title: Detection of hepatitis C virus subtypes 6a, 6n, 6w and mixed infections using a modified multiplex real-time polymerase chain reaction protocol.
abstract: OBJECTIVE
  In the past few years, many new subtypes in hepatitis C virus (HCV) genotype 6 have been identified. The aim of this study was to modify the multiplex real-time polymerase chain reaction (RT-PCR) protocol and use it to determine the HCV subtypes of a group of Taiwanese injection drug users (IDUs).
  
  
  METHODS
  We used 76 serum specimens collected in northern Taiwan in 2008. Multiplex RT-PCR was used for HCV subtyping among those serum samples having anti-HCV antibodies. Twenty cases were randomly selected for comparison with subtyping results from Inno-LiPa II tests and phylogenetic tree analysis using NS5B sequences.
  
  
  RESULTS
  Multiplex RT-PCR assays showed that 60.5% (46/76) of IDUs had single HCV infection. Three out of 76 (3.9%) had double HCV infection (1b/6a, 2a/2b and 2b/6a). Besides this, 27.6% (21/76) had no HCV signal. One IDU had subtype 6n and two had subtype 6w infection. Inno-LiPa II tests misclassified all 6n and 6w cases as 1b subtype.
  
  
  CONCLUSIONS
  Our modified multiplex RT-PCR protocol can be used to support molecular epidemiological studies and laboratory diagnoses of different HCV subtypes including genotype 6.
authors.affiliation: AIDS Prevention and Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yuan-Ming
authors.initials: YM
authors.lastname: Lee
authors.forename: Yen-Ju
authors.initials: YJ
authors.lastname: Chen
authors.forename: Cheng-Ming
authors.initials: CM
authors.lastname: Lee
authors.forename: Lou-Hui
authors.initials: LH
authors.lastname: Kuo
authors.forename: Wing-Wai
authors.initials: WW
authors.lastname: Wong
authors.forename: Yi-Ming Arthur
authors.initials: YM
authors.lastname: Chen
mesh_terms: D060005:Genotyping Techniques; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics; D006526:Hepatitis C / Q000175:diagnosis*; D006801:Humans; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*