2020年重庆市179例新型冠状病毒肺炎无症状感染者特征分析

Analysis on characteristics of 179 asymptomatic patients with coronavirus disease 2019 in Chongqing in 2020

目的分析重庆市新型冠状病毒肺炎(COVID-19)无症状感染者的特征,为防控措施提供依据。方法对重庆市2020年1月21日至7月31日报告的无症状感染者特征进行描述性流行病学分析。结果全市共报告无症状感染者179例,占COVID-19感染者比例的23.49%;男女比例1.00∶1.08,以农民最多、高发年龄为20~30岁;分布于24个区县,以万州区报告最多(66例)。感染来源以输入引起的本地感染为主(91例,50.84%);主要发现途径为经病例密切接触者筛查和聚集疫情调查发现(112例,62.57%)。由无症状感染者引起的聚集疫情8起,占全市COVID-19疫情的9.09%(8/88)。从诊断到解除隔离的时间,<15 d的占53.37%,15~28 d的占34.27%,>28 d的占12.36%。结论加强密切接触者、重点地区或重点人群新型冠状病毒(SARS-Cov-2)检测,对疫情防控有着积极作用;无症状感染者解除医学观察后,需开展2~4周的健康监测。

Objective To analyze characteristics of asymptomatic patients with coronavirus disease 2019(COVID-19)in Chongqing and provide basis for the prevention and control.Methods Descriptive epidemiological analysis was carried out on the characteristics of asymptomatic infection cases with COVID-19 reported from January 21 to July 31,2020 in Chongqing.Results A total of 179 asymptomatic infection cases with COVID-19 were reported in Chongqing,accounting for 23.49%of COVID-19 infection.The male-to-female ratio was 1.00:1.08,with the highest proportion of farmers and the highest incidence age group 20-30 years old;cases were found in 24 districts and counties,and Wanzhou district reported the most(66 cases).The main source of infection was local infection(91 cases,50.84%).112 cases(62.57%)were found by close contact screening and cluster epidemic investigation.There were 8 clustering outbreaks caused by asymptomatic patients(9.09%,8/88).The time from diagnosis to isolation was 53.37%within 15 days,34.27%within 15-28 days,and 12.36%over 28 days.Conclusion Strengthen close contacts,key areas or key population of severe acute respiratory syndrome coronavirus 2(SARS-Cov-2)testing has a positive effect on the prevention and control of the epidemic;after the asymptomatic patients is released from medical observation,health monitoring for 2 to 4 weeks is required.