Worldwide COVID-19 spreading explained: traveling numbers as a primary driver for the pandemic

Abstract The spread of SARS-CoV-2 and the distribution of cases worldwide followed no clear biogeographic, climatic, or cultural trend. Conversely, the internationally busiest cities in all countries tended to be the hardest hit, suggesting a basic, mathematically neutral pattern of the new coronavirus early dissemination. We tested whether the number of flight passengers per time and the number of international frontiers could explain the number of cases of COVID-19 worldwide by a stepwise regression. Analysis were taken by 22 May 2020, a period when one would claim that early patterns of the pandemic establishment were still detectable, despite of community transmission in various places. The number of passengers arriving in a country and the number of international borders explained significantly 49% of the variance in the distribution of the number of cases of COVID-19, and number of passengers explained significantly 14.2% of data variance for cases per million inhabitants. Ecological neutral theory may explain a considerable part of the early distribution of SARS-CoV-2 and should be taken into consideration to define preventive international actions before a next pandemic.摘要 严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）的传播及其全球病例分布未呈现清晰的生物地理、气候或文化趋势。与之相反，全球各国国际客运量最高的城市往往受疫情冲击最为严重，这提示新型冠状病毒早期传播存在一种基础的、数学上中性的传播模式。本研究通过逐步回归分析，验证了单位时间航班客运量与国际边境数量能否解释全球新型冠状病毒肺炎（COVID-19）的病例数。本次分析截至2020年5月22日，彼时尽管多地已出现社区传播，但疫情早期的流行模式仍可被观测到。研究结果表明，入境一国的客运量与国际边境数量可显著解释49%的COVID-19病例分布方差；而针对每百万人口的病例数数据，客运量可显著解释其中14.2%的方差。生态中性理论（Ecological Neutral Theory）或可解释SARS-CoV-2早期全球分布的相当一部分成因，在制定下一次大流行病前的国际防控措施时，应将该理论纳入考量范畴。