The percentage of positive cases in molecular tests reached its peak in Italy, "with an average value of 25% and, in the light of experience, this value should decrease, but the unknown factor remains of a subsequent rise due to the resumption of contacts both for the sales season for the reopening of schools ": this is indicated by the analysis of the mathematician Giovanni Sebastiani, of the Institute for the Applications of Calculation 'M. Picon', of the National Research Council (Cnr).
The curve of the percentage of positive molecular tests has reached its peak (source: Giovanni Sebastiani)
"Today's data confirm the prediction made that we have reached the peak of the percentage of positive molecular tests. With the data updated to January 9, the peak appears to have been reached the day before, but the data for the next few days will make a more accurate localization possible" , Sebastiani observes. "The average value of the percentage at the peak is equal to 25% and is expected to decrease, but it is also expected that the trend will have changed in one to two weeks due to the increase in contacts for activities related to balances and, above all, , for those in relation to today's reopening of schools ".
In this regard, Sebastiani cites the two scientific papers he published with the virologist Giorgio Palù, based on Italian data, and "numerous other scientific studies, also published in international journals": all of them, notes the mathematician, "show that schools contribute significantly to the spread of the Covid-19 epidemic, especially (but not exclusively) in relation to related activities (for example transport) ". Among these, Sebastiani cites a study based on data from 131 countries, which shows that "the reopening of schools leads to an average increase in the Rt reproduction index of about 25%", and another study based on data from 41 States indicate that the closure of schools reduces the value of Rt by about 38% on average.
"The conclusion that schools are safe because during the recent surge in infections in Italy they were closed, recently spread through the media, is wrong as an increase in the incidence of positives started on a given day is induced by a similar spread of the epidemic started one or two weeks earlier ", notes Sebastiani.
"What happens - he adds - is analogous to when we observe the light of the sun, which is relative to its state of about eight and a half minutes earlier".
