Unexpected findings of hepatitis B and delta infection in northeastern Brazil: A public health alert.

INTRODUCTION AND OBJECTIVES: Research has shown that hepatitis B (HBV) and Delta virus (HDV) are a worldwide public health problem. This study aims to estimate the prevalence rates of HBV and HDV infection in five municipalities of Maranhão, Northeastern Brazil. MATERIALS AND METHODS: A total sample between 3856 and 4000 individuals. Questionnaires were used to register sociodemographic characteristics and factors associated with transmission. Patients were tested for hepatitis B virus surface antigen (HBsAg), anti-hepatitis B core antigen (anti-HBc), and antibodies against hepatitis Delta virus (anti-HDV). Factors associated with HBV were detected by means of multivariate Poisson regression. RESULTS: Overall, 3983 subjects were included. Ninety-two of the participants were HBsAg-positive (2.30%, 95% CI 1.80-2.80), and anti-HBc was detected in 1535 (38.50%, 95% CI 37-40). The factors associated with the presence of anti-HBc were: (1) Municipality (P<0.001); Age (P<0.001); School education (P<0.001); Illicit drug use (P=0.001); non-HBV vaccine (P=0.041). Among the HBsAg carriers, eight were anti-HDV-positive (8.69%, 95% CI 2.90-14.40). The most frequent HBV genotype was D4. The only HDV genotype was HDV-8. CONCLUSION: HBV exhibited intermediate endemicity in the studied region. Traditional factors were associated with exposure to the virus. The presence of the HDV was confirmed. The most frequent HBV and HDV genotypes were unlike the ones currently described in Brazil.

High prevalence of hepatitis B virus subgenotypes A1 and D4 in Maranhão state, Northeast Brazil.

In this study, we determined the prevalence of HBV subgenotypes in Maranhão state, located in northeastern Brazil, where the population is heterogeneous, with a high proportion of African descendants. HBV was detected in 119 of 133 (89.5%) chronic hepatitis B patients, including 103 (86.5%) who were HBeAg-negative. Using phylogenetic analysis of the S/Polymerase region of HBV DNA, subgenotype A1 was found to be the most prevalent (67%), followed by genotype D (28%; subgenotype D4 was detected in 24%, D3 in 3%, and D2 in 1%). Genotype F, clustering with subgenotype F2a, was found in six (5%) patients. The topology of the phylogenetic tree showed that HBV/A1 sequences did not cluster together, suggesting that more than one strain was introduced into Maranhão. On the other hand, HBV/D4 sequences formed a monophyletic cluster, suggesting a single entry of this strain in this population. This study showed that HBV/A1 was the only subgenotype of HBV/A present in the population from Maranhão and indicated that in this region HBV/A1 was not restricted to an Afro-descendant community where it was previously reported, but is widely distributed among general population of HBV chronic carriers. Unexpectedly, we found a high frequency of HBV subgenotype D4. Together with previously reported data on the distribution of HBV/D4 in the world, these findings suggest that this subgenotype was more prevalent in the African continent in the past and may have been introduced in Maranhão by means of the slave trade during the late XVIII century, when the largest number of African slaves arrived to this region.