title: Laboratory diagnosis of vaccine-associated measles in Zhejiang Province, China.
abstract: OBJECTIVE
  Along with the improving vaccine coverage, suspected vaccine-associated measles has been reported in Zhejiang Province, China. In order to maintain the accuracy of the measles surveillance system, it is critical to discriminate between measles vaccine and wild-type virus.
  
  
  METHODS
  Eight suspected cases of vaccine-associated measles were reported in Zhejiang Province during 2011 and 2014. Sera collected within 4 days and throat swabs collected within 6 days after rash onset were tested with immunoglobulin M and measles virus (MeV) RNA to confirm MeV infection. In order to further identify the vaccine-associated cases, throat swabs with positive MeV RNA were tested using an allelic discrimination real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assay developed in this study, RT-PCR-restriction fragment length polymorphism (RFLP) recommended by the National Measles Laboratory, and RT-PCR followed by sequencing and genotyping.
  
  
  RESULTS
  Combining anti-measles immunoglobulin M and RNA testing, eight cases were confirmed as MeV infection. Of the eight, two were identified as vaccine-associated cases by the allelic discrimination rRT-PCR assay, and one was identified by RT-PCR-RFLP. Subsequent sequencing and genotyping confirmed that the sequences of the two cases were identical to that of the Chinese vaccine strain. The developed allelic discrimination rRT-PCR was 10 times more sensitive than the RT-PCR-RFLP assay when RNA standards generated from three genotypes of MeV were tested.
  
  
  CONCLUSIONS
  Vaccine-associated measles has been identified in Zhejiang. The developed allelic discrimination rRT-PCR assay is rapid and sensitive, which will facilitate the surveillance for vaccine-associated measles.
authors.affiliation: Key Laboratory of Emergency Detection for Public Health of Zhejiang Province, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China.
authors.forename: Chang-Ping
authors.initials: CP
authors.lastname: Xu
authors.affiliation: Key Laboratory of Emergency Detection for Public Health of Zhejiang Province, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China.
authors.forename: Min-Hong
authors.initials: MH
authors.lastname: Li
authors.affiliation: Key Laboratory of Emergency Detection for Public Health of Zhejiang Province, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China.
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: He
authors.affiliation: Key Laboratory of Emergency Detection for Public Health of Zhejiang Province, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China.
authors.forename: Yi-Yu
authors.initials: YY
authors.lastname: Lu
authors.affiliation: Key Laboratory of Emergency Detection for Public Health of Zhejiang Province, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China. Electronic address: fengyanzjh@aliyun.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D019411:Clinical Laboratory Techniques / Q000379:methods*; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008457:Measles / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology*; D008458:Measles Vaccine / Q000009:adverse effects* / Q000235:genetics / Q000276:immunology; D008459:Measles virus / Q000145:classification / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M; D008458:Measles Vaccine; D012367:RNA, Viral
keywords: allelic discrimination; measles virus; real-time reverse transcriptase polymerase chain reaction; vaccine-associated measles