Forecasting Covid-19 Outbreak Progression in Italian Regions: A model based on neural network training from Chinese data

Cosimo Distante; Igor Gadelha Pereira; Luiz Marcos Garcia Goncalves; Prisco Piscitelli; Alessandro Miani

R 0 is an average value, but it can be also computed day by day to monitor the transmission of the infection. Being an average value, it can be skewed by super-spreader events. A super-spreader is an infected individual who infects an unexpectedly large number of people. In Italy this event can be also generated not necessarily by an individual, but from the perturbation of a susceptible population, as it happened in Apulia and Sicily with uncontrolled large group of people coming from outbreak areas. For a "super spreader" individual, such events are not necessarily a bad sign, because they can indicate that fewer people are perpetuating an epidemic. Super-spreaders may also be easier to identify and contain, since their symptoms are likely to be more severe. In short, R 0 is a moving target. Tracking every case and the transmission of a disease is extremely difficult, so the estimation of R 0 is a complex and challengingissue: estimates often change as new data becomes available. In [10] a review of 12 studies on the reproduction number for a time period covered from 1 January 2020 to 7 February 2020was analysed for Covid-19 from China and overseas. The work found that the R 0 estimates ranges from1.4 to 6.49 [12] [11], passing through [14] of 4.08 in mainland China. The review in [10] pointed out a mean of 3.28, a median of 2.79 and interquartile range (IQR) of 1.16, which is considerably higher than the WHO estimate at 1.95. Also in [18] the R 0 for 2019-nCov is reported in the range [1.4, 5.5] . These estimates of R 0 depend on the estimation method used as well as the validity of the underlying assumptions. In a beginning stage, due to a small amount of data and short time onset, these estimates can be biased, and in a longer period converges to the WHO estimate. The initial estimates result in a reproduction number for Covid-19 higher than SARS coronavirus, where this last it is reported to range between 2 and 5.