北京市新型冠状病毒肺炎无症状感染者的特征分析

Characteristics of asymptomatic COVID-19 patients in Beijing

目的:了解北京市新型冠状病毒肺炎无症状感染者的流行病学特征。方法:描述分析2020年2月1日至11月30日北京市新冠肺炎无症状感染者流行病学特征。结果:北京市54例新冠肺炎无症状感染者平均年龄(37.19±15.99)岁,男女比例为1.45:1;以接触确诊病例(45.28%)或其污染的环境(43.40%)而感染为主;42.59%(23例)通过密切接触者筛查发现;从末次暴露到首次核酸检出阳性时间间隔中位数为11 d;仅2例无症状感染者的2名密切接触者(2/1139,0.18%)不排除为续发病例。结论:新冠肺炎无症状感染者以中青年为主,主要通过接触确诊病例或其污染的环境感染,密切接触者筛查是发现无症状感染者的主要途径,不排除无症状感染者造成传播的可能,应加强对无症状感染者的发现力度,继续严格管理。

Objective To understand epidemiological characteristics of asymptomatic patients of coronavirus disease 2019(COVID-19)in Beijing.Methods The epidemiological characteristics of asymptomatic COVID-19 patients in Beijing from February 1,2020 to November 30,2020 were analyzed by descriptive method.Results The average age of 54 asymptomatic COVID-19 patients was(37.19±15.99)years old.The male to female ratio was 1.45:1.The infections were mainly caused by contacting with confirmed cases(45.28%)and contacting with environment contaminated by confirmed cases(43.40%).Tweenty-three cases(42.59%)were identified by screening of close contacts.The median time interval from the last exposure to the first positive nucleic acid detection was 11 days.Only two close contacts(2/1139,0.18%)of the two asymptomatic patients were not excluded as the secondary cases.Conclusions The majority of asymptomatic COVID-19 patients were young and middle-aged adults,who were infected mainly through contact with confirmed cases or patient-contaminated environment.Screening in the close contacts was the main route to identify asymptomatic patients.The transmission caused by asymptomatic patients can’t be ruled out.The detection of asymptomatic patients should be strengthened with continuous strict management.