School of Mathematics and Statistics, University of Canterbury, Christchurch, 8140, New Zealand.Te Pūnaha Matatini: Centre of Research Excellence in Complex Systems, Auckland, 1142, New Zealand.
Manaaki Whenua, Lincoln, 7640, New Zealand.
Math Med Biol. 2022 Jun 11;39(2):156-168. doi: 10.1093/imammb/dqac002.
Digital tools are being developed to support contact tracing as part of the global effort to control the spread of COVID-19. These include smartphone apps, Bluetooth-based proximity detection, location tracking and automatic exposure notification features. Evidence on the effectiveness of alternative approaches to digital contact tracing is so far limited.
We use an age-structured branching process model of the transmission of COVID-19 in different settings to estimate the potential of manual contact tracing and digital tracing systems to help control the epidemic. We investigate the effect of the uptake rate and proportion of contacts recorded by the digital system on key model outputs: the effective reproduction number, the mean outbreak size after 30 days and the probability of elimination.
Effective manual contact tracing can reduce the effective reproduction number from 2.4 to around 1.5. The addition of a digital tracing system with a high uptake rate over 75% could further reduce the effective reproduction number to around 1.1. Fully automated digital tracing without manual contact tracing is predicted to be much less effective.
For digital tracing systems to make a significant contribution to the control of COVID-19, they need be designed in close conjunction with public health agencies to support and complement manual contact tracing by trained professionals.
为了控制 COVID-19 的传播，全球正在开发数字工具来支持接触者追踪。这些工具包括智能手机应用程序、基于蓝牙的近距离检测、位置跟踪和自动暴露通知功能。到目前为止，有关替代数字接触者追踪方法的有效性的证据有限。
我们使用不同环境下 COVID-19 传播的年龄结构分支过程模型来估计手动接触者追踪和数字追踪系统帮助控制疫情的潜力。我们调查了数字系统记录的接触者的吸收率和比例对关键模型输出的影响：有效繁殖数、30 天后的平均爆发规模和消除概率。
有效的手动接触者追踪可以将有效繁殖数从 2.4 降低到 1.5 左右。如果添加一个吸收率超过 75%的高吸收率数字追踪系统，则可以进一步将有效繁殖数降低到 1.1 左右。如果没有手动接触者追踪的完全自动化数字追踪，预计效果会差得多。
为了使数字追踪系统对 COVID-19 的控制做出重大贡献，它们需要与公共卫生机构密切合作，以支持和补充经过培训的专业人员的手动接触者追踪。
