Yau Mathematical Science Center, Tsinghua University.
HuaHuiChangTian (Beijing) Information Technology Co., Ltd.
Medicine (Baltimore). 2021 Feb 5;100(5):e23925. doi: 10.1097/MD.0000000000023925.
The World Health Organization (WHO) classified the spread of COVID-19 (Coronavirus Disease 2019) as a global pandemic in March. Scholars predict that the pandemic will continue into the coming winter and will become a seasonal epidemic in the following year. Therefore, the identification of effective control measures becomes extremely important. Although many reports have been published since the COVID-19 outbreak, no studies have identified the relative effectiveness of a combination of control measures implemented in Wuhan and other areas in China. To this end, a retrospective analysis by the collection and modeling of an unprecedented number of epidemiology records in China of the early stage of the outbreaks can be valuable.In this study, we developed a new dynamic model to describe the spread of COVID-19 and to quantify the effectiveness of control measures. The transmission rate, daily close contacts, and the average time from onset to isolation were identified as crucial factors in viral spreading. Moreover, the capacity of a local health-care system is identified as a threshold to control an outbreak in its early stage. We took these factors as controlling parameters in our model. The parameters are estimated based on epidemiological reports from national and local Center for Disease Control (CDCs).A retrospective simulation showed the effectiveness of combinations of 4 major control measures implemented in Wuhan: hospital isolation, social distancing, self-protection by wearing masks, and extensive medical testing. Further analysis indicated critical intervention conditions and times required to control an outbreak in the early stage. Our simulations showed that South Korea has kept the spread of COVID-19 at a low level through extensive medical testing. Furthermore, a predictive simulation for Italy indicated that Italy would contain the outbreak in late May under strict social distancing.In our general analysis, no single measure could contain a COVID-19 outbreak once a health-care system is overloaded. Extensive medical testing could keep viral spreading at a low level. Wearing masks functions as favorably as social distancing but with much lower socioeconomic costs.
世界卫生组织（WHO）于 3 月将 COVID-19（2019 年冠状病毒病）的传播归类为全球大流行。学者们预测，大流行将持续到未来的冬季，并在次年成为季节性流行。因此，确定有效的控制措施变得非常重要。虽然自 COVID-19 爆发以来已经有许多报告发表，但没有研究确定中国武汉和其他地区实施的综合控制措施的相对效果。为此，通过收集和建立中国疫情爆发早期前所未有的流行病学记录模型进行回顾性分析可能具有重要价值。在这项研究中，我们开发了一种新的动态模型来描述 COVID-19 的传播，并量化控制措施的有效性。传播率、日常密切接触者以及从发病到隔离的平均时间被确定为病毒传播的关键因素。此外，当地卫生保健系统的能力被确定为在早期控制疫情的一个阈值。我们将这些因素作为模型中的控制参数。这些参数是根据国家和地方疾病控制中心（CDC）的流行病学报告来估计的。回顾性模拟显示了在中国武汉实施的 4 项主要控制措施的组合的有效性：医院隔离、社会疏远、戴口罩自我保护和广泛的医学检测。进一步的分析表明了在早期控制疫情所需的关键干预条件和时间。我们的模拟表明，韩国通过广泛的医学检测将 COVID-19 的传播保持在较低水平。此外，对意大利的预测模拟表明，如果实施严格的社会隔离，意大利将在 5 月底控制疫情。在我们的总体分析中，一旦卫生保健系统不堪重负，没有单一的措施可以控制 COVID-19 的爆发。广泛的医学检测可以使病毒传播保持在较低水平。戴口罩的效果与社会隔离一样好，但社会经济成本要低得多。
