with HBV infection. Among the HBsAg-positive samples (n=13), HBV DNA was detected in 10 (76.9%) samples. Of the 90 anti-HBc-positive samples, 13 were HBV DNA positive (with very low levels) resulting in an occult HBV infection rate of 14.4%. PCR-RFLP was successfully performed in 20 HBV DNA-positive samples: 15 were genotype A and 5 were genotype D. CONCLUSIONS: HBV infection was common, particularly among this with HIV infection.

Molecular epidemiology of hepatitis B virus in an isolated Afro-Brazilian community.

This study was conducted in an Afro-Brazilian, slave-descendant community with high (42.4%) hepatitis B virus (HBV) prevalence. Twenty (8.4%) out of the 239 subjects under study were HBsAg-positive, and HBV-DNA was detected in 59 (25%) individuals. A high rate (18.3%) of occult infection was therefore observed that was associated to low HBV loads (mean, 1.8 x 10(4) copies/ml) and to a specific amino acid substitution (C100Y) in the small surface antigen. Genotyping of 50 isolates showed that 43 (86%) were of subgenotype A1, one (2%) from subgenotype A2, and five (10%) from subgenotype D. Mixed genotypes A1 and E were observed in one (2%) sample. The genetic distance (0.8 +/- 0.3%) among the HBV/A1 isolates from the community was smaller than the intragroup divergence among A1 isolates from Brazil as a whole, but it was similar to that found between A2 isolates from different countries, suggesting that HBV/A1 was introduced in the community through different sources. The substitution W501R (polymerase), previously reported only in Gambia, was observed in 46% of the HBV/A1 isolates. The precore/core promoter region of HBsAg-positive isolates showed several substitutions that could explain the anti-HBe phenotype found in 18 of 20 (90%) of the HBsAg-positive subjects.