西安市新型冠状病毒肺炎无症状感染者特征分析  

Characteristics of asymptomatic COVID-19 patients in Xi'an city

作　　者：张辉[1] 白妙 李倩[1] 李思瑶 冀贞浩[1] 王鹏飞 ZHANG Hui;BAI Miao;LI Qian;LI Si-yao;JI Zhen-hao;WANG Peng-fei(Department of Infectious Disease Control,Xi’an Center for Disease Control and Prevention,Xi’an,Shaanxi 710054,China)

机构地区：[1]西安市疾病预防控制中心传染病预防控制科,陕西西安710054 [2]陕西省传染病医院 [3]西安市高陵区疾病预防控制中心,陕西西安710201

出　　处：《现代预防医学》2021年第2期350-353,358,共5页Modern Preventive Medicine

基　　金：西安市卫生科研项目(J201802036)。

摘　　要：目的分析西安市新型冠状病毒肺炎(COVID-19)无症状感染者的特征,为更好地防控疫情提供参考依据。方法收集疫情应急处置期间无症状感染者的现场流行病学调查资料,采用描述性流行病学方法进行分析。结果截至2020年5月10日,西安市共报告无症状感染者25例(男12例,女13例),中位年龄46.0(18.5,65.0)岁,占全市17.24%(25/145)。其中15例(60.00%)为确诊病例密切接触者,8例(32.00%)有湖北旅居史,2例(8.00%)为无症状感染者的密切接触者;23例(92.00%)经聚集性疫情传染源溯源和确诊病例/无症状感染者密切接触者排查发现,1例(4.00%)为协查外市确诊病例密切接触者发现,1例(4.00%)为筛查高危地区来陕人群发现。25例无症状感染者末次暴露到首次核酸检测阳性中位时间为17.0 d,集中医学观察开始至首次核酸检测阳性中位时间为8.0 d,首次核酸检测阳性至转阴出院中位时间为14.0 d。CT显示78.57%(11/14)无症状感染者肺部存在不同程度的小结节影、斑片状影、磨玻璃样影和边界欠清晰状况。结论无症状感染者主要经聚集性疫情调查和确诊病例/无症状感染者密切接触者排查发现。及时全面排查密切接触者并对其进行集中医学观察,能减少其可能造成的疫情持续传播。肺部影像学特征性改变可作为早期排查的重要参考。Objective To analyze the epidemiological characteristics of asymptomatic COVID-19 patients in Xi’an city, so as to provide references for the prevention and control of COVID-19. Methods Descriptive epidemiological analysis was conducted on the data of asymptomatic COVID-19 patients obtained from field epidemiological reports. Results Totally 25 local asymptomatic patients(12 males and 13 females) were reported as of May 10, with the median age of 46(18.5 years, 65.0 years) and accounting for 17.24%(25/145) of total cases. Among them, 15 cases(60.00%) were close contacts of confirmed cases, eight cases(32.00%) had travel history to Hubei, two cases(8.00%) were close contacts of asymptomatic infected persons, 23 cases(92.00%) were identified by aggregated epidemic infectious source tracing and screening of close contacts of confirmed cases/asymptomatic infected persons, and one case(4.00%) was found by screening close contacts of confirmed cases in a collaborative investigation outside the city. The median duration from last exposure to first positive nucleic acid test for 25 asymptomatic infected patients was 17.0 days. The median duration from the beginning of intensive medical observation to first positive nucleic acid test was 8.0 days. The median duration from first positive nucleic acid test to discharge from hospital was 14.0 days. CT showed that 78.57%(11/14) of asymptomatic infected patients had varying degrees of abnormal lung conditions such as small nodular, patchy, ground glass shadows and poorly defined border. Conclusion Asymptomatic infected patients were mainly identified by aggregated outbreak investigation and close contact screening of confirmed cases/asymptomatic infected patients. Timely and comprehensive screening of close contacts and intensive medical observation of them can reduce the possibility of continued transmission. Characteristic pulmonary imaging changes can be used as an important reference for early screening.

关 键 词：新型冠状病毒肺炎 无症状感染者 密切接触 医学观察 流行特征 

分 类 号：R183[医药卫生—流行病学]