The Covid-19 epidemic in Italy is in an exponential phase of increase, with a doubling time of about 5 days, lower than that recorded in October, probably due to the circulation of variants.
This is what emerges from the analyzes carried out, at national level, by the mathematician Giovanni Sebastiani, of the Institute for the Applications of Calculation 'Mauro Picone' of the National Research Council (Cnr-Iac), relating to the curve of the percentage of positives with respect to molecular swabs and that of the number of patients who enter intensive care units every day.
"The percentage of positives compared to molecular swabs quantitatively describes the circulation of the SarsCov2 virus but - observes Sebastiani - unfortunately in our country it undergoes an exponential increase in recent weeks, and every 5 days it doubles its increase. With the data next week we will have a more accurate estimate of the doubling time. "
The situation, continues the expert, "is identical for the curve of intensive care admissions, which instead quantifies the pressure that the circulation of the virus exerts on healthcare structures. It should be noted that, in the same initial exponential phase of the second wave , in the first three weeks of October 2020, the doubling time was about 7 days. The fact that the doubling time is now lower than in October is compatible with the greater diffusivity of some of the variants of the virus currently circulating in our Country".
With regard to deaths, the mathematician notes that "from the analysis of the percentage of the weekly variation in incidence, a return to the growth of the average curve is expected during the next week".
For Sebastiani "it should be emphasized that we currently have an average value of about 300 deaths per day, as if we had an earthquake in L'Aquila or Amatrice every day and we absolutely must not get used to this" and points out that "it is important to vaccinate as much as possible the fragile categories to directly reduce mortality. It would also be desirable for the under 65s to be vaccinated, 7 days a week, 24 hours a day, to reduce the circulation of the virus, also contributing, indirectly, to reducing mortality ".