Ziegler Zvi
Professor Emeritus, Department of Mathematics, Technion-Israel Institute of Technology, Haifa, Israel.
Rambam Maimonides Med J. 2020 Jul 31;11(3):e0021. doi: 10.5041/RMMJ.10410.
The coronavirus disease-2019 (COVID-19) epidemic started in late 2019, and was upgraded to a pandemic on March 11, 2020 by the World Health Organization (WHO). Well established epidemiological models have been used over the last few months in an attempt to predict how the virus would spread. The predictions were frightening, and the resulting panic caused many governments to impose lockdowns or other severe restrictions, with lasting effects. This short paper discusses another way of looking at the spread of COVID-19, by focusing on the daily rate of infection, defined as the daily rate of increase in the number of infected persons. It is shown that the daily rate is monotonically decreasing, after a short initial period, in all countries, and that the pattern is similar in all countries. This appears to be a universal phenomenon. Based on these calculations, the April 1, 2020 data for Western Europe were sufficient to predict the beginning of the end of COVID-19 in that region before the end of that month.
2019冠状病毒病（COVID-19）疫情始于2019年末，2020年3月11日世界卫生组织（WHO）将其升级为大流行。在过去几个月里，人们使用了成熟的流行病学模型来预测病毒的传播方式。预测结果令人恐惧，由此引发的恐慌导致许多政府实施封锁或其他严格限制措施，并产生了持久影响。这篇短文通过关注每日感染率（定义为感染人数的每日增加率）来探讨看待COVID-19传播的另一种方式。结果表明，在经过短暂的初始阶段后，所有国家的每日感染率都在单调下降，且各国的模式相似。这似乎是一个普遍现象。基于这些计算，2020年4月1日西欧的数据足以预测该地区COVID-19在当月月底前结束的开始时间。
