Yang Ge1, Zhiping Chen2, Andreas Handel3, Leonardo Martinez4, Qian Xiao5, Changwei Li6, Enfu Chen2, Jinren Pan2, Yang Li7, Feng Ling8, Ye Shen9. 1. University of Georgia, College of Public Health, Department of Epidemiology and Biostatistics, Athens, Georgia, United States. 2. Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China. 3. University of Georgia, College of Public Health, Department of Epidemiology and Biostatistics, Athens, Georgia, United States; University of Georgia, College of Public Health, Health Informatics Institute, Athens, Georgia, United States; University of Georgia, Center for the Ecology of Infectious Diseases, Athens, Georgia, United States. 4. Boston University, School of Public Health, Department of Epidemiology, Boston, Massachusetts, United States. 5. University of Georgia, Department of Statistics, Athens, Georgia, United States. 6. University of Georgia, College of Public Health, Department of Epidemiology and Biostatistics, Athens, Georgia, United States; Tulane University, School of Public Health and Tropical Medicine, Department of Epidemiology, New Orleans, Louisiana, United States. 7. Renmin University of China, Center for Applied Statistics, Beijing, China; Renmin University of China, School of Statistics, Beijing, China; Renmin University of China, Statistical Consulting Center, Beijing, China. Electronic address: yang.li@ruc.edu.cn. 8. Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China. Electronic address: fengl@cdc.zj.cn. 9. University of Georgia, College of Public Health, Department of Epidemiology and Biostatistics, Athens, Georgia, United States. Electronic address: yeshen@uga.edu.
Abstract
INTRODUCTION: Most countries are dependent on nonpharmaceutical public health interventions such as social distancing, contact tracing, and case isolation to mitigate COVID-19 spread until medicines or vaccines widely available. Minimal research has been performed on the independent and combined impact of each of these interventions based on empirical case data. METHODS: We obtained data from all confirmed COVID-19 cases from January 7th to February 22nd 2020 in Zhejiang Province, China, to fit an age-stratified compartmental model using human contact information before and during the outbreak. The effectiveness of social distancing, contact tracing, and case isolation was studied and compared in simulation. We also simulated a two-phase reopening scenario to assess whether various strategies combining nonpharmaceutical interventions are likely to achieve population-level control of a second-wave epidemic. RESULTS: Our study sample included 1,218 symptomatic cases with COVID-19, of which 664 had no inter-province travel history. Results suggest that 36.5 % (95 % CI, 12.8-57.1) of contacts were quarantined, and approximately five days (95 % CI, 2.2-11.0) were needed to detect and isolate a case. As contact networks would increase after societal and economic reopening, avoiding a second wave without strengthening nonpharmaceutical interventions compared to the first wave it would be exceedingly difficult. CONCLUSIONS: Continuous attention and further improvement of nonpharmaceutical interventions are needed in second-wave prevention. Specifically, contact tracing merits further attention.
INTRODUCTION: Most countries are dependent on nonpharmaceutical public health interventions such as social distancing, contact tracing, and case isolation to mitigate COVID-19 spread until medicines or vaccines widely available. Minimal research has been performed on the independent and combined impact of each of these interventions based on empirical case data. METHODS: We obtained data from all confirmed COVID-19 cases from January 7th to February 22nd 2020 in Zhejiang Province, China, to fit an age-stratified compartmental model using human contact information before and during the outbreak. The effectiveness of social distancing, contact tracing, and case isolation was studied and compared in simulation. We also simulated a two-phase reopening scenario to assess whether various strategies combining nonpharmaceutical interventions are likely to achieve population-level control of a second-wave epidemic. RESULTS: Our study sample included 1,218 symptomatic cases with COVID-19, of which 664 had no inter-province travel history. Results suggest that 36.5 % (95 % CI, 12.8-57.1) of contacts were quarantined, and approximately five days (95 % CI, 2.2-11.0) were needed to detect and isolate a case. As contact networks would increase after societal and economic reopening, avoiding a second wave without strengthening nonpharmaceutical interventions compared to the first wave it would be exceedingly difficult. CONCLUSIONS: Continuous attention and further improvement of nonpharmaceutical interventions are needed in second-wave prevention. Specifically, contact tracing merits further attention.
Authors: Hugo Saba; A S Nascimento Filho; José G V Miranda; Raphael S Rosário; Thiago B Murari; Eduardo M F Jorge; Elaine C B Cambui; Márcia S P L Souza; Ana C F N Silva; Márcio L V Araújo Journal: Epidemics Date: 2022-06-01 Impact factor: 5.324