Impact of physical distancing policy on reducing transmission of SARS-CoV-2 globally: Perspective from government’s response and residents’ compliance

Abstract

Background COVID-19 was declared a public health emergency by the World Health Organization (WHO) in January 2020. Various physical distancing interventions were introduced to flatten the epidemic curve and reduce the disease burden. We evaluated the impacts of policy stringency and residents’ compliance on time-varying reproduction number in 17 countries. Methods Data were from WHO reports of local transmission (February 28 to April 8, 2020) in Australia, Canada, Finland, France, Germany, Greece, Italy, Spain, Sweden, Thailand, the UK, US and Vietnam. Earlier local transmission data where available from press releases were added for Japan, South Korea, Singapore and Taiwan starting January 28, 2020. COVID-19 policy responses were from the Oxford Covid-19 Government Response Tracker with 17 indicators. Changes in people’s behaviors were from Google’s COVID-19 community mobility reports and Apple Maps’ mobility trends reports. We estimated the daily time-varying reproduction number (Rt) by country. 0-, 7- and 14-day lagged effects of non-pharmaceutical interventions and changes in human mobility on Rt were estimated by linear mixed-effects models. Results Rt initially surged rapidly, then declined gradually depending on policy stringency. The highest mean policy stringency scores were for Italy (69.97) and South Korea (61.00). Variations in stringency scores were higher in Europe, the US and Australia than in Asia. The human mobility reduction was greater in countries with strict policies (median stringency score > = 50). In terms of immediate (0-day lag) effects, Rt reductions were found for workplace-closure, limited-gathering, and stay-at-home policies. At a 7-day lag, Rt reductions were found for workplace closure, restrictions on gatherings, stay-at-home requirements, international travel controls, contact tracing and reducing walking around. At a 14-day lag, Rt reductions were found for restrictions on gatherings, less visiting and staying in parks, and reduced walking around. Conclusion The findings show physical distancing policies and residents’ compliance can slow transmission, with the lag-to-effect time varying by policy.

Air Pollution Mediates the Association between Human Mobility and COVID-19 Infection

“…* p < 0.05. pollution. The 7-day lag effect on the newly confirmed COVID-19 cases and mortality was reported in previous studies (Wang et al, 2020a;Chung and Chan, 2021;Dales et al, 2021). Previous findings showed that 10 µg m -3 increase in PM 2.5 was associated with the confirmed cases of COVID-19, and the estimated strongest relative risk were observed at 7-day lag (Wang et al, 2020a).…”

Animal-vehicle collisions during the COVID-19 lockdown in early 2020 in the Krakow metropolitan region, Poland

“…Declared a global pandemic in March 2020, the outbreak of COVID-19 caused by the novel coronavirus SARS-CoV-2 in early 2020 brought about major changes to human dynamics on a global scale 4 . Governments restricted people’s mobility through stay at home requirements termed “lockdowns” 5 to prevent the spread of disease 6 .…”

A combined model for COVID-19 pandemic control: The application of Haddon's matrix and community risk reduction tools combined

“…At this stage, the community’s level of compliance is essential, whether the compliance is towards preventive measures for healthy individuals or towards isolation instructions for the infected individuals. In addition, social gatherings and non-complying to physical distancing would increase COVID-19 transmission [50] , [51] . Moreover, social behaviors in small or mass gatherings play an important role in managing the rate of transmission.…”