Covid-19 Outbreak Progression in Italian Regions: Approaching the Peak by March 29th

Abstract

AbstractBackgroundItaly and especially the Lombardy region is experiencing a heavy burden of Covid-19 infection. The peak of the epidemics has not yet been reached and it is expected to be delayed in Central and Southern Italian regions compared to Northern ones. We have modeled the Covid-19 outbreak progression in Italian Regions vs. Lombardy.MethodsIn our models, we have estimated the basic reproduction number (R0) -which represents the average number of people that can be infected by a person who has already acquired the infection - both by fitting the exponential growth rate of the infection across a 1-month period and also by using day by day assessment, based on single observations. We used the susceptible–exposed–infected–removed (SEIR) compartment model to predict the spreading of the pandemic in Italy.ResultsThe two methods provide agreements of values, although the first method based on exponential fit should provide a better estimation, being computed on the entire time series. Taking into account the growth rate of the infection across a 1-month period, in Lombardy each infected person has involved other 5 people (4.94 base on data of March 22nd vs. 5.07 based on data of March 19th) compared to a value of R0 = 2.68 reported in the Chinese city of Whuan. According to our model and Piedmont, Veneto, Emilia Romagna, Tuscany and Marche reach an R0 value up to 4. The R0 is 3.7 for Lazio and 3.6 for Campania region, where this latter shows the highest value among the Southern Italian regions, followed by Apulia (3.5), Sicily (3.4), Abruzzo (3.4), Calabria (3.1), Basilicata (2.5) and Molise (2.4). The value of R0 is decreasing in Lombardy and Northern Regions, while it is increasing in Central and Southern Regions.ConclusionThe expected peak of SEIR model can be forecast by the last week of March at national level, and by the first weeks of April in Southern Italian Regions. These kind of models can be useful for adoption of all the possible preventive measures, and to assess the epidemics progression across Southern regions as opposed to the Northern ones.