天津市第137例新型冠状病毒肺炎病例在京感染风险分析

Risk factors of possible source of infection of the 137th Confirmed Case of coronavirus disease 2019 in Tianjin:An investigation in Beijing

目的了解天津市第137例新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)确诊病例的疑似传染源(IgM抗体检出阳性,以下简称S)在京感染风险。方法2020年6月23-24日,对S进行流行病学调查,收集其5月30日后在京活动史及其密切接触者,采集并检测S在京密切接触者的咽拭子和血样本,以及在京活动场所的外环境样本。结果自5月30日,S三次来京看望其女友(下文简称G),主要活动场所为G住址,还涉及餐馆A、酒馆B、酒吧C等3处公共场所;共有密切接触者65人,其中G住址涉及女友1人、餐馆A涉及34人、酒馆B涉及21人、酒吧C涉及9人。采集全部65名密切接触者咽拭子样本和血样本进行新型冠状病毒核酸和抗体检测,结果均为阴性;采集4个活动场所96件外环境样本进行核酸检测,结果均为阴性。结论基于S在京调查的证据,不支持S在京公共场所感染,S的血清IgM抗体阳性原因需进一步排查。

Objective To know the risk factors of a person(S for short)who was tested positive for IgM and was the possible source of infection of the 137th Confirmed Case of COVID-19 in Tianjin.Methods From June 23,2020 to June 24,2020,we conducted the epidemiological investigation to collect his information of exposure history and close contacts in Beijing since May 30,and collected and tested throat swabs and blood samples of close contacts,as well as the environmental samples of the places he had visited in Beijing.Results S had visited his girlfriend(G for short)in Beijing three times since May 30.During his time in Beijing,he usually stayed in G’s address,and visited three public places such as Restaurant A,Pub B and Bar C.There were 65 close contacts,including his girlfriend from G’s address,34 from Restaurant A,21 from Pub B and 9 from Bar C.Throat swabs and blood samples of 65 close contacts were collected for nucleic acid and antibody detection,as well as 96 environmental samples were collected for nucleic acid detection,and all the samples were tested negative.Conclusions The result would not rule the false positive IgM antibody tests out,and indicated that the risk of COVID-19 infection for S was low in public places in Beijing.