title: High prevalence and significance of hepatitis D virus infection among treatment-naïve HBsAg-positive patients in Northern Vietnam.
abstract: BACKGROUND
  Hepatitis D virus (HDV) infection is considered to cause more severe hepatitis than hepatitis B virus (HBV) monoinfection. With more than 9.5 million HBV-infected people, Vietnam will face an enormous health burden. The prevalence of HDV in Vietnamese HBsAg-positive patients is speculative. Therefore, we assessed the prevalence of HDV in Vietnamese patients, determined the HDV-genotype distribution and compared the findings with the clinical outcome.
  
  
  METHODS
  266 sera of well-characterized HBsAg-positive patients in Northern Vietnam were analysed for the presence of HDV using newly developed HDV-specific RT-PCRs. Sequencing and phylogenetic analysis were performed for HDV-genotyping.
  
  
  RESULTS
  The HDV-genome prevalence observed in the Vietnamese HBsAg-positive patients was high with 15.4% while patients with acute hepatitis showed 43.3%. Phylogenetic analysis demonstrated a predominance of HDV-genotype 1 clustering in an Asian clade while HDV-genotype 2 could be also detected. The serum aminotransferase levels (AST, ALT) as well as total and direct bilirubin were significantly elevated in HDV-positive individuals (p<0.05). HDV loads were mainly low (<300 to 4.108 HDV-copies/ml). Of note, higher HDV loads were mainly found in HBV-genotype mix samples in contrast to single HBV-infections. In HBV/HDV-coinfections, HBV loads were significantly higher in HBV-genotype C in comparison to HBV-genotype A samples (p<0.05).
  
  
  CONCLUSIONS
  HDV prevalence is high in Vietnamese individuals, especially in patients with acute hepatitis B. HDV replication activity showed a HBV-genotype dependency and could be associated with elevated liver parameters. Besides serological assays molecular tests are recommended for diagnosis of HDV. Finally, the high prevalence of HBV and HDV prompts the urgent need for HBV-vaccination coverage.
authors.affiliation: Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany ; Department of Pathophysiology, Vietnam Military Medical University, Ha Noi, Ha Dong, Viet Nam.
authors.forename: Bui Tien
authors.initials: BT
authors.lastname: Sy
authors.forename: Boris A
authors.initials: BA
authors.lastname: Ratsch
authors.forename: Nguyen Linh
authors.initials: NL
authors.lastname: Toan
authors.forename: Le Huu
authors.initials: le H
authors.lastname: Song
authors.forename: Christian
authors.initials: C
authors.lastname: Wollboldt
authors.forename: Agnes
authors.initials: A
authors.lastname: Bryniok
authors.forename: Hung Minh
authors.initials: HM
authors.lastname: Nguyen
authors.forename: Hoang Van
authors.initials: HV
authors.lastname: Luong
authors.forename: Thirumalaisamy P
authors.initials: TP
authors.lastname: Velavan
authors.forename: Heiner
authors.initials: H
authors.lastname: Wedemeyer
authors.forename: Peter G
authors.initials: PG
authors.lastname: Kremsner
authors.forename: C-Thomas
authors.initials: CT
authors.lastname: Bock
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001663:Bilirubin / Q000378:metabolism; D005260:Female; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000378:metabolism*; D003699:Hepatitis D / Q000453:epidemiology* / Q000276:immunology / Q000378:metabolism / Q000821:virology*; D003698:Hepatitis Delta Virus / Q000276:immunology / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014744:Vietnam / Q000453:epidemiology; D055815:Young Adult
chemical_list: D006514:Hepatitis B Surface Antigens; D001663:Bilirubin