Rastreamento sorológico e molecular do vírus da hepatite B em homens que fazem sexo com homens em Goiânia-Goiás, utilizando o método respondent-driven sampling (RDS)

• Ano de defesa: 2017
• Autor(a) principal: Oliveira, Marina Pedroso de
• Orientador(a): Martins, Regina Maria Bringel
• Banca de defesa: Martins, Regina Maria Bringel, Castro, Ana Rita Coimbra Motta de, Lago, Bárbara Vieira, Teles, Sheila Araújo, Aires, Rodrigo Sebba
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Medicina Tropical e Saúde Publica (IPTSP)
• Departamento: Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG)
• País: Brasil
• Palavras-chave em Português: Hepatite B; HSH; Epidemiologia; Vacinação; Genótipos; Mutações
• Palavras-chave em Inglês: Hepatitis B; MSM; Epidemiology; Vaccination; Genotypes; Mutations
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::MICROBIOLOGIA
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/7001

Men who have sex with men (MSM) are more vulnerable to hepatitis B virus (HBV) infection when compared to the general population. In Brazil, the epidemiological profile of hepatitis B in MSM is still poorly understood. This study aimed to estimate the prevalence of HBV infection in MSM in Goiânia-Goiás and to analyze the associated factors, perform a molecular characterization of the viral isolates, as well as to investigate the vaccine situation against hepatitis B in this population. A cross-sectional study was conducted among MSM in the City of Goiânia, Central Brazil. From March to November 2014, a total of 522 participants were recruited using respondent-driven sampling (RDS). After signing the consent form, MSM were interviewed and a blood sample was collected. All samples were tested for HBV serological markers and HBV DNA. HBV isolates were sequenced for the determination of HBV genotypes and subgenotypes by phylogenetic analysis and for identification of mutations in viral genome. Data were analyzed using the RDSAT and SPSS programs. The overall prevalence of HBV infection (presence of anti-HBc marker) was 15.4% (95% CI: 8.7-25.8) and the rate of HBsAg carriers was 0.6% (95% CI: 0.2-1.6). Age over 25 years old, receptive anal intercourse, previous sex with women, and history of sexually transmitted infection (STI) were factors associated with HBV infection. Viral DNA was detected only in HBsAg-positive individuals, and occult HBV infection was not observed in the study population. HBV isolates were classified into genotype A (subgenotypes A1 and A2).Mutations in the S (T131N), basal core promoter (BCP) (A1762T/G1764A) and Pre-C/C (G1862T/G1888A and G1862T) regions of the HBV genome were identified. About 40% (95% CI: 32.3-48.8) of the participants had serological evidence of previous HBV vaccination (reactive for isolated anti-HBs), while 76.2% reported having previously received the vaccine. In addition, 44.3% (95% CI: 36.1-52.9) of MSM were susceptible to HBV infection. A greater frequency of positivity for anti-HBs alone was observed among MSM up to 25 years old, followed by declining vaccination with increasing age. By contrast, an increase in HBV infection with increasing age was found. HBV vaccination was associated with unprotected anal intercourse and history of STI (with a borderline p-value). In this study, we observed a poor agreement when comparing the self-reported and serologic evidence of HBV vaccination (k = 0.17). These results reveal a high overall prevalence of HBV infection in the study population associated with sexual risk behaviors, and in contrast, a low frequency of hepatitis B vaccination, evidencing a need for public health strategies to increase vaccine coverage in MSM, in addition to monitoring HBV carriers.