On Christmas day, the cases of Omicron in Italy amounted to about 45% of the total of the approximately 54,762 cases of SarsCoV2 that were registered: this is indicated by the calculations of physicist Roberto Battiston, of the University of Trento and coordinator of the Observatory of epidemiological data in collaboration with the National Agency for Regional Health Services (Agenas). The data relating to Christmas day and the previous day are currently the most reliable to make these estimates, pending normal test activity after the holidays.
"In Italy, Omicron made itself felt in the particular moment of the holidays. Its massive growth was expected, but - observes Battiston - it is happening without knowing enough, even if the heavy effects are clearly visible, such as the large number of infected that add to Delta's contribution, swabs not found and queues in front of pharmacies. The numbers of the epidemic are growing fast, but the sequencing data is scarce and very slow compared to the speed with which the virus moves " . However, the statistical analysis of the data provided by the Civil Protection allows us to quickly obtain useful information on the trend of the Omicron epidemic, subtracting from the recorded data the expected trend of Delta cases, regularly monitored in the last two months.
"From the regular trend of the Delta it was possible to estimate a weekly peak of about 30,000 cases at Christmas, which actually occurred. Without this contribution, we obtain the contribution due to Omicron, a variant that clearly shows its presence, at of rapid growth of RT and statistical data, already in more than 50% of the 107 Italian provinces ".
Omicron almost absent in the yellow regions
The data of the Civil Protection indicate that the Omicron variant in the yellow regions is not yet clearly developing as it happens in almost all the white regions, where the new variant is taking over. This is indicated by the analyzes of the physicist Roberto Battiston, of the University of Trento and coordinator of the Observatory of epidemiological data in collaboration with the National Agency for Regional Health Services (Agenas).
"The seven yellow regions show, for now, an almost absence of Omicron's contribution - says Battiston to ANSA - In areas where the Delta variant had reached very high values, such as Alto Adige and Friuli Venezia Giulia, the infected are now they are going down and Rt is back to 1: Delta is therefore going back and the growth of Omicron is not yet seen, at least at a statistical level ".
In Veneto, Marche and Liguria there is no decrease in cases, "but these regions are also dominated by the Delta: the Omicron variant, when it is significantly present, shows a characteristic very rapid rise in Rt and in the number of infected, which, at the moment, it does not appear in the data, observes the physicist. "It gives", he notes, "an indication that the type of controls in place in the yellow zones, partly due to national regulations, partly to the initiative of the governors, they are delaying the explosion of Omicron cases, which is rapidly gaining the upper hand in almost all white regions. "
The exceptions are Sardinia, which usually shows delays in following the continental dynamics, and Emilia Romagna, which, despite its proximity to Lombardy, Piedmont and Tuscany, white regions very affected by Omicron "does not yet show a clear presence of the Omicron, a fact that deserves further study. Just think of the case of the province of Piacenza, with a weekly incidence on 100,000 inhabitants of 233 and Rt stable at 1.43, 40 km from Lodi, which has a weekly impact on 100,000 inhabitants of 844 and Rt which reached 2.39 in just a few days ".
Even in many provinces, Battiston continues, an anomalous growth can be observed that can be associated with the Omicron: on December 24th those showing this growth were 20, another 29 were added on Christmas Day: overall we are now exceeding half of the Italian provinces. Considering that the figures for December 26 are necessarily very partial given the low test activity, a strong further growth in these figures is likely in the coming days.
For Battiston "it is important to understand why the yellow regions show, at least in the short term, a greater resistance to the invasion of Omicron: this can be useful to understand what to do in the short term also in other regions, what are the limitations, such as outdoor masks and the containment of the number of people in restaurants, museums and stadiums, which are more effective or which should be strengthened at a national level ".
According to the physicist, we should act "on the path of what has been done in Germany, which with the measures that have limited the movement of the unvaccinated compared to the vaccinated and which provide for the systematic implementation of repeated tests for school students, in less than a month has dropped drastically towards lower values than those of Italy, Spain and France. Germany has not only managed to bend and extinguish a very strong peak of Delta cases but at the same time it is the only large European nation where no they still see the effects of Omicron's presence. "
