Fondazione Bruno Kessler, Trento, Italy.
University of Trento, Trento, Italy.
Nat Commun. 2021 Mar 12;12(1):1655. doi: 10.1038/s41467-021-21809-w.
Digital contact tracing is a relevant tool to control infectious disease outbreaks, including the COVID-19 epidemic. Early work evaluating digital contact tracing omitted important features and heterogeneities of real-world contact patterns influencing contagion dynamics. We fill this gap with a modeling framework informed by empirical high-resolution contact data to analyze the impact of digital contact tracing in the COVID-19 pandemic. We investigate how well contact tracing apps, coupled with the quarantine of identified contacts, can mitigate the spread in real environments. We find that restrictive policies are more effective in containing the epidemic but come at the cost of unnecessary large-scale quarantines. Policy evaluation through their efficiency and cost results in optimized solutions which only consider contacts longer than 15-20 minutes and closer than 2-3 meters to be at risk. Our results show that isolation and tracing can help control re-emerging outbreaks when some conditions are met: (i) a reduction of the reproductive number through masks and physical distance; (ii) a low-delay isolation of infected individuals; (iii) a high compliance. Finally, we observe the inefficacy of a less privacy-preserving tracing involving second order contacts. Our results may inform digital contact tracing efforts currently being implemented across several countries worldwide.
数字接触追踪是控制传染病爆发的一种相关工具，包括 COVID-19 疫情。早期评估数字接触追踪的工作忽略了影响传染病动力学的现实接触模式的重要特征和异质性。我们通过受经验丰富的高分辨率接触数据启发的建模框架来填补这一空白，以分析数字接触追踪在 COVID-19 大流行中的影响。我们研究了接触追踪应用程序（加上对已识别接触者的隔离）在真实环境中减轻传播的效果如何。我们发现，限制性政策在遏制疫情方面更有效，但代价是不必要的大规模隔离。通过效率和成本进行政策评估会产生仅考虑持续 15-20 分钟以上且距离 2-3 米以内的接触者的优化解决方案。我们的研究结果表明，当满足某些条件时，隔离和追踪可以帮助控制再次出现的疫情：（i）通过口罩和物理距离降低繁殖数；（ii）及时隔离感染者；（iii）高合规性。最后，我们观察到涉及二级接触者的隐私保护程度较低的追踪效果不佳。我们的研究结果可能会为目前在全球多个国家实施的数字接触追踪工作提供信息。
