title: [Molecular epidemiological study of measles viruses isolated in Qinghai Province during 2000-2011].
abstract: OBJECTIVE
  To carry out the molecular epidemiological study of the wild-type measles virus isolated in Qinghai Province during 2000-2011, and provide a scientific basis for the measles elimination.
  
  
  METHODS
  Measles viruses were isolated using B95a cell line or Vero/SLAM cell line from throat swabs collected from suspected measles cases during measles outbreak and sporadic in 6 prefectures during 2000-2011. The fragment of 696 nucleotides of N gene carboxy terminal was amplified by using RT-PCR methods. The PCR products were sequenced and analyzed. The phylogenetic tree was conducted with the viruses isolated in viruses from other province.
  
  
  RESULTS
  Total 19 measles viruses were isolated during 2000-2011 in Qinghai province and all belong to genotype H1a. The results of phylogenetic tree showed that viruses in 2000-2005 and in 2009-2011 were distributed in two different lineages, and it revealed that these strains belonged to at least 2 viral transmission chains and the viruses circulated during 2000-2005 were not detected after 2005.
  
  
  CONCLUSIONS
  Genotype H1a was the predominant genotype circulated in Qinghai province during 2000-2011. Qinghai measles virus strains had not evolved independently, but coevolved with the measles virus strains in other provinces in mainland China. The variation of important amino acid sites of measles virus should be continuous monitored and provide the scientific strategy for the measles elimination.
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Fan
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Zhuo-Ma
authors.initials: ZM
authors.lastname: Ba
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Sheng-Cang
authors.initials: SC
authors.lastname: Zhao
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Yi
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Shuang-Ying
authors.initials: SY
authors.lastname: Jiang
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Wang
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining 810007, China.
authors.forename: Wen-Bo
authors.initials: WB
authors.lastname: Xu
mesh_terms: D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D005838:Genotype; D006801:Humans; D008457:Measles / Q000453:epidemiology / Q000821:virology*; D008459:Measles virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny