The evolution of Covid-19 in Italy during the Summer 2020: analysis and interpretation of an unpredicted rest period [article]

Giuseppe De Natale, Lorenzo De Natale, Claudia Troise, Renato Somma, Vito Marchitelli, Antonio Coviello, Karen Holmberg
2020 medRxiv   pre-print
The coronavirus (COVID-19) pandemic was particularly invasive in Italy during the period of March to the end of April 2020 then displayed a significant decrease both in the number of infections and in the seriousness of illness throughout the summer of 2020. In this discussion, we measure the seriousness of the disease by the ratio of Intensive Care Units (ICU) spaces occupied by COVID-19 patients and the number of still Active Cases (AC) each month from April to August 2020. We also use the
more » ... We also use the ratio between the number of Deaths (D) and the number of Active Cases. What clearly emerges, from rigorous statistical analysis, is a progressive decrease of both the ratios, indicating progressive mitigation of the disease. This is particularly evident when comparing March-April with July-August; during the summer period the two ratios have become roughly 18 times lower. We test such sharp decreases against possible bias in counting active cases, and we confirm their statistical significance. We then interpret such evidence in terms of the well-known seasonality of the human immune system and the virus-inactivating effect of stronger UV rays in the summer.
doi:10.1101/2020.08.29.20184127 fatcat:kc3a6xsjmncntazdpulayyoeem