Caracterização dos genótipos do vírus da hepatite b em pacientes atendidos no programa de hepatites virais do núcleo de medicina tropical – UFPA, Belém - Pará

Abstract

The hepatitis B virus belongs to the genus Orthohepdnavirus and Hepadnaviridae family, comprising a DNA virus capable of infecting mammalian hepatotropic. Classified into 10 genotypes (A-J) and many different subgenotypes, studies suggest that they may influence the severity of the disease, response to treatment and vaccine response. Genotypes and subgenotypes HBV has a wide distribution, some being restricted to certain geographic regions, while others show a worldwide distribution. It is found in different regions of Brazil with prevalence of genotypes A, D and F. This study aimed to identify genotypes and subgenotypes of hepatitis B virus among patients treated at the Tropical Medicine Center - UFPA, in the city of Belém, state Pará, from January 2011 to December 2015. A total of 1274 patients treated at the NMT-UFPA in the period, were selected for the study 222 patients of both sexes, with positive serology for HBsAg and / or anti-HBc. The samples were subjected to molecular biology, PCR "in house" and multiplex PCR to detect viral DNA and genotyping, and then the sequencing for confirmation and determination of viral subgenotypes. In 65 of the 222 samples was detected the presence of HBV DNA, but only 63 samples were satisfactory after the result of sequencing, which were identified the presence of genotypes A (46/63), especially the subgenotype A1 (36/46) followed by subgenotype A2 (10/46), and genotype F (17/63) and only detected subgenotype F2 (17/17) circulating in this population. The average age of the patients was 38 years, predominantly male, and most natural state of Pará patients. Some risk factors have been identified among the population studied, and not using a condom during sex the most predominant. Comparing the presence of viral DNA with serology for HBsAg marker is shown a picture that suggests the presence of occult hepatitis among the patients treated. The results found in this study are consistent with what is reported in other studies in Brazil.