Dados do Trabalho

Título

ANALYSIS OF THE GENETIC DIVERSITY OF HEPATITIS DELTA VIRUS CIRCULATING IN BRAZIL BETWEEN 2013 AND 2015

Introdução

Hepatitis D virus (HDV) is a defective virus dependent on the hepatitis B virus (HBV). Despite being a crucial aspect, the genotypic characterization of HDV is not well established. Therefore, as new genomic data become available, new classification proposals appear, and the origin of the virus is better understood. Currently, HDV is divided into 8 genotypes and subgenotypes with distinct geographic distributions worldwide. In Brazil, genotypes 1 and 3 predominate, however, there are few available studies approaching viral genetic variability, especially about the complete genome.

Objetivo(s)

In this context, this work seeks to understand the genetic variability and to contribute to the evolutionary history of HDV in Brazil.

Material e Métodos

It was performed using 40 anti-HDV positive sera from Brazil, collected between 2013 and 2015. Of the total, 11 HDV RNA positive samples were amplified by RT-PCR of overlapping fragments, covering the complete genome. The samples still had a ~900 base pair genomic region of HBV amplified by PCR. The amplicons were sequenced by the Sanger method, followed by phylogenetic and phylogeographic analysis.

Resultados e Conclusão

The phylogeny showed the circulation of HDV-3 (9/11; 81,8%), HDV-5 (1/11; 9,1%) and HDV-8 (1/11; 9,1%). Most HDV-3 samples (8/9;88.9%) were found in the endemic North region, while one was found in Central-West Brazil, a non-endemic area. HDV-5 and 8, whose circulation is usually restricted to African countries, were found in São Paulo, a cosmopolitan city from Southeast Brazil. Furthermore, phylogenetic analysis of HDV-8 strains indicated that the sample determined in our study, together with previously reported sequences from Brazil, formed a highly supported monophyletic clade, probably representing a new HDV-8 subgenotype. The association between HDV/HBV genotypes indicated the presence of coinfection between HDV-3/HBV-F2 (5/11; 41.7%), HDV-3/HBV-A1 (2/11; 18.2%), HDV-3/HBV-D3 (1/11; 9.1%), HDV-3/ HBV-D4 (1/11; 9.1%), HDV-5/HBV-E (1/11; 9.1%) and HDV-8/HBV-E (1/11; 9.1%). The HBV genotypes commonly found in Brazil, HBV-A, HBV-D and HBV-F, were detected in co-infections with HDV-3, endemic in the country. However, HBV-E, originating from Africa, was found in coinfection with HDV-5 and HDV-8, suggesting that such genotypes may have been imported from African countries. Such genotypes rarely reported in Brazil demonstrate the importance of epidemiological surveillance for monitoring the entry and dispersal of HDV viral variants throughout the country.

Palavras-chave

HDV