title: 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.
authors.affiliation: Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany; Vietnam Military Medical University, Ha Noi, Viet Nam.
authors.forename: B T
authors.initials: BT
authors.lastname: Sy
authors.forename: H M
authors.initials: HM
authors.lastname: Nguyen
authors.forename: N L
authors.initials: NL
authors.lastname: Toan
authors.forename: L H
authors.initials: LH
authors.lastname: Song
authors.forename: H V
authors.initials: HV
authors.lastname: Tong
authors.forename: C
authors.initials: C
authors.lastname: Wolboldt
authors.forename: V Q
authors.initials: VQ
authors.lastname: Binh
authors.forename: P G
authors.initials: PG
authors.lastname: Kremsner
authors.forename: T P
authors.initials: TP
authors.lastname: Velavan
authors.forename: C-T
authors.initials: CT
authors.lastname: Bock
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006509:Hepatitis B / Q000150:complications*; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D003699:Hepatitis D / Q000821:virology*; D003698:Hepatitis Delta Virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D055815:Young Adult
chemical_list: D006514:Hepatitis B Surface Antigens; D012367:RNA, Viral
keywords: HDV genotype; HDV genotype mixture; HDV recombinant; Hepatitis D virus; phylogenetic analysis; variability