陕西本土新型冠状病毒肺炎无症状感染者流行特征及传播途径

Epidemiological characteristics and transmission routes of COVID-19 asymptomatic infected patients in Shaanxi Province

目的评估陕西省本土新冠肺炎无症状感染者的流行特征及传播风险。方法收集陕西省截至2020年3月26日新冠肺炎本土病例的密接人群数据库,通过病例流行病学调查报告筛选出28例无症状感染者,进行描述性分析。结果陕西省本土新冠肺炎无症状感染者以20~59岁中青年为主,女性多于男性,82.14%无症状感染者在集中隔离状态下被发现,近80%的无症状感染者与确诊病例是以共同家庭生活为主要接触方式。所有无症状感染者从与传染源末次接触到检测阳性的中位天数为13 d,其中有3例(10.71%)出现了临床症状。流行病学调查发现无症状感染者可由共同家庭生活造成传播。结论目前陕西省境外输入病例持续存在,考虑到无症状感染传播的隐匿性,疫情防控工作仍然面临挑战。

Objective To assess the epidemiological characteristics and transmission risk of asymptomatic COVID-19 infection in Shaanxi Province. Methods A dense population database of COVID-19 cases in Shaanxi Province was constructed as of March 26, 2020, and 28 asymptomatic infected patients were selected through case epidemiological investigation report for descriptive analysis. Results In Shaanxi Province, the majority of asymptomatic COVID-19 infections were in the 20-59 years old group, and women took up a higher proportion than men. 82.14% of asymptomatic infections were found in the centralized isolation state. Nearly 80% of asymptomatic infections and confirmed cases were mainly exposed by living together in the family. The median number of days from last contact with the source of infection for all asymptomatic infected persons was 13, with 3(10.71%) showing clinical symptoms. Epidemiological investigations showed that asymptomatic infections could spread as a result of shared family life. Conclusion At present, imported cases in Shaanxi Province continue to exist. Considering the concealed transmission of asymptomatic infections, prevention and control work is still facing challenges.