Estudo epidemiológico e molecular da infecção pelo vírus da hepatite B em Afro-descendentes de comunidade isolada no Estado de Goiás (Kalungas)

• Autor(a) principal: MATOS, Márcia Alves Dias de
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1580
• topic: Hepatite B; prevalência; aspectos moleculares; afro-descendentes; Hepatitis B; prevalence; afro-Descendants; molecular aspects; CNPQ::CIENCIAS DA SAUDE::MEDICINA

Hepatitis B virus (HBV) infection occurs throughout the world. In Africa, this infection is highly endemic, with the majority of individuals becoming infected during childhood. Although Brazil has been globally considered a country of HBV intermediate endemicity, variable rates have been found in all five Brazilian regions and even inside the same region. This study aimed to investigate the epidemiological and molecular profile of the HBV infection among the Kalunga population in Goiás, Central Brazil, which is considered the largest Afro-Brazilian isolated community. A total of 878 individuals were interviewed about sociodemographic characteristics, risk factors and HBV vaccination. Blood samples were collected from all participants and serum samples were screened by enzyme-linked immunosorbent assay for the presence of HBsAg, anti-HBc and anti-HBs serological markers. HBsAg-positive samples were submitted to HBeAg and anti-HBe detection. HBsAg and anti-HBc positive samples were tested for HBV DNA detection by polymerase chain reaction and genotyping by subsequent restriction fragment length polymorphism (RFLP) analysis and nucleotide sequencing of preS/S region. The overall prevalence of HBV infection was 35.4% (95% CI: 32.3-38.7). HBsAg carrier rate was 1.8% (95% CI: 1.1- 3.0). Multivariate analysis of risk factors showed that increased age, male gender, illiteracy and history of multiple sexual partners were associated with this infection. Isolated anti-HBs was found in 301 (34.3%) individuals who were immune for hepatitis B. HBV DNA was detected in 75% (12/16) of the HBsAg positive samples, in 100% (2/2) of the HBeAg and in 83.3% (10/12) of the anti-HBe positive samples. An occult HBV infection rate of 1.7% (5/295) was found among anti-HBc positive individuals. All genotyped isolates belonged to genotype A by RFLP analysis. Nucleotide sequencing of preS/S region confirmed the circulation of genotype A (subgenotype Aa) in this community. The epidemiological findings indicate that preventive measures, such as additional health education and HBV vaccination programs, are needed to control HBV infection in this population. In addition, the molecular results suggest the introduction of genotype A, subgenotype Aa in Brazil from Africa during the slave trade.