一起通过血清抗体检测溯源的新型冠状病毒肺炎聚集性疫情调查

Investigation of COVID-19 Cluster Outbreaks Traced by Serum Antibody Tests

目的:分析南通市一起新型冠状病毒肺炎聚集性疫情,为制定合理的防控策略提供科学依据。方法:根据现场流行病学调查方法,以首发病例为线索,对病人和密切接触者进行个案调查,分析感染来源、传播链和病例代系,利用血清抗体结果进行回顾性分析。结果:本起聚集性疫情涉及4代共11名病例,5例确诊病例,3例无症状感染者,3例既往感染者。男性3人,女性8人,平均年龄55岁。3例确诊病例有发热、咳嗽等临床症状,2例确诊病例仅有肺部影像学表现。病例的暴露场所共4种,其中家庭暴露5人,聚餐暴露3人,集体单位暴露2人,公共场所暴露(医院)1人。首发病例通过家庭日常接触、聚餐和集体单位接触传给2代病例,2代病例通过家庭内传播和亲友聚餐传给3代病例,3代病例通过医院内感染传播给4代病例。2例确诊病例有明确的单次暴露时间,潜伏期分别为4天和6天。结论:利用通信数据、抗体检测等手段,追溯传染源,分析疫情传播方式,对病例及其密切接触者及时隔离管控,可以有效控制疫情进一步扩散。

OBJECTIVE To analyze a COVID-19 cluster in Nantong and provide scientific basis for formulating reasonable prevention and control strategies. METHODS According to the epidemiological investigation method, based on the first case as a clue,patients and close contacts were investigated, the source of infection, transmission chain and case lineage were analyzed and retrospective investigation was conducted based on serum antibody test. RESULTS A total of 11 cases, 5 confirmed cases, 3 asymptomatic infected persons and 3 previously infected persons were involved in the cluster outbreak. There were 3 males and 8 females with an average age of 55, and 3 confirmed cases had clinical symptoms such as fever and cough. There were 4 exposure places for cases, including 5 cases exposed in a family, 3 cases exposed in a dinner party, 2 cases exposed in a collective unit, and 1 case exposed in a public place( hospital). First-generation cases were transmitted to second-generation cases through daily family contact, dinner-party contact and collective unit contact;second-generation cases were transmitted to third-generation cases through intra-family transmission and dinner-party contact;third-generation cases were transmitted to fourth-generation cases through nosocomial infection.Two confirmed cases had a clear time of single exposure with incubation periods of 4 days and 6 days, respectively. CONCLUSION The further spread of the epidemic could be effectively controlled by using communication data and antibody detection to trace the source of infection, analyze the transmission mode of the epidemic, and timely isolate and control the cases and their close contacts.