Sun Y M, Liu Feng, Cai Wei, Wang Lei, Liu Fangyao, Li Yulian, Wang Juguang, Ying Huaqing, Fu Jiye
Haidian District Center for Disease Control and Prevention, Beijing 100094, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2021 Mar 10;42(3):427-432. doi: 10.3760/cma.j.cn112338-20201027-01285.
To investigate the clusters of COVID-19 associated with a market (market Y) in Haidian District, Beijing, and analyze the chain of transmission and provide reference for effective prevention and control of COVID-19. The investigation of field epidemiology and cluster epidemic was used to describe the distributions of all COVID-19 cases. The time sequence diagram of the cases, disease onset was drawn and transmission chains were analyzed. Real-time RT-PCR assay was conducted for SARS-CoV-2 nucleic acid test by using the respiratory samples of the cases. The COVID-19 epidemic, originated from a wholesale farm produce market (market X) in Fengtai District, Beijing, was introduced by a marketer in the market Y who had exposed to market X, causing 8 clusters of 20 confirmed cases of COVID-19 and one asymptomatic case, including 8 men and 13 women, in market Y, surrounding communities, food plaza, companies,families and other places. The incidence peaked during June 10-14, 2020; the median age of the cases was 45 years, ranging from 5 years to 87 years. The initial symptoms of the cases included fever (10/20) and pharynx discomfort (7/20). The median of incubation period was 5 days (:3-8). The median of serial interval between primary case and secondary cases was 5 days with a secondary attack rate of 3.7%(20/538), and the secondary attack rate in household close-contacts was 14.0% (7/50). The clusters of COVID-19 associated with market Y were caused by several modes of transmission, including human-to-human, contaminated material-to-human, . The combined public-health response measures were effective to control the COVID-19 epidemic in Haidian district of Beijing.
为调查北京市海淀区某市场（Y市场）相关的新型冠状病毒肺炎聚集性疫情，分析传播链条，为新型冠状病毒肺炎的有效防控提供参考。采用现场流行病学调查和聚集性疫情调查方法描述所有新型冠状病毒肺炎病例的分布情况。绘制病例发病时间序列图，分析传播链条。采集病例呼吸道样本，采用实时荧光定量RT-PCR法进行新型冠状病毒核酸检测。北京市丰台区某农产品批发市场（X市场）的新型冠状病毒肺炎疫情，由Y市场一名接触过X市场的销售人员传入，在Y市场、周边社区、美食广场、公司、家庭等场所引发8起聚集性疫情，共20例确诊病例和1例无症状感染者，其中男性8例，女性13例。发病高峰在2020年6月10日至14日；病例中位年龄45岁，年龄范围5岁至87岁。病例初始症状包括发热（10/20）和咽部不适（7/20）。潜伏期中位数为5天（范围：3至8天）。首例病例与续发病例的间隔时间中位数为5天，二代发病率为3.7%（20/538），家庭密切接触者二代发病率为14.0%（7/50）。与Y市场相关的新型冠状病毒肺炎聚集性疫情由多种传播方式引起，包括人传人、污染物品传人等。综合公共卫生应对措施有效控制了北京市海淀区的新型冠状病毒肺炎疫情。
