Estimation of excess number of diarrhea cases in intestinal disease outpatients in Beijing with adjusted Serfling regression model, 2012−2019

  Objective  To estimate the excess number of diarrhea cases in intestinal disease outpatients in Beijing and analyze the characteristics of the excess cases.

  Methods  The number of diarrhea cases diagnosed for the first time in 16 intestinal outpatient departments providing service all the year around in Beijing from 2012 to 2019 were collected to estimate the excess number of diarrhea cases with adjusted Serfling regression model.

  Results  From 2012 to 2019, a total of 216 930 diarrhea cases were diagnosed for the first time in the 16 intestinal outpatient departments in Beijing, the age of the cases was mainly above 18 years. With adjusted Serfling regression model, 10 excess diarrhea epidemic periods were found, in which 28 135 excess cases occurred (95% CI: 13 423–42 847), accounting for 50.10% of the baseline level (95% CI: 23.90%–76.29%). The excess number of diarrhea cases diagnosed in the intestinal outpatient departments in spring, summer, autumn and winter were 2 673 (95% CI: 985–4 361), 11 564 (95% CI: 6 296–16 833), 2 570 (95% CI: 1 112–4 028) and 11 328 (95% CI: 5 030–17 626), respectively. The excess number of diarrhea cases in summer showed a decrease trend from 2012 to 2019 in Beijing ( χ²=5949.180, P<0.001), while the excess number of diarrhea cases in winter has been in increase since 2016.

  Conclusion  Summer is the peak season of diarrhea diagnosis in Beijing, but in recent years, excess number of diarrhea cases increased obviously in winter. It is necessary to strengthen the surveillance for viral diarrhea in winter and adjust the corresponding prevention and control strategies.