The effectiveness of social bubbles as part of a Covid-19 lockdown exit strategy, a modelling study.
The effectiveness of social bubbles as part of a Covid-19 lockdown exit strategy, a modelling study.
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DOI：
10.12688/wellcomeopenres.16164.2
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发表时间：
2020
影响因子：
--
通讯作者：
Flasche S
中科院分区：
文献类型：
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作者：
Leng T;White C;Hilton J;Kucharski A;Pellis L;Stage H;Davies NG;Centre for Mathematical Modelling of Infectious Disease 2019 nCoV Working Group;Keeling MJ;Flasche S
背景资料： 在2019冠状病毒病（COVID-19）封锁期间，社交泡沫中的接触者聚集可能允许以最小的额外风险将接触扩展到家庭以外，因此被视为经修改的封锁政策或逐步封锁退出策略的一部分。我们以英国为例，估计了这些策略对流行病和死亡风险的影响。 研究方法： 我们使用了一个基于个体的模型，用于类似于英国的合成人群，分层为来自社区、家庭内部和同一社会泡沫中其他家庭的传播风险。基本情况考虑的情况下，非必要的商店和学校关闭，第二次家庭攻击率为20%，初始繁殖数为0.8。我们模拟社会泡沫战略（两个家庭形成一个排他性的对）的家庭，包括儿童，单人居住的家庭，和所有的家庭。我们测试了结果对一系列替代模型假设和参数的敏感性。 结果如下：将家庭以外的接触者聚集成专属气泡是一种有效的策略，可以增加接触，同时限制相关的流行病风险增加。在基础案例中，与非聚集的联系人增加相比，社交泡沫使死亡率降低了42%。我们发现，如果所有家庭都形成社会泡沫，再生产数量可能会增加到R=1的流行阈值以上。允许有年幼子女的家庭或单身家庭形成社会泡沫的策略使再生产数量增加了不到11%。死亡率的相应增加与流行病风险的增加成比例，但集中在老年人中，而不管是否被纳入社会泡沫。 结论： 如果管理得当，社会泡沫可以成为一种有效的方式，将接触范围扩大到家庭以外，同时限制流行病风险的增加。
Background: During the coronavirus disease 2019 (COVID-19) lockdown, contact clustering in social bubbles may allow extending contacts beyond the household at minimal additional risk and hence has been considered as part of modified lockdown policy or a gradual lockdown exit strategy. We estimated the impact of such strategies on epidemic and mortality risk using the UK as a case study. Methods: We used an individual based model for a synthetic population similar to the UK, stratified into transmission risks from the community, within the household and from other households in the same social bubble. The base case considers a situation where non-essential shops and schools are closed, the secondary household attack rate is 20% and the initial reproduction number is 0.8. We simulate social bubble strategies (where two households form an exclusive pair) for households including children, for single occupancy households, and for all households. We test the sensitivity of results to a range of alternative model assumptions and parameters. Results: Clustering contacts outside the household into exclusive bubbles is an effective strategy of increasing contacts while limiting the associated increase in epidemic risk. In the base case, social bubbles reduced fatalities by 42% compared to an unclustered increase of contacts. We find that if all households were to form social bubbles the reproduction number would likely increase to above the epidemic threshold of R=1. Strategies allowing households with young children or single occupancy households to form social bubbles increased the reproduction number by less than 11%. The corresponding increase in mortality is proportional to the increase in the epidemic risk but is focussed in older adults irrespective of inclusion in social bubbles. Conclusions: If managed appropriately, social bubbles can be an effective way of extending contacts beyond the household while limiting the increase in epidemic risk.