Implication of backward contact tracing in the presence of overdispersed transmission in COVID-19 outbreaks.
Implication of backward contact tracing in the presence of overdispersed transmission in COVID-19 outbreaks.
复制标题
在Covid-19爆发中存在过度传播的情况下，向后接触的含义。
DOI：
10.12688/wellcomeopenres.16344.3
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发表时间：
2020
影响因子：
--
通讯作者：
Kucharski AJ
中科院分区：
文献类型：
--
作者：
Endo A;Centre for the Mathematical Modelling of Infectious Diseases COVID-19 Working Group;Leclerc QJ;Knight GM;Medley GF;Atkins KE;Funk S;Kucharski AJ
简介：接触者追踪有可能控制疫情，而不需要严格的物理距离政策，例如民事封锁。与正向接触者追踪不同，反向接触者追踪确定新发现病例的来源。当二次传输的数量存在较高的个体级别差异(过度分散)时，这种方法特别有价值。方法：利用一个简单的分枝过程模型，探索反向接触者追踪与更传统的正向接触者追踪相结合控制新冠肺炎的可能性。我们估计了回溯跟踪可以达到的典型簇的大小，并模拟了回溯跟踪和传统前向跟踪相结合的增量效果。结果：在与SARS-CoV-2动态一致的参数值范围内，回溯追踪有望识别出一个初始病例产生的感染是随机选择的病例的3-10倍，通常将避免后续病例的比例增加2-3倍。通过回溯追踪避免的病例估计数量随着过度分散程度的提高而变得更大。结论：反向接触者追踪是控制暴发的有效工具，特别是在SARS-CoV-2所观察到的过度扩散的情况下。
Introduction: Contact tracing has the potential to control outbreaks without the need for stringent physical distancing policies, e.g. civil lockdowns. Unlike forward contact tracing, backward contact tracing identifies the source of newly detected cases. This approach is particularly valuable when there is high individual-level variation in the number of secondary transmissions (overdispersion). Methods: By using a simple branching process model, we explored the potential of combining backward contact tracing with more conventional forward contact tracing for control of COVID-19. We estimated the typical size of clusters that can be reached by backward tracing and simulated the incremental effectiveness of combining backward tracing with conventional forward tracing. Results: Across ranges of parameter values consistent with dynamics of SARS-CoV-2, backward tracing is expected to identify a primary case generating 3-10 times more infections than a randomly chosen case, typically increasing the proportion of subsequent cases averted by a factor of 2-3. The estimated number of cases averted by backward tracing became greater with a higher degree of overdispersion. Conclusion: Backward contact tracing can be an effective tool for outbreak control, especially in the presence of overdispersion as is observed with SARS-CoV-2.