Abstract: Objective To understand the epidemiological characteristics of diarrheagenic Escherichia coli (DEC) among diarrhea outpatients in sentinel hospitals in Shunyi District of Beijing, and to provide evidences for the prevention and treatment control of diarrhea. Methods C1inical and epidemiological data regarding from diarrhea patients from 2 sentinel surveillance hospitals from 2013 to 2018 were collected,with fecal specimens sampled and tested for DEC. The descriptive epidemiological statistical analysis was performed with SPSS 25.0 and Excel 2010. Results Among all the 2 068 diarrhea cases,182 cases(8.80%)appeared DEC positive,which included the PCR subtypes enterotoxigenic E.coli (ETEC)(111 cases,5.37%), enteropathogenic E.coli (EPEC)(45 cases,2.18%), and enteroaggregative E.coli (EAEC)(27 cases,1.31%).Epidemiological characteristics regarding the heterogeneities of DEC showed no difference in regions,gender and age groups (P>0.05). The positive rate of DEC showed an obvious seasonal distribution,which reached the peaks in summer for all the subtypes,especially, the ETEC(χ²=76.591,P<0.001)and EAEC(χ²=10.204,P<0.05). The positive rates of EPEC (χ²=12.243,P<0.001) and EAEC (χ²=7.947,P<0.01) in local people were higher. The detection rate of EAEC showed significant difference in different ages (χ²=17.171,P<0.05). Fever, nausea, abdominal pain and dehydration had no effect on the detection rate of DEC, but the detection rate of DEC in patients with vomiting, mainly in ETEC (χ²=15.073,P<0.001), was high (χ²=7.099,P<0.01). There was significant difference in the detection rate of EAEC between febrile group and non febrile group(χ²=4.951,P<0.05). Conclusion ETEC, EPEC and EAEC were the predominant bacterial types of DEC in Shunyi. The seasonal characteristics of DEC was obvious,and thus the prevention and control of diarrhea caused by DEC should be strengthened in summer.

Key words: diarrhea, diarrheagenic Escherichia coli, epidemiological characteristics