Covid, the virus in Italy at least since January 2020

The Sars-CoV-2 virus responsible for the Covid-19 pandemic was in Italy at least since January 2020; also in January it would have arrived in different areas of Europe and the United States, where on 19 January it could have arrived in California and on 2 February in New York: it was a silent beginning, that of the second pandemic of the century, which went unnoticed because there is no it was the widespread test campaign that would have allowed the pandemic to be stemmed in time. This is indicated by the research published in the journal Nature by the group of physicist Alessandro Vespignani, director of the Network Science Institute of Northeastern University in Boston.

Reconstructing the first steps of the pandemic was a decidedly complex job, based on the analysis of thousands of scenarios, among which an algorithm identified the most probable. “We did not simulate a single epidemic, but many possibilities, hundreds of thousands of possible evolutions, and from this basis we calculated the probability of the period in which in Italy the transmission of cases could have occurred autonomously, and no longer by import” Matteo Chinazzi, computational epidemiology expert at Northeastern University and one of the authors of the research, told ANSA.

“We used a model that allowed us to simulate the evolution of the epidemic on a global scale”, explained the researcher referring to data ranging from the distribution of the population to the daily movements of travelers between different countries and cities, to internal mobility within individual countries. Information relating to travel restrictions and flows was then applied to this information.

The result led to possible dates, the result of a probability calculation. The period between 6 and 30 January 2020, for example, is the most probable period in which the transmission of cases within Italy began, however “there is a very low probability, but not zero – observes Chinazzi – that the transmission can start at the end of December 2019 “.

The important thing behind this research is the indication that a widespread and early testing campaign could have changed the course of the pandemic. “Our work – explains the expert – underlines that at the beginning many cases that were developing locally were not visible due to the lack of tests and the too particular criteria used, which for example provided for tests only for those who had been in contact with people who came from China. If the initial criteria had been broader it would have been possible to identify local outbreaks and better control the epidemic “.

There are at least two useful lessons for the future that come from this analysis. The first is in the same approach followed by the Boston researchers, with a model that considers a large number of factors and that could be used with other models, such as those that reconstruct the genetic evolution of viruses and its spread. The second is the ability to carry out tests: “The important thing – observes Chinazzi – is to have the ability to measure the cases in circulation in the field with more general criteria than those that were adopted at the beginning of the pandemic”.


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