Food-trade-associated COVID-19 outbreak from a contaminated wholesale food supermarket in Beijing

Lu, Shan; Wang, Weijia; Cheng, Yanpeng; Yang, Caixin; Jiao, Yifan; Xu, Mingchao; Bai, Yibo; Yang, Jing; Song, Hongbin; Wang, Ligui; Wang, Jiaojiao; Rong, Bing; Xu, Jianguo

The re-emerging outbreak of COVID-19 in Beijing, China, in the summer of 2020 originated from a SARS-CoV-2-infested wholesale food supermarket. We postulated that the Xinfadi market outbreak has links with food-trade activities. Our Susceptible to the disease, Infectious, and Recovered coupled Agent Based Modelling (SIR-ABM) analysis for studying the diffusion of SARS-CoV-2 particles suggested that the trade-distancing strategy effectively reduces the reproduction number (R0). The retail shop closure strategy reduced the number of visitors to the market by nearly half. In addition, the buy-local policy option reduced the infection by more than 70% in total. Therefore, retail closures and buy-local policies could serve as significantly effective strategies that have the potential to reduce the size of the outbreak and prevent probable outbreaks in the future.