新型冠状病毒肺炎聚集性疫情中无症状感染者与确诊患者的流行差异

 目的 探讨无症状新型冠状病毒感染者(无症状感染者)流行特征。方法 通过中国疾病预防控制系统,收集、汇总河南省含有无症状感染者的聚集性疫情,描述其流行特征,分析与新型冠状病毒肺炎确诊病例流行特征的差异。结果 共报告聚集性疫情257起,其中41起有无症状感染者,包含84例无症状感染者,占全省无症状感染者的74.34％(84/113)。无症状感染者聚集性疫情分布在11个地市,涉及新型冠状病毒感染者208例,平均每起波及新型冠状病毒感染者5.07(2~19)例,16起(39.02%)新型冠状病毒感染者≥5例。无症状感染者的发现以聚集性疫情调查为主,确诊时间晚于新型冠状病毒肺炎确诊病例。河南省各地市无症状感染者占新型冠状病毒感染者的比率,以商丘市最高,为26.02%。无症状感染者与新型冠状病毒肺炎确诊病例比较,性别分布流行病学史方面,差异均无统计学意义(均P>0.05);年龄及职业的分布构成比较,差异均有统计学意义(均P<0.05),无症状感染者≤40岁者占58.33%,学生、儿童占28.57%,确认者分别占21.77%、4.03%。结论 无症状感染者在年龄和职业分布上与新型冠状病毒肺炎确诊病例存在差异。聚集性疫情调查是发现无症状感染者的主要途径,对密切接触者进行有效的隔离管理是正确有效的防控措施。

Difference in epidemic characteristics between asymptomatic infected persons and confirmed cases in COVID-19 clustered epidemics

Objective To explore epidemic characteristics of asymptomatic coronavirus disease 2019 (COVID-19) -infected persons. Methods Clustered epidemics involving asymptomatic infected persons in Henan Province were collected and summarized through Chinese Disease Control and Prevention System, epidemic characteristics were analyzed, differences in epidemic characteristics between asymptomatic infected persons and confirmed cases of COVID-19 were analyzed. Results A total of 257 clustered epidemics were reported, 41 of which involved 84 asymptomatic infected persons, accounting for 74.34%(84/113) of asymptomatic infection in the whole province. The clustered epidemics of asymptomatic infected persons distributed in 11 prefectures, involving 208 cases of COVID-19, each epidemic involved an average of 5.07 (2-19) COVID-19 infection cases, 16 (39.02%) had at least 5 COVID-19 infection cases. The discovery of asymptomatic infection was mainly based on clustered epidemic investigation, diagnosis time was later than that of COVID-19 confirmed cases. The proportion of asymptomatic infection among COVID-19 infection in various cities in Henan Province was the highest in Shangqiu City(26.02%). Asymptomatic infected persons and COVID-19 confirmed cases were statistically different in gender distribution and epidemiological history (both P>0.05); differences in constituent ratios of age and occupational distribution were both statistically significant (both P<0.05), asymptomatic infected persons ≤ 40 years old accounted for 58.33%, students and children accounted for 28.57%, and confirmed cases accounted for 21.77% and 4.03% respectively. Conclusion The age and occupational distribution of asymptomatic infected persons are different from those diagnosed with COVID-19. Investigation on clustered epidemic is the main way to find asymptomatic infected persons, effective isolation management of close contacts is the correct and effective prevention and control measure.