title: Evidence-Based interventions of Norovirus outbreaks in China.
abstract: In resource-limited settings where laboratory capacity is limited and response strategy is non-specific, delayed or inappropriate intervention against outbreaks of Norovirus (NoV) are common. Here we report interventions of two norovirus outbreaks, which highlight the importance of evidence-based modeling and assessment to identify infection sources and formulate effective response strategies.
  
  
  
  Spatiotemporal scanning, mathematical and random walk modeling predicted the modes of transmission in the two incidents, which were supported by laboratory results and intervention outcomes.
  
  
  
  Simulation results indicated that contaminated water was 14 to 500 fold more infectious than infected individuals. Asymptomatic individuals were not effective transmitters. School closure for up to a week still could not contain the outbreak unless the duration was extended to 10 or more days. The total attack rates (TARs) for waterborne NoV outbreaks reported in China (n = 3, median = 4.37) were significantly (p < 0.05) lower than worldwide (n = 14, median = 41.34). The low TARs are likely due to the high number of the affected population.
  
  
  
  We found that school closure alone could not contain Norovirus outbreaks. Overlooked personal hygiene may serve as a hotbed for infectious disease transmission. Our results reveal that evidence-based investigations can facilitate timely interventions of Norovirus transmission.
authors.affiliation: Office for Disease Control and Emergency Response, Changsha Center for Disease Control and Prevention, 149 Wei'er Road, Changsha, Hunan, People's Republic of China.
authors.forename: Tianmu
authors.identifier: 0000-0002-7541-4262
authors.initials: T
authors.lastname: Chen
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors.forename: Haogao
authors.initials: H
authors.lastname: Gu
authors.affiliation: Office for Disease Control and Emergency Response, Changsha Center for Disease Control and Prevention, 149 Wei'er Road, Changsha, Hunan, People's Republic of China. ross@cuhk.edu.hk.|School of Public Health, The University of Hong Kong, Hong Kong SAR, People's Republic of China. ross@cuhk.edu.hk.|Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China. ross@cuhk.edu.hk.
authors.forename: Ross Ka-Kit
authors.initials: RK
authors.lastname: Leung
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors.forename: Ruchun
authors.initials: R
authors.lastname: Liu
authors.affiliation: Hospital, Shanghai Normal University, Shanghai, People's Republic of China.|Office for Disease Control and Emergency Response, Tianxin Center for Disease Control and Prevention, Changsha, Hunan, People's Republic of China.
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Office for Disease Control and Emergency Response, Tianxin Center for Disease Control and Prevention, Changsha, Hunan, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors.forename: Yaman
authors.initials: Y
authors.lastname: Li
mesh_terms: D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D002681:China / Q000453:epidemiology; D003140:Communicable Disease Control / Q000379:methods*; D004196:Disease Outbreaks; D060766:Drinking Water / Q000009:adverse effects / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D029322:Norovirus; D012574:Schools; D062211:Spatio-Temporal Analysis
chemical_list: D060766:Drinking Water
keywords: Mathematical model; Norovirus; Outbreak; Water disinfection