Epidemiological characteristics of associated epidemics in Tongzhou district, Beijing, 2015-2020

  Objective  To analyze the characteristics of the associated epidemics in Tongzhou district of Beijing from 2015 to 2020, identify the risk factors and provide scientific basis for the early warning, prevention and control of infectious disease epidemics.

  Methods  The surveillance data and investigation reports of associated epidemics in Beijing from January 1, 2015 to December 31, 2020 were collected from Beijing Infectious Disease Surveillance and Epidemiological Investigation System for a descriptive analysis on the epidemiological and etiological characteristics of associated epidemics in Tongzhou. The data were processed with Excel 2013.

  Results  From 2015 to 2020, a total of 237 cases in associated epidemics were reported in Tongzhou, including 96 cases of fever, 102 cases of diarrhea, 37 cases of rash, 2 cases of conjunctival redness and 0 cases of jaundice. Among the 37 cases of rash, 27 hand-foot-mouth disease or herpetic angina cases were diagnosed, and 5 varicella cases were diagnosed. The incidence peak of the 237 cases was during June–August, and the secondary peak was in November. The incidence peak of the 102 cases of diarrhea was during June–September. The incidence peaks of fever were in June, December and January. The incidence peaks of rash were during May–June and during October–November, and two conjunctiva redness cases occurred in November and December. The top 5 townships with high case numbers were Liyuan (53 cases), Yongshun (29 cases), Songzhuang (19 cases), Lucheng (18 cases) and Zhangjiawan (16 cases). The associated epidemics mainly occurred in urban area and rural-urban continuum. The associated epidemics occurred in middle and primary schools (child care settings) in Tongzhou accounted for the highest proportion of the total, followed by that in family, company or collective dormitories, restaurants or the tourist groups to Beijing, vocational college or professional training institution, construction site. In 2020, the proportion of associated epidemics in primary school (child care settings) dropped sharply, and the proportions in other settings considerably increased. The pathogens of 18 associated epidemics were identified in 2020.

  Conclusion  The types of associated epidemics in Tongzhou varied with month, showing high consistency with other surveillance data. It is necessary to strengthen epidemic prevention and control in key areas, such as urban area and urban-rural continuum, vocational college or professional training institution, family, construction site and other specific places, and conduct pathogen detection through the Infectious Disease Surveillance and Epidemiological Investigation System of Beijing.