title: [Study on the genotypic characteristics of Japanese encephalitis virus and serology in the healthy population of Zhejiang province, 2012-2013].
abstract: OBJECTIVE
  To understand the genotypic characteristics and the neutralizing antibody levels of Japanese encephalitis virus (JEV) and Japanese encephalitis (JE) in both vector mosquitoes and in healthy people of Zhejiang province.
  
  
  METHODS
  Virus was isolated from mosquitos sampled from the Monitoring Stations located in Xianju county during 2012 to 2013. Phylogenetic and homological studies were carried out on the E gene. A total of 1 263 blood specimens from 642 healthy people were collected before and after the seasons of JE epidemics. JEV neutralizing antibody was detected by the micro-neutralization test.
  
  
  RESULTS
  Twenty-five JEV strains were isolated from a total of 11 650 mosquitoes. The identity of nucleotide appeared as 87.8%-99.7% both from 2012 to 2013 and from 1982 to 2010 while as 87.7%-88.0% with vaccine strain SA14-14-2, in Zhejiang. The phylogeny tree of E gene indicated that the newly isolated virus belonged to genotype I but no mutation of amino acid sequence coding conformational epitope was identified in the envelop protein. Both positive rates and the geometric mean titer (GMT) of neutralizing antibody in healthy people were 31.5%-42.0% and 1 : 2.56-1 : 3.53 in Xianju county, during 2012 and 2013, respectively. Both of the two positive rates (χ(2)≤1.76, P > 0.05) and the two GMTs (u≤0.64, P > 0.5) for antibodies pre or post the epidemic season did not show significant differences.
  
  
  CONCLUSIONS
  JEV isolated in Xianju during 2012 and 2013 belonged to genotype I. The positive rates of JEV neutralizing antibody from healthy people in Xianju were less than 42.0%, which showed no significant differendes pre or post JE epidemic season.
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China. Email: jyyan@cdc.zj.cn.
authors.forename: Juying
authors.initials: J
authors.lastname: Yan
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors.forename: Jinren
authors.initials: J
authors.lastname: Pan
authors.affiliation: Xianju County Center for Disease Control and Prevention.
authors.forename: Yijian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors.forename: Jiayue
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Xianju County Center for Disease Control and Prevention.
authors.forename: Hongnian
authors.initials: H
authors.lastname: Ni
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood*; D002681:China; D009033:Culicidae / Q000821:virology; D004199:Disease Vectors; D004664:Encephalitis Virus, Japanese / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D004672:Encephalitis, Japanese / Q000821:virology; D000939:Epitopes; D005838:Genotype; D006801:Humans; D009500:Neutralization Tests; D010802:Phylogeny
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000939:Epitopes