Data of the eighth Newsletter and of the ISS flash survey
ISS, September 3rd 2021
In Italy in the last 45 days, a predominance of the Delta variant, identified in 88.1% of cases, has been reported to the Integrated Surveillance System.
The data are contained in the eighth ISS Newsletter, "Prevalence and distribution of SARS-CoV-2 variants of interest for public health in Italy".
In fact, from 17 July to 30 August, according to the data in the Newsletter, the number of reports of cases caused by the delta variant (of which the lineage B.1.617.2) in Italy is still higher than the number of reports for all the other monitored variants. New cases of infection caused by the Delta variant have been reported in almost all Italian provinces. The number of cases caused by the Alpha variant and its territorial spread continue decline sharply. Even the cases caused by the Gamma variant (of which the lineage P.1) continue to decrease, with a localized and limited diffusion to some Italian Regions / Autonomous Provinces.
"The capacity to genotype / sequence the positive clinical samples the SARS-CoV-2 virus is high in Italy”, says the President of the ISS, Silvio Brusaferro. “In July, despite the increase in cases reported throughout the country, 11.8% of cases were sequenced / genotyped, more than in June (10.8%). This result has been possible also thanks to the daily work of the laboratories across the Country".
The Delta variant is characterized by a higher transmissibility than the Alpha variant (between 40% and 60%) and is associated with a high risk of infection in partially vaccinated or unvaccinated individuals.
The predominance of the Delta variant was also confirmed by the flash survey of 24 August coordinated by the Istituto Superiore di Sanità- ISS (the Italian National Institute of Health) with the support of the Bruno Kessler Foundation and in collaboration with the Ministry of Health, the Regions and the Autonomous Provinces which estimated a national prevalence of 99.7%. The sample required for the survey was randomly selected by the Regions / Autonomous Provinces from among the positive samples, ensuring geographic coverage and representativeness by age group.
