title: [The velocity of HCV subtype 6a transmission in southwest China].
abstract: OBJECTIVE
  To estimate the velocity of HCV subtype 6a transmission in Southwest China.
  
  
  METHODS
  The HCV CE1 region from 61 patients infected with HCV genotype 6 were amplificated by RT-PCR and sequenced. The subtypes were identified, and the period of HCV 6a strains originated in southwest china was estimated by using molecular clock phylogenetic analysis. The velocity of HCV subtype 6a transmission in southwest China was estimated by BEAST v1.6.1 and Tracer v1.5 software theoretically.
  
  
  RESULTS
  Most of HCV 6a strains distributed in Southwest China origine around the year 1968 and at last 4 epidemic strains existed. The earlier origine strains could be isolated both in intravenous drug users (IDU) and non-IDU patients. After 1997, the HCV 6a strains transmission in southwest China accelerated and the trend intensified in 2007.
  
  
  CONCLUSIONS
  HCV 6a strains spread fastly both in IDU and non-IDU patients, which might be the main HCV subtype distributed in Southwest China in the future.
authors.affiliation: PLA Institute of Infectious Diseases, the Third Military Medical University, Chongqing, China.
authors.forename: Guo-hu
authors.initials: GH
authors.lastname: Hong
authors.forename: Zhao-xia
authors.initials: ZX
authors.lastname: Tan
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.forename: Qing
authors.initials: Q
authors.lastname: Mao
mesh_terms: D002681:China / Q000453:epidemiology; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D006801:Humans; D008297:Male; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics
chemical_list: D012367:RNA, Viral