The implications of silent transmission for the control of COVID-19 outbreaks
The implications of silent transmission for the control of COVID-19 outbreaks
复制标题
DOI：
10.1073/pnas.2008373117
复制
发表时间：
2020-07-28
影响因子：
11.1
通讯作者：
Galvani, Alison P.
中科院分区：
文献类型：
--
作者：
Moghadas, Seyed M.;Fitzpatrick, Meagan C.;Galvani, Alison P.
自2019冠状病毒病（COVID-19）出现以来，全球范围内实施了前所未有的行动限制和社交距离措施。社会经济影响引发了取消这些措施的呼声。在没有人群限制的情况下，隔离感染者是减少传播的关键。然而，基于病毒的隔离在防止死灰复燃方面的有效性取决于症状前和无症状传播的程度。我们评估症状前和无症状传播的贡献的基础上，最近的个人水平的数据，在症状发作前的传染性和所有感染中的无症状的比例。我们发现，大多数的发病率可能是由于沉默的传播，从一个组合的症状前阶段和无症状感染。因此，即使所有有症状的病例都被隔离，仍可能出现大规模疫情。我们进一步量化了除了有症状的病例之外隔离无症状感染的效果，发现必须隔离超过三分之一的无症状感染，才能将未来的疫情控制在1%以下。我们的研究结果表明，以埃博拉病毒为基础的隔离必须辅之以快速接触者追踪和检测，以识别无症状和症状前病例，以便安全地解除目前的限制，并最大限度地减少死灰复燃的风险。
Since the emergence of coronavirus disease 2019 (COVID-19), unprecedented movement restrictions and social distancing measures have been implemented worldwide. The socioeconomic repercussions have fueled calls to lift these measures. In the absence of population-wide restrictions, isolation of infected individuals is key to curtailing transmission. However, the effectiveness of symptom-based isolation in preventing a resurgence depends on the extent of presymptomatic and asymptomatic transmission. We evaluate the contribution of presymptomatic and asymptomatic transmission based on recent individual-level data regarding infectiousness prior to symptom onset and the asymptomatic proportion among all infections. We found that the majority of incidences may be attributable to silent transmission from a combination of the presymptomatic stage and asymptomatic infections. Consequently, even if all symptomatic cases are isolated, a vast outbreak may nonetheless unfold. We further quantified the effect of isolating silent infections in addition to symptomatic cases, finding that over one-third of silent infections must be isolated to suppress a future outbreak below 1% of the population. Our results indicate that symptom-based isolation must be supplemented by rapid contact tracing and testing that identifies asymptomatic and presymptomatic cases, in order to safely lift current restrictions and minimize the risk of resurgence.