3CHAPMAN AS,WITKOP CT,ESCOBAR JD,et al.Norovirus outbreak associated with person-to-person transmission,U.S.Air Force Academy,July 2011[J].MSMR,2011,18(11):2.
4PATEL MM, WIDDOWSON MA, GLASS RI, et al. Systematic literature review of role of noroviruses in sporadic gastroenteritis [J]. Emerg Infect Dis,2008,14(8):1224.
5WIKSWO ME, HALL AJ, Centers for Disease Control and Pre vention. Outbreaks of acute gastroenteritis transmitted by person- to-person contact-United States, 2009- 2010[J]. MMWR Sur- veill Summ, 2012,61 (9) : 1.