title: [Analysis of epidemiology characteristics of norovirus among diarrheal outpatients in 27 provinces in China, 2009-2013].
abstract: OBJECTIVE
  To investigate the epidemiology characteristics of norovirus among diarrheal outpatients in China.
  
  
  METHODS
  Diarrhea cases were monitored at emergency/outpatient departments at 173 hospitals in 27 provinces of China, with clinical and epidemiological data, and fecal specimens collected and sent to 58 network-laboratories to detect norovirus by RT-PCR method, and to analyze the positive rate of norovirus in various regions, population and time during 2009-2013.
  
  
  RESULTS
  11.6% of the 34 031 diarrheal cases under surveillance were found with norovirus. Age group of 6-23 month-old children and that of people over 45 years old were found with the highest positive percentage, 13.7% and 12.4% respectively. Positive percentage of norovirus peaks in autumn and winter in a year; it peaks in mid-temperate zones (10.7%) and warm-temperate zones (11.6%) in winter. It peaks in sub-tropical zones in autumn (14.3%). The most prevalent genogroups detected were norovirus G II, accounting for 89.9% of identified strains.
  
  
  CONCLUSIONS
  Norovirus affects all ages and was most prevalent in children and the elderly among diarrhea outpatients. Norovirus' positive percentage showed strong seasonal pattern, and peaks at different times of a year in different climate zones of China. Since no effective preventive measures existed, further study on norovirus epidemiology and intervention strategies should be conducted in future.
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Jianxing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Lai
authors.affiliation: National Institute for Communicable Diseases Control and Prevention, Beijing 102206, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Qiaohong
authors.initials: Q
authors.lastname: Liao
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Luzhao
authors.initials: L
authors.lastname: Feng
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Ran
authors.affiliation: National Institute for Viral Diseases Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University.
authors.forename: Yanzi
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University.
authors.forename: Zike
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University.
authors.forename: Mengfeng
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Military Medical Science Academy.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Shanghai Public Health Clinical Center.
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Yunnan Provincial Center for Disease Control and Prevention.
authors.forename: Shiwen
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Gansu Provincial Center for Disease Control and Prevention.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Wang
authors.affiliation: Liaoning Provincial Center for Disease Control and Prevention.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Yu
authors.affiliation: National Institute for Communicable Diseases Control and Prevention, Beijing 102206, China.
authors.forename: Huaiqi
authors.initials: H
authors.lastname: Jing
authors.affiliation: Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Beijing 102206, China.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Li
authors.affiliation: Chinese Center for Disease Control and Prevention; Email: yangwz@chinacdc.cn.
authors.forename: Weizhong
authors.initials: W
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017250:Caliciviridae Infections / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003967:Diarrhea / Q000453:epidemiology / Q000821:virology*; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007753:Laboratories; D008875:Middle Aged; D029322:Norovirus; D010045:Outpatients; D015995:Prevalence; D012621:Seasons