Bioinformatics, Scientific Institute IRCCS E. MEDEA, 23842 Bosisio Parini, Italy.
Department of Biotechnology and Biosciences, University of Milan-Bicocca, 20126 Milan, Italy.
Viruses. 2022 May 19;14(5):1095. doi: 10.3390/v14051095.
Four endemic coronaviruses infect humans and cause mild symptoms. Because previous analyses were based on a limited number of sequences and did not control for effects that affect molecular dating, we re-assessed the timing of endemic coronavirus emergence. After controlling for recombination, selective pressure, and molecular clock model, we obtained similar tMRCA (time to the most recent common ancestor) estimates for the four coronaviruses, ranging from 72 (HCoV-229E) to 54 (HCoV-NL63) years ago. The split times of HCoV-229E and HCoV-OC43 from camel alphacoronavirus and bovine coronavirus were dated ~268 and ~99 years ago. The split times of HCoV-HKU1 and HCoV-NL63 could not be calculated, as their zoonoticic sources are unknown. To compare the timing of coronavirus emergence to that of another respiratory virus, we recorded the occurrence of influenza pandemics since 1500. Although there is no clear relationship between pandemic occurrence and human population size, the frequency of influenza pandemics seems to intensify starting around 1700, which corresponds with the initial phase of exponential increase of human population and to the emergence of HCoV-229E. The frequency of flu pandemics in the 19th century also suggests that the concurrence of HCoV-OC43 emergence and the Russian flu pandemic may be due to chance.
四种地方性冠状病毒感染人类并引起轻微症状。由于以前的分析基于有限数量的序列，并且没有控制影响分子定年的因素，因此我们重新评估了地方性冠状病毒的出现时间。在控制重组、选择压力和分子钟模型后，我们获得了四种冠状病毒相似的 tMRCA（最近共同祖先的时间）估计值，范围从 72 年前（HCoV-229E）到 54 年前（HCoV-NL63）。HCoV-229E 和 HCoV-OC43 与骆驼α冠状病毒和牛冠状病毒的分离时间分别约为 268 年前和 99 年前。由于其人畜共患病源未知，因此无法计算 HCoV-HKU1 和 HCoV-NL63 的分离时间。为了比较冠状病毒出现的时间与另一种呼吸道病毒的出现时间，我们记录了自 1500 年以来流感大流行的发生情况。尽管流感大流行的发生与人类人口规模之间没有明显的关系，但流感大流行的频率似乎从 1700 年左右开始加剧，这与人类人口指数增长的初始阶段以及 HCoV-229E 的出现相对应。19 世纪流感大流行的频率也表明，HCoV-OC43 出现与俄罗斯流感大流行的并发可能是偶然的。
