Origin, Genetic Variation and Molecular Epidemiology of SARS-CoV-2 Strains Circulating in Sardinia (Italy) during the First and Second COVID-19 Epidemic Waves.

Understanding how geography and human mobility shape the patterns and spread of infectious diseases such as COVID-19 is key to control future epidemics. An interesting example is provided by the second wave of the COVID-19 epidemic in Europe, which was facilitated by the intense movement of tourists around the Mediterranean coast in summer 2020. The Italian island of Sardinia is a major tourist destination and is widely believed to be the origin of the second Italian wave. In this study, we characterize the genetic variation among SARS-CoV-2 strains circulating in northern Sardinia during the first and second Italian waves using both Illumina and Oxford Nanopore Technologies Next Generation Sequencing methods. Most viruses were placed into a single clade, implying that despite substantial virus inflow, most outbreaks did not spread widely. The second epidemic wave on the island was actually driven by local transmission of a single B.1.177 subclade. Phylogeographic analyses further suggest that those viral strains circulating on the island were not a relevant source for the second epidemic wave in Italy. This result, however, does not rule out the possibility of intense mixing and transmission of the virus among tourists as a major contributor to the second Italian wave.

Serological surveillance of Leptospirosis in Italy: two­year national data (2010­2011).

Nowadays, leptospirosis is a re­emerging widespread infectious disease often underestimate worldwide. The National Reference Centre for Leptospirosis (NRCL), at the Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Brescia (Italy), with the cooperation of all the other Istituti Zooprofilattici Sperimentali (IIZZSS), evaluated the distribution of such important zoonosis in Italy. Serological data obtained between 2010­2011 by each laboratory were collected by the NRCL and discussed. Serum samples collected from 43,935 animal specimens were analysed by the Microscopic Agglutination Test (MAT), using a panel of 8 serogroups as antigens (Australis, Ballum, Canicola, Grippotyphosa, Icterohaemorrhagiae, Pomona, Sejroe, Tarassovi). A MAT cut­off of 1:100 was used to identify the serological positivities, 6,279 sera showed positive titers. Bovine (46.9%), swine (27.5%), ovine and goat (7.4%), dog (6.9%), and wild boar (4.5%) samples were delivered to the Laboratories more frequently than equine and other species sera. Data analysis showed that the most common serogroups in Italy are: Australis present in dogs, wild boars, horses, hares, swine, foxes, and rodents; Sejroe detected in cattle, sheep, goats, and buffaloes; Icterohaemorrhagiae present in dogs, goats, and foxes; Pomona detected in swine, cattle, and wild species; Grippotyphosa reported in hares.

Small ruminant lentivirus genotype E is widespread in Sarda goat.

The highly divergent SRLV genotype E has recently been characterized in Italy as a low pathogenic caprine lentivirus in the Roccaverano breed. The availability of a genotype specific diagnostic test based on a comparative assay, using a combination of genotype specific recombinant antigens allows a wide serosurvey in other goat populations. The island of Sardinia still has the highest small ruminant population of any Italian region and crossbreeding has been limited to goats, mainly with the Maltese breed. A serological survey was carried out on sheep flocks and goat herds, using individual sera as well as a bulk milk-adapted procedure. Genotype E was identified in more than 50% of goat herds and none of the sheep flocks thus supporting the idea that this genotype is specifically associated with the goat species. The full-length proviral sequence of a Sardinian isolate revealed and confirmed the deletion of dUTPase subunit and the absence of both vpr gene and the 71bp repeat of the LTR. Genetic similarity of this isolate with the prototype strain Roccaverano was not more than 84%, supporting the designation of two subtypes within genotype E. Nevertheless, in vitro properties of the Sardinian strain were different from those of the Roccaverano strain in terms of ability to infect synovial membrane and produce syncitia. Remarkable differences in the HV1 and HV2 of the env gene were recorded, with the Sardinian isolate displaying sequence motif more similar to arthritic strains. Data presented suggest diffusion of genotype E is wider than previously thought.