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.

Mutation in the S gene a determinant of the hepatitis B virus associated with concomitant HBsAg and anti-HBs in a population in Northeastern Brazil.

Mutations in the a determinant of S gene may develop co-existence of hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) in the serum of infected hepatitis B virus (HBV) individuals. Mutations in this region may change the antigenicity of HBsAg, which in turn, lead to escape of neutralizing action of anti-HBs antibodies. This study identified individuals with concomitant HBsAg and anti-HBs serological markers in individuals of Maranhão, Northeastern Brazil. Samples from a population-based study were evaluated for HBsAg, anti-HBs, and anti-HBc, and those that tested positive for simultaneous HBsAg and anti-HBs were submitted to HBV DNA quantification and S gene characterization by Sanger sequencing. Mutations were investigated in the a determinant located in major hydrophilic region (MHR) of the S gene. Among 3,984 samples analyzed, 92 (2.3%) were positive for HBsAg and three had the atypical HBsAg and anti-HBs-positive profile (3.26%). The frequency of HBsAg and anti-HBs co-existence was similar to previous studies. Only one individual harbored mutation in the S gene a determinant associated with this profile. Little is known about this phenomenon; however, studies as ours may contribute for future enlightenment of this important issue. J. Med. Virol. 89:458-462, 2017. © 2016 Wiley Periodicals, Inc.