Fudan University School of Public Health, Shanghai, China.
Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China.
Epidemiol Infect. 2023 Nov 13;152:e9. doi: 10.1017/S0950268823001796.
A local COVID-19 outbreak with two community clusters occurred in a large industrial city, Shaoxing, China, in December 2021 after serial interventions were imposed. We aimed to understand the reason by analysing the characteristics of the outbreak and evaluating the effects of phase-adjusted interventions. Publicly available data from 7 December 2021 to 25 January 2022 were collected to analyse the epidemiological characteristics of this outbreak. The incubation period was estimated using Hamiltonian Monte Carlo method. A well-fitted extended susceptible-exposed-infectious-recovered model was used to simulate the impact of different interventions under various combination of scenarios. There were 387 SARS-CoV-2-infected cases identified, and 8.3% of them were initially diagnosed as asymptomatic cases. The estimated incubation period was 5.4 (95% CI 5.2-5.7) days for all patients. Strengthened measures of comprehensive quarantine based on tracing led to less infections and a shorter duration of epidemic. With a same period of incubation, comprehensive quarantine was more effective in containing the transmission than other interventions. Our findings reveal an important role of tracing and comprehensive quarantine in blocking community spread when a cluster occurred. Regions with tense resources can adopt home quarantine as a relatively affordable and low-impact intervention measure compared with centralized quarantine.
2021 年 12 月，中国绍兴市发生了一起局部新冠肺炎疫情，涉及两个社区集群。在实施了一系列干预措施后，疫情得到了控制。本研究旨在通过分析疫情特征和评估阶段性调整干预措施的效果，了解疫情发生的原因。本研究收集了 2021 年 12 月 7 日至 2022 年 1 月 25 日的公开数据，分析了该起疫情的流行病学特征。采用 Hamilton 蒙特卡罗方法估计潜伏期。采用拟合良好的扩展易感性-暴露-感染-恢复模型，模拟了不同干预措施在不同场景组合下的效果。共发现 387 例 SARS-CoV-2 感染病例，其中 8.3%最初被诊断为无症状病例。所有患者的估计潜伏期为 5.4（95%CI 5.2-5.7）天。基于追踪的强化综合隔离措施减少了感染人数，缩短了疫情持续时间。在相同潜伏期内，综合隔离比其他干预措施更能有效阻断传播。研究结果表明，在集群发生时，追踪和综合隔离在阻断社区传播方面发挥了重要作用。资源紧张的地区可以采用居家隔离作为一种相对经济实惠、影响较小的干预措施，而不是集中隔离。
