One possible explanation is that the above-mentioned Italian regions represent a central driver of the Italian economy, being the headquarters of several major industries; individuals from other regions and other countries who are involved with such industries may spread the virus elsewhere. Nevertheless, other Italian cities that are overcrowded because of business and tourism, such as Rome, have not experienced the same prevalence and spread of COVID-19. A supposition could be that the northern experience led to severe restrictive measures throughout the country, thereby containing the outbreak.