Release N°44/2021 In the last 45 days, 88.7% of sequenced swabs tested positive for the Delta variant

 ISS, September 17th  2021

According to the COVID-19 Integrated Surveillance System, in Italy in the last 45 days, 88.7% of sequenced swabs tested positive for the Delta variant (as against 88.1% recorded in the Newsletter of 3 September). The Alpha variant, on the other hand, has almost totally disappeared, being at 0.4% (again in the last 45 days, while it was reported to be 2.3% in the previous Newsletter), This also holds for the Gamma variant (at 0.1% from 0.4%). The data are contained in the ninth ISS Newsletter of the Istituto Superiore di Sanità – ISS (Italian National Institute of Health), "Prevalence and distribution of SARS-CoV-2 variants of public health interest in Italy", and refer to the sequences deposited between 31 July and 13 September 2021 on the I-Co-Gen platform. As expected, these data differ slightly from those of the last flash survey, (the estimated prevalence of the Delta variant was 99.7%) which instead refer to a prevalence survey carried out on a significant sample of cases referring to 24 August.

•    In the last 45 days (31 July - 13 September 2021), the number of cases of SARS-CoV-2 infection that underwent genotyping / sequencing and reported to the COVID-19 Integrated Surveillance System has remained constant: a total of 8,255 compared to 8,300 reported in the previous period (July 17 - August 30 2021).
•    During this reporting period, the number of cases caused by the Delta variant was still higher than the number of reports for all other monitored variants. New cases of infection have been reported in almost all Provinces.
•    The platform for the genomic surveillance of SARS-CoV-2 (I-Co-Gen) variants, developed and coordinated by the ISS, has been in operation since 29 April 2021. The platform allows to collect and analyse the sequences identified on the national territory and to interact with international platforms. The module, dedicated to the analysis and sharing of SARS-CoV-2 sequencing data nationwide, currently counts more than 44,000 sequences.
•    In the last 45 days, among the lineages not monitored by the COVID-19 Integrated Surveillance System, and identified in I-Co-Gen, less than 1% is represented by the VUM (Variant under Monitoring - lineages: B. 1.1.318) and the VOI (Variant of Interest - lineages: B.1.621), the Mu variant, C.37, C.37.1 and the Lambda variant. In particular, of the Mu variant, only one case has been identified in the last 45 days. However, it is essential to continue monitoring these variants to quickly identify any emerging threats.