High intensities of population movement were associated with high incidence of COVID-19 during the pandemic

• Published in: Epidemiology and infection Vol. 148; p. e177
• Main Authors: Yang, Huikuan, Chen, Dandan, Jiang, Qunfang, Yuan, Zhaohu
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.01.2020
• Subjects: Betacoronavirus; China - epidemiology; Cities; Coronaviridae; Coronavirus Infections - epidemiology; Coronavirus Infections - transmission; Coronaviruses; COVID-19; Disease transmission; Epidemics; Festivals; Growth rate; Humans; Incidence; Original Paper; Outbreaks; Pandemics; Pneumonia, Viral - epidemiology; Pneumonia, Viral - transmission; Population; Provinces; Regression Analysis; Respiratory diseases; SARS-CoV-2; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Travel; Travel - statistics & numerical data; Travel-Related Illness; Viral diseases; China; United States > US; COVID-19; intracity travel intensity; SARS-CoV-2; population movement
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268820001703

Increased population movements and increased mobility made it possible for severe acute respiratory syndrome coronavirus 2, which is mainly spread by respiratory droplets, to spread faster and more easily. This study tracked and analysed the development of the coronavirus 2019 (COVID-19) outbreak in the top 100 cities that were destinations for people who left Wuhan before the city entered lockdown. Data were collected from the top 100 destination cities for people who travelled from Wuhan before the lockdown, the proportion of people travelling into each city, the intensity of intracity travel and the daily reports of COVID-19. The proportion of the population that travelled from Wuhan to each city from 10 January 2020 to 24 January 2020, was positively correlated with and had a significant linear relationship with the cumulative number of confirmed cases of COVID-19 in each city after 24 January (all P < 0.01). After the State Council launched a multidepartment joint prevention and control effort on 22 January 2020 and compared with data collected on 18 February, the average intracity travel intensity of the aforementioned 100 cities decreased by 60−70% (all P < 0.001). The average intensity of intracity travel on the nth day in these cities during the development of the outbreak was positively related to the growth rate of the number of confirmed COVID-19 cases on the n + 5th day in these cities and had a significant linear relationship (P < 0.01). Higher intensities of population movement were associated with a higher incidence of COVID-19 during the pandemic. Restrictions on population movement can effectively curb the development of an outbreak.