一起可能由境外邮件引起的新冠肺炎聚集性疫情调查

Investigation of a COVID-19 aggregated epidemic possibly caused by overseas mail

目的 分析北京市海淀区一起可能由境外邮件引起的新冠病毒Omicron变异株聚集性疫情的流行特征和传播链,了解Omicron变异株可能的传播路径和传播特点。方法 采用现场流行病学调查方法核查该传播链上所有病例的活动轨迹,逐一排查涉及的风险点,同时对新冠病毒核酸阳性样本进行基因测序用于溯源分析。结果 此次聚集性疫情共涉及6例新冠肺炎确诊病例,病例感染的病毒基因序列和其接触的境外邮件以及同一来源发往另一地点尚未拆封的阳性邮件基因序列高度同源,与同期北美、新加坡等地流行的新冠病毒相似度较高,与同期我国其他地区疫情无关联。结论 携带新冠病毒的邮件物品存在传播的可能性,引起聚集性疫情。应加强快递邮件的消毒方法研究并实施,多渠道阻断传播风险。

Objective To analyze the epidemic characteristics and transmission chain of a COVID-19 aggregated epidemic of SARS-CoV-2 Omicron variant caused by overseas mail in Haidian district,Beijing,and to understand the possible transmission path and characteristics of Omicron variant. Methods The active tracks of all cases on the transmission chain were verified by field epidemiological investigation,and the risk points involved were investigated one by one. Meanwhile,gene sequencing of nucleic acid positive samples of SARS-CoV-2 was carried out for origin-tracing analysis. Results The aggregated epidemic involved 6 confirmed cases of COVID-19. The virus gene sequence of the case infection was highly homologous with the foreign mail,and the positive samples of the same source sent to another location,which had not been unsealed. It had a high similarity with the virus strains prevalent in the same period in North America and Singapore,and was not related to the epidemic in the same period in other areas of China. Conclusion There is a possibility of transmission by mail articles carrying SARS-CoV-2,causing cluster epidemic. Research and implementation of disinfection methods for express mail should be strengthened to block transmission risks through multiple channels.