[Retrospective study on a CoViD-19 outbreak that developed in February during a dinner in the municipality of Capannori (Lucca).]

Orsucci, Giulia; Rocchi, Rachele; Menconi, Arianna; Salvoni, Franco Antonio

The first cases of SARS-CoV-2 were reported in Wuhan, China, in December 2019. In January the disease spread rapidly to other regions and beyond Chinese borders until it reached Italy where, on February 21, the first case of non-imported contagion was found. On the same date, as the commercial activities were still regularly open, the dinner, which saw as protagonists the participants of this retrospective study, took place. Of the 49 people attending the event, 47 joined the study. The participants of this study were all males, with an average age of 57 years old, all asymptomatic during the dinner. The participants voluntarily underwent serological or swab tests for SARS-CoV-2 and answered questions from our telephone interview. From the data obtained it emerges that 26 people (55.3%), after the dinner, developed one or more symptoms. The most frequently encountered symptom was fever, present in 76.9% of the symptomatic. 26 people were positive on the diagnostic tests (55.3% of the total examined), 24 of them were symptomatic. The conceivable R0 (the basic reproduction number) is higher than the one present in the literature (7.7 vs 3.8), this is probably due to the conditions in which the dinner took place (not ventilated environment, absence of safety distances, absence of personal protective equipment).