Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
PLoS One. 2021 Jan 6;16(1):e0244537. doi: 10.1371/journal.pone.0244537. eCollection 2021.
The unprecedented worldwide social distancing response to COVID-19 resulted in a quick reversal of escalating case numbers. Recently, local governments globally have begun to relax social distancing regulations. Using the situation in Manitoba, Canada as an example, we estimated the impact that social distancing relaxation may have on the pandemic.
We fit a mathematical model to empirically estimated numbers of people infected, recovered, and died from COVID-19 in Manitoba. We then explored the impact of social distancing relaxation on: (a) time until near elimination of COVID-19 (< one case per million), (b) time until peak prevalence, (c) proportion of the population infected within one year, (d) peak prevalence, and (e) deaths within one year.
Assuming a closed population, near elimination of COVID-19 in Manitoba could have been achieved in 4-6 months (by July or August) if there were no relaxation of social distancing. Relaxing to 15% of pre-COVID effective contacts may extend the local epidemic for more than two years (median 2.1). Relaxation to 50% of pre-COVID effective contacts may result in a peak prevalence of 31-38% of the population, within 3-4 months of initial relaxation.
Slight relaxation of social distancing may immensely impact the pandemic duration and expected peak prevalence. Only holding the course with respect to social distancing may have resulted in near elimination before Fall of 2020; relaxing social distancing to 15% of pre-COVID-19 contacts will flatten the epidemic curve but greatly extend the duration of the pandemic.
由于 COVID-19 大流行，全球前所未有的社会疏离响应导致病例数量迅速上升。最近，全球各地的地方政府开始放宽社会疏离规定。我们以加拿大马尼托巴省为例，估计社会疏离放松对大流行的影响。
我们使用数学模型对马尼托巴省 COVID-19 的感染、康复和死亡人数进行了实证估计。然后，我们探讨了社会疏离放松对以下方面的影响：（a）接近消除 COVID-19（每百万人中不到一例）所需的时间，（b）达到流行高峰所需的时间，（c）一年内感染人口的比例，（d）流行高峰，以及（e）一年内的死亡人数。
假设人口封闭，如果不放松社会疏离，马尼托巴省可能在 4-6 个月内（到 7 月或 8 月）就能消除 COVID-19。将社交距离放松到 COVID-19 前的有效接触量的 15%可能会使当地疫情延长两年以上（中位数为 2.1）。将社交距离放松到 COVID-19 前的有效接触量的 50%可能会导致 3-4 个月内人口的流行高峰率达到 31-38%。
对社会疏离的轻微放松可能会极大地影响大流行的持续时间和预期的流行高峰率。只有坚持社会距离的原则，才能在 2020 年秋季之前接近消除疫情；将社会距离放松到 COVID-19 前接触量的 15%，可以使疫情曲线变平，但会大大延长大流行的持续时间。
