title: Acute gastroenteritis outbreak caused by a GII.6 norovirus.
abstract: OBJECTIVE
  To report an acute gastroenteritis outbreak caused by a genogroup 2 genotype 6 (GII.6) strain norovirus in Shanghai, China.
  
  
  METHODS
  Noroviruses are responsible for approximately half of all reported gastroenteritis outbreaks in many countries. Genogroup 2 genotype 4 strains are the most prevalent. Rare outbreaks caused by GII.6 strains have been reported. An acute gastroenteritis outbreak occurred in an elementary school in Shanghai in December of 2013. Field and molecular epidemiologic investigations were conducted.
  
  
  RESULTS
  The outbreak was limited to one class in an elementary school located in southwest Shanghai. The age of the students ranged from 9 to 10 years. The first case emerged on December 10, 2013, and the last case emerged on December 14, 2013. The cases peaked on December 11, 2013, with 21 new cases. Of 45 students in the class, 32 were affected. The main symptom was gastroenteritis, and 15.6% (5/32) of the cases exhibited a fever. A field epidemiologic investigation showed the pathogen may have been transmitted to the elementary school from employees in a delicatessen via the first case student, who had eaten food from the delicatessen one day before the gastroenteritis episodes began. A molecular epidemiologic investigation identified the cause of the gastroenteritis as norovirus strain GII.6; the viral sequence of the student cases showed 100% homology with that of the shop employees. Genetic relatedness analyses showed that the new viral strain is closely related to previously reported GII.6 sequences, especially to a strain reported in Japan.
  
  
  CONCLUSIONS
  This is the first report to show that norovirus strain GII.6 can cause a gastroenteritis outbreak. Thus, the prevalence of GII.6 noroviruses requires attention.
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Ling-Fei
authors.initials: LF
authors.lastname: Luo
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Qiao
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Wang
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Ke-Ying
authors.initials: KY
authors.lastname: Ding
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Hua-Ling
authors.initials: HL
authors.lastname: Su
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Cui-Zhen
authors.initials: CZ
authors.lastname: Li
authors.affiliation: Ling-Fei Luo, Kun Qiao, Xiao-Guang Wang, Ke-Ying Ding, Hua-Ling Su, Cui-Zhen Li, Hong-Jing Yan, The Center for Disease Control and Prevention of Minghang District, Minghang District, Shanghai 201101, China.
authors.forename: Hong-Jing
authors.initials: HJ
authors.lastname: Yan
mesh_terms: D000208:Acute Disease; D017250:Caliciviridae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D002648:Child; D002681:China / Q000453:epidemiology; D016358:Contact Tracing; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D012189:Retrospective Studies; D012574:Schools
chemical_list: D012367:RNA, Viral
keywords: Gastroenteritis; Genetic relatedness analyses; Genogroup 2 genotype 6 genogroup; Noroviruses; Outbreak