Hao Lei1, Xifeng Wu1,2, Xiao Wang3, Modi Xu3, Yu Xie3, Xiangjun Du3, Benjamin J Cowling4, Yuguo Li5, Yuelong Shu3. 1. Department of Big Data in Health Science, School of Public Health, Zhejiang University, Hangzhou, P.R. China. 2. Center for Biostatistics, Bioinformatics, and Big Data, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China. 3. School of Public Health (Shenzhen), Sun Yat-sen University, Guangzhou, P.R. China. 4. World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, P.R. China. 5. Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, P.R. China.
Abstract
BACKGROUND: Nonpharmaceutical interventions (NPIs) against coronavirus disease 2019 (COVID-19) are vital to reducing transmission risks. However, the relative efficiency of social distancing against COVID-19 remains controversial, since social distancing and isolation/quarantine were implemented almost at the same time in China. METHODS: In this study, surveillance data of COVID-19 and seasonal influenza in 2018-2020 were used to quantify the relative efficiency of NPIs against COVID-19 in China, since isolation/quarantine was not used for the influenza epidemics. Given that the relative age-dependent susceptibility to influenza and COVID-19 may vary, an age-structured susceptible/infected/recovered model was built to explore the efficiency of social distancing against COVID-19 under different population susceptibility scenarios. RESULTS: The mean effective reproductive number, Rt, of COVID-19 before NPIs was 2.12 (95% confidence interval [CI], 2.02-2.21). By 11 March 2020, the overall reduction in Rt of COVID-19 was 66.1% (95% CI, 60.1-71.2%). In the epidemiological year 2019-20, influenza transmissibility was reduced by 34.6% (95% CI, 31.3-38.2%) compared with transmissibility in epidemiological year 2018-19. Under the observed contact pattern changes in China, social distancing had similar efficiency against COVID-19 in 3 different scenarios. By assuming the same efficiency of social distancing against seasonal influenza and COVID-19 transmission, isolation/quarantine and social distancing could lead to 48.1% (95% CI, 35.4-58.1%) and 34.6% (95% CI, 31.3-38.2%) reductions of the transmissibility of COVID-19, respectively. CONCLUSIONS: Though isolation/quarantine is more effective than social distancing, given that the typical basic reproductive number of COVID-19 is 2-3, isolation/quarantine alone could not contain the COVID-19 pandemic effectively in China.
BACKGROUND: Nonpharmaceutical interventions (NPIs) against coronavirus disease 2019 (COVID-19) are vital to reducing transmission risks. However, the relative efficiency of social distancing against COVID-19 remains controversial, since social distancing and isolation/quarantine were implemented almost at the same time in China. METHODS: In this study, surveillance data of COVID-19 and seasonal influenza in 2018-2020 were used to quantify the relative efficiency of NPIs against COVID-19 in China, since isolation/quarantine was not used for the influenza epidemics. Given that the relative age-dependent susceptibility to influenza and COVID-19 may vary, an age-structured susceptible/infected/recovered model was built to explore the efficiency of social distancing against COVID-19 under different population susceptibility scenarios. RESULTS: The mean effective reproductive number, Rt, of COVID-19 before NPIs was 2.12 (95% confidence interval [CI], 2.02-2.21). By 11 March 2020, the overall reduction in Rt of COVID-19 was 66.1% (95% CI, 60.1-71.2%). In the epidemiological year 2019-20, influenza transmissibility was reduced by 34.6% (95% CI, 31.3-38.2%) compared with transmissibility in epidemiological year 2018-19. Under the observed contact pattern changes in China, social distancing had similar efficiency against COVID-19 in 3 different scenarios. By assuming the same efficiency of social distancing against seasonal influenza and COVID-19 transmission, isolation/quarantine and social distancing could lead to 48.1% (95% CI, 35.4-58.1%) and 34.6% (95% CI, 31.3-38.2%) reductions of the transmissibility of COVID-19, respectively. CONCLUSIONS: Though isolation/quarantine is more effective than social distancing, given that the typical basic reproductive number of COVID-19 is 2-3, isolation/quarantine alone could not contain the COVID-19 pandemic effectively in China.
Authors: Shuxuan Song; Qian Li; Li Shen; Minghao Sun; Zurong Yang; Nuoya Wang; Jifeng Liu; Kun Liu; Zhongjun Shao Journal: Front Public Health Date: 2022-03-29