Identification of a natural intergenotypic recombinant hepatitis delta virus genotype 1 and 2 in Vietnamese HBsAg‐positive patients

Abstract

Hepatitis D virus (HDV) infection is acquired as a co- /superinfection of Hepatitis B virus (HBV) and can modulate the pathophysiology of chronic hepatitis B and related liver diseases including hepatocellular carcinoma. Among the eight distinct HDV genotypes reported, relatively few studies have attempted to investigate the prevalence of HDV mixed genotypes and RNA recombination of HDV. With a recorded prevalence of 10-20% HBV infection in Vietnam, this study investigated the HDV variability, HDV genotypes and HDV recombination among twenty-one HDV isolates in Vietnamese HBsAg-positive patients. HDV subgenomic and full-length genome sequences were obtained using newly established HDV-specific RT-PCR techniques. The nucleotide homology was observed from 74.6% to 99.4% among the investigated full-length genome of the HDV isolates. We observed HDV genotype 1 and HDV genotype 2 in the investigated Vietnamese patients. Although no HDV genotype mixtures were observed, we report here a newly identified recombinant of HDV genotypes (HDV 1 and HDV 2). The identified recombinant HDV isolate C03 revealed sequence homology to both HDV genotype 1 (nt1 to nt907) and HDV genotype 2 (nt908 to nt1675; HDAg coding region) with a breakpoint at nt908. Our findings demonstrate the prevalence of intergenotypic recombination between HDV genotypes 1 and 2 in a Vietnamese HBsAg-positive patient. Extended investigation on the distribution and prevalence of HDV, HDV mixed genotypes and recombinant HDV genotypes in a larger Vietnamese population offers vital insights into understanding of the micro-epidemiology of HDV and subsequent pathophysiology in chronic HBV- /HDV-related liver diseases.

High Prevalence of Hepatitis Delta Virus among Persons Who Inject Drugs, Vietnam

“…This study, the previous report from the NIHE laboratory ( 7 ), and data from Sy et al ( 8 , 9 ) indicate that HDV is highly prevalent in Vietnam, particularly in the northern part of the country, contrary to previous reports ( 5 , 6 , 10 ). In particular, our findings indicate that increased efforts are needed to improve HBV vaccination rates among PWIDs and others with risk factors for infection.…”

Prevalence and genotype distribution of hepatitis delta virus among chronic hepatitis B carriers in Central Vietnam

“…For detecting HDV RNA genomes, primers HDV57-F and HDV60-R were used for first PCR round, HDV48-F and HDV54-R were used for nested PCR [34]. ( b ) For HDV genotyping, primers HDV04-F and HDV05-R were used for the first round, primers HDV06-F and HDV07-R were used for nested PCR [31].…”

Hepatitis delta virus: From biological and medical aspects to current and investigational therapeutic options

“…Recombination was firstly suggested from a patient sample analysis in 1999, then confirmed to occur in mixed genotype infections, both in vivo and in vitro, and recently re-visited in a patient suffering from acute hepatitis in Vietnam (135)(136)(137). Template-switching driven by the host RNA polymerase has been proposed as the most likely mechanism of HDV RNA recombination (138,139).…”