Impact of self-imposed prevention measures and short-term government-imposed social distancing on mitigating and delaying a COVID-19 epidemic: A modelling study

Abstract

1Background: With new cases of COVID-19 surging around the world, many countries have to prepare for mov-2 ing beyond the containment phase. Prediction of the effectiveness of non-case-based interventions for mitigating, 3 delaying or preventing the epidemic is urgent, especially for countries affected by the ongoing seasonal influenza 4 activity. 5Methods:We developed a transmission model to evaluate the impact of self-imposed prevention measures 6 (handwashing, mask-wearing, and social distancing) due to the spread of COVID-19 awareness and of short-7 term government-imposed social distancing on the peak number of diagnoses, attack rate and time until the 8 peak number of diagnoses. 9 Findings: For fast awareness spread in the population, self-imposed measures can significantly reduce the attack 10 rate, diminish and postpone the peak number of diagnoses. A large epidemic can be prevented if the efficacy 11 of these measures exceeds 50%. For slow awareness spread, self-imposed measures reduce the peak number 12 of diagnoses and attack rate but do not affect the timing of the peak. Early implementation of short-term 13 government interventions can only delay the peak (by at most 7 months for a 3-month intervention). 14 Interpretation:Handwashing, mask-wearing and social distancing as a reaction to information dissemination 15 about COVID-19 can be effective strategies to mitigate and delay the epidemic. We stress the importance of 16 rapidly spreading awareness on the use of these self-imposed prevention measures in the population. Early-17 initiated short-term government-imposed social distancing can buy time for healthcare systems to prepare for 18 an increasing COVID-19 burden.Evidence to date suggests that containment of SARS-CoV-2 using quarantine, travel restrictions, isolation of symp-26 tomatic cases, and contact tracing may need to be supplemented by other interventions. Given its rapid spread 27 across the world and immense implications for public health, it is urgent to understand whether non-case-based 28 interventions can mitigate, delay or even prevent a COVID-19 epidemic. One such strategy is a broader-scale 29 contact rate reduction enforced by governments which was used during previous outbreaks, e.g., the 1918 influenza 30 pandemic and the 2009 influenza A/H1N1 pandemic in Mexico. Alternatively, governments and media may stimu-31 late self-imposed prevention measures (handwashing, mask-wearing, and social distancing) by generating awareness 32 about COVID-19, especially when economic and societal consequences are taken into account. Both of these strate-33 gies may have a significant impact on the outbreak dynamics. Currently, there are no comparative studies that 34 investigate their viability for controlling a COVID-19 epidemic. 35Added value of this study 36 Using a transmission model parameterized with current best estimates of epidemiological parameters, we evaluated 37 the impact of handwashing, mask-wearing, and social distancing due to COVID-19 awareness and of government-38 imposed soc...

Evaluating the impact of stay-at-home orders on the time to reach the peak burden of Covid-19 cases and deaths: does timing matter?

“…Contrary to our findings, a recent deterministic compartmental transmission modeling study found that short-term government-imposed social distancing alone would delay but not reduce the peak number of COVID-19 diagnoses [ 30 ]. These authors proposed that more timely imposed social distancing may be beneficial by allowing time for healthcare systems and public health regional leaders to prepare for an increasing burden of cases [ 30 ]. Conversely, one may argue that earlier peaks may instead be preferrable from a public health perspective, since overall case counts may be subsequently lower.…”

Social distancing to slow the U.S. COVID-19 epidemic: longitudinal pretest-posttest comparison group study

“…In response, state governments in the United States have applied social distancing measures in an attempt to limit transmission and reduce morbidity and mortality. Such measures have been applied during prior pandemics, with moderate success (2)(3)(4), and are predicted to prevent a rapid, overwhelming epidemic in modeling studies (5). However, the extent to which social distancing measures have influenced the course of the COVID-19 pandemic has not been established.…”

Can self-imposed prevention measures mitigate the COVID-19 epidemic?

“…To date, as least 6 countries, including China, Germany, Iran, South Korea, Lebanon, and Saudi Arabia, have experienced some resurgence of the epidemic after lifting the lockdown. The work by Teslya and colleagues is particularly relevant to the Chinese experience and suggests that the very successful government-initiated social distancing measures may, at best, delay the epidemic for months [ 2 ]. But what Teslya and colleagues’ modelling implies is that with high levels of self-imposed prevention measures, a second epidemic may not occur.…”