Dados do Trabalho

Título

Genotypes and Clinically Relevant Mutations of Hepatitis B Virus in a Population of Foreign Immigrants in Brazil

Introdução

Hepatitis B is a prevalent viral infection in humans. Hepatitis B virus (HBV) has a high genetic variability, and is phylogenetically classified into ten genotypes (A-J) and several subgenotypes, based on the nucleotide diversity of the complete genome. Frequencies of clinically relevant mutations vary significantly between HBV (sub)genotypes, which have a characteristic ethno-geographical distribution, reflecting historical patterns of human migrations. However, recent globalization trends and increased human mobility contribute to changes in the geographical dispersion of HBV (sub)genotypes worldwide and introduction of exotic strains in destination territories. Foreign immigrants under vulnerable conditions are a growing group in Brazil. So far, there is no data in the country about the molecular characteristics of HBV in this population.

Objetivo (s)

The present study aims to identify the circulating HBV (sub)genotypes and the clinically relevant mutations in a population of foreign immigrants residing in Goiás, Central-West Brazil.

Material e Métodos

A total of 102 anti-HBc positive subjects (24 HBsAg positive) were included in this study. HBV DNA was extracted from serum, S and C genomic regions were amplified by nested PCR and further sequenced. Phylogenetic analysis was performed using MEGA X software.

Resultados e Conclusão

The countries of origin were Haiti (79.4%), Guinea Bissau (11.8%), Venezuela (7.8%), and Colombia (1%). HBV DNA was detected in 15 (14.7%) subjects. Interestingly, HBV DNA was detected in three HBsAg negative individuals, resulting in a prevalence of occult HBV infection of 3.8%. HBV subgenotypes A1 (n=6, 40%), A2 (n=1, 6.7%), A5 (n=6, 40%), F2 (n=1, 6.7%), and F3 (n=1, 6.7%) were identified. HBV/A1-infected subjects were from Haiti (n=5) and Guinea- Bissau (n=1), while those infected with HBV/A2, HBV/A5, HBV/F2, and HBV/F3 were from Haiti (A2 and A5) and Venezuela (F2 and F3). To our knowledge, this is the first detection of subgenotype A5 in Brazil. No immune escape mutation was detected. Two out of six (33.3%) HBV/A5 core sequences showed the A1762T/G1764A double mutation, which has been associated with liver cancer development. This study will contribute to public health strategies for this population as well as to the identification of HBV exotic strains in Brazil, which may affect the diagnosis, immunization, treatment, and prognosis of hepatitis B in the country.

Palavras-chave

Hepatitis B virus, phylogenetic analysis, molecular epidemiology, immigration

Agradecimentos

LVPM and UFG; CAPES and FAPERJ