Epidemiological investigation and intergenerational clinical characteristics of 24 COVID-19 patients associated with supermarket cluster

Suochen Tian; Min Wu; Zhenqin Chang; Yunxia Wang; Guijie Zhou; Wenming Zhang; Junmin Xing; Hui Tian; Xihong Zhang; Xiuli Zou; Lina Zhang; Mingxin Liu; Juan Chen; Jian Han; Kang Ning; Shuangfeng Chen; Tiejun Wu

During the outbreak, about 8,000 people were screened and a total of 24 COVID 19 patients were confirmed, including 11 supermarket employees and 13 employees' family members or friends (10 family members and 3 friends). No supermarket customers were diagnosed. All the cases associated with the supermarket cluster had no history of sojourn in the epidemic area, among which the secondary cases due to close contact had a history of close contact with the confirmed supermarket staff. 7 of the patients were asymptomatic, 6 of them were supermarket employees, and 3 of them caused 6 family members or friends to have symptoms. The onset time of symptomatic patients was concentrated between 5 and 11 days after the onset of symptoms in the first confirmed patient (figure I). Since it was difficult to determine the source of infection of the confirmed supermarket employees, which was identified as the common exposure, 3 generations of cases were generated in the clusters, including 11 cases in the first generation (11/24, 45.8%), 11 cases in the second generation (11/24, 45.8%), and 2 cases in the third generation (2/24, 8.3%) (figure II). The incubation period of these patients was also difficult to determine.