Why Are There These Differences Among Regions?
Substantial differences occur throughout Italy, with the north of the country, predominantly Lombardy, exhibiting the highest rates of spread and mortality.1. 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.
2. Climate conditions may also be relevant to the differences reported among Italian regions. Higher temperature and humidity may block virus diffusion and reduce its persistence in the air and on the objects.6 This explanation has been given to the unequal distribution of the contagion among the continents. In Italy, however, differences in climate among regions are less than what exists between Italy and other parts of the world such as China.
3. More recently, there is increasing attention on the possible role of air pollution in virus diffusion. The correlation between the air pollution index and increased fatality was previously hypothesized for the severe acute respiratory syndrome caused by a virus member of the Coronaviridae family; subsequent evidence supported this hypothesis for the severe acute respiratory syndrome. In particular, atmospheric particulate seems to act as a carrier of the virus, facilitating its diffusion and dissemination and allowing its survival in active form for hours and even days. Indeed, air pollution imposes an increased vulnerability of the population to respiratory syndromes, even in the absence of microbial causative agents. A recently published position paper of the Italian Society of Environmental Medicine in collaboration with 2 Italian universities compared COVID-19 case distribution (updated to March 3) and air pollution levels in the past 20 days. Interestingly, northern Italy had both the most polluted area and the highest number of cases of COVID-19, thereby supporting the possibility that the degree of air pollution may contribute to regional differences in cases of COVID-19.7
In sum, there is no single explanation that accounts for the severity and catastrophic consequences of the COVID-19 outbreak in Italy. Intense and sustained effort is needed to optimize strategies that prevent the spread of infection and to devise targeted therapies for the disease. In the meantime, severe restrictive measures and strict social distancing are crucial to contain the contagion among the population. Hospitals should be provided with appropriate personal protective equipment, ventilators, and further intensive care unit equipment to preserve the medical staff and to optimize care for all patients.