RESUMEN
Objective To estimate the excess numbers of viral diarrheal cases among children aged ＜5 years in Beijing from 1 January 2011 to 23 May 2015.Methods The excess numbers of diarrheal cases among the children aged ＜5 years were estimated by using weekly outpatient visit data from two children' s hospital in Beijing and adjusted Serfling regression model.Results The incidence peaks of viral diarrhea were during 8th-10th week and 40th-42nd week in 2011,40th-4th week in 2012,43rd-49th week in 2013 and 45th week in 2014 to 11th week in 2015 respectively.The excess numbers of viral diarrheal cases among children aged ＜5 years in the two children's hospital were 911(95％CI:261-1 561),1 998(95％CI:1 250-2 746),1 645 (95％CI:891-2 397),2 806(95％CI:1 938-3 674) and 1 822(95％ CI:614-3 031) respectively,accounting for 40.38％ (95％ CI:11.57％-69.19％),44.21％(95％CI:27.66％-60.77％),45.08％(95％CI:24.42％-65.69％),60.87％ (95％CI:42.04％-79.70％) and 66.62％ (95％CI:22.45％-110.82％) of total outpatient visits due to diarrhea during 2011-2015,respectively.Totally,the excess number of viral diarrheal cases among children aged ＜5 years in Beijing was estimated to be 18 731(95％CI:10 106-27 354) from 2011 to 23 May 2015.Conclusions Winter is the season of viral diarrhea for children aged ＜5 years.The adjusted Serfling regression model analysis suggested that close attention should be paid to the etiologic variation of viruses causing acute gastroenteritis,especially the etiologic variation of norovirus.