title: Emergence of dengue virus 4 genotype II in Guangzhou, China, 2010: survey and molecular epidemiology of one community outbreak.
abstract: BACKGROUND
  The re-emergence of dengue virus 4 (DENV-4) has become a public health concern in South America, Southeast Asia and South Asia. However, it has not been known to have caused a local outbreak in China for the past 20 years. The purpose of this study was to elucidate the epidemiology of one local community outbreak caused by DENV-4 in Guangzhou city, China, in 2010; and to determine the molecular characteristics of the genotype II virus involved.
  
  
  METHODS
  During September and October of 2010, one imported case, a Guangzhou resident who travelled back from Thailand, resulted in 18 secondary autochthonous cases in Guangzhou City, with an incidence rate of 5.53 per 10,000 residents. In indigenous cases, 14 serum samples tested positive for IgM against DENV and 7 for IgG from a total of 15 submitted serum samples, accompanied by 5 DENV-4 isolates. With identical envelope gene nucleotide sequences, the two isolates (D10168-GZ from the imported index case and Guangzhou 10660 from the first isolate in the autochthonous cases) were grouped into DENV-4 genotype II after comparison to 32 previous DENV-4 isolates from GenBank that originated from different areas.
  
  
  CONCLUSIONS
  Based on epidemiological and phylogenetic analyses, the outbreak, which was absent for 20 years after the DENV-4 genotype I outbreak in 1990, was confirmed as DENV-4 genotype II and initially traced to the imported index case, a Guangzhou resident who travelled back from Thailand.
authors.affiliation: Guangzhou Center for Disease Control and Prevention, Guangzhou, People's Republic of China. gdgzcdc@163.com
authors.forename: Qin-Long
authors.initials: QL
authors.lastname: Jing
authors.forename: Zhi-Cong
authors.initials: ZC
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Luo
authors.forename: Xin-Cai
authors.initials: XC
authors.lastname: Xiao
authors.forename: Biao
authors.initials: B
authors.lastname: Di
authors.forename: Peng
authors.initials: P
authors.lastname: He
authors.forename: Chuan-Xi
authors.initials: CX
authors.lastname: Fu
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Jia-Hai
authors.initials: JH
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D016358:Contact Tracing; D003715:Dengue / Q000453:epidemiology* / Q000821:virology*; D003716:Dengue Virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D004196:Disease Outbreaks; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D013785:Thailand; D014195:Travel; D055815:Young Adult
chemical_list: D012367:RNA, Viral