【Abstract】
BACKGROUND:The time of the COVID-19 outbreak in Wuhan coincided with the Chinese Spring Festival, when the largest annual population movement began. Before the lockdown on January 23rd, an estimated 5 million residents left Wuhan. The infected people in incubation period had brought the virus to other cities and person-to-person transmission of the new coronavirus caused the spread of infections across the country.
METHODS:We searched daily flights, buses, and trains from Wuhan to these cities in January. We also obtained straight line distances between Wuhan and these cities. The daily number and the cumulative number of COVID-19 cases in each city were obtained from the official website. All the data were logarithmically transformed and the Pearson´s correlation analysis was used to examine correlations of daily frequencies of each transportation methods and the distance between Wuhan and other cities, with the daily number and the cumulative number of COVID-19 cases.
RESULTS:We found a significant and positive association between the frequency of flights, trains, and buses from Wuhan and the daily as well as the cumulative numbers of COVID-19 cases in other cities with progressively increased correlations for trains and buses (all P values < 0.001). The distance between Wuhan and other cities was inversely associated with the numbers of COVID-19 cases in that city (all P values < 0.001), and the correlation became increasingly stronger and went stable after February 1st.
CONCLUSIONS:Our findings indicated that imported cases via public transportation played an important role in the spread of COVID-19. The connectivity and distance between the epicenter and the destination are important determinants of transmission risks. Strong preventive measures should be taken in cities with shorter distances and more frequent public transportation connectivity with epicenter in order to contain input and output of the COVID-19 epidemic.
【中文摘要】
背景：武汉封城前恰逢春运时间，估计有500万人离开武汉前往全国各地，对新型冠状病毒肺炎的疫情蔓延产生影响。
方法：本研究通过每日网络实时报告的新型冠状病毒肺炎疫情数据获得各地市的每日新增及累计病例数，检索在武汉封城前2周内，由武汉发出到各地市的每日飞机航班数、客运汽车班次数、火车列次数，并获得各地市与武汉的直线距离。
结果：研究发现新型冠状病毒肺炎每日新增病例数和累计病例数，与由武汉发出到达各地市的每日飞机航班数、客运汽车班次数、火车列次数呈正相关，与武汉距各地的直线距离呈负相关。随着疫情的进展上述相关性逐渐增强，并在2月1日后趋于稳定。另外，新型冠状病毒肺炎每日新增病例数和累计病例数与汽车及火车频次的相关性强于飞机航班数。
结论：公共交通在新型冠状病毒肺炎传播中具有重要影响，也是控制传染病蔓延的关键。与新型冠状病毒肺炎疫情爆发点之间的交通越便利，或距离越近的地市应采取更加严格的防范措施。