The Coronavirus identified in Wuhan, China, for the first time in late 2019 is a new viral strain that has never previously been identified in humans. It has been called SARS-CoV-2 and the respiratory disease that causes COVID-19. SARS-CoV-2 infection in health professionals has represented and continues to represent a significant criticality both for the risk of spreading the disease and for the organizational aspects that follow.

Currently the gold standard for the non-invasive diagnosis of COVID-19 is the detection of the viral genome by RT-PCR. However, despite the high specificity, this technique has a low sensitivity and can produce false negative samples. Furthermore, detection of the viral genome is indicative of active infection and fails to identify subjects previously exposed to the virus who have passed the infection asymptomatically. Serological tests can detect the presence of anti-SARS-CoV-2 antibodies in blood or serum samples and, depending on the type of antibody detected, identify the subjects in the active phase of the infection and after the resolution of the infection, the whose diagnosis was not made by performing a swab.

We will evaluate the actual spread of the SARS-CoV-2 virus within the hospital personnel of Humanitas through the monitoring of the levels of IgG antibodies. Moreover, viral load will be measured by RT-PCR of nasopharyngeal swabs in the subgroup positive to IgG antibodies. Secondary endpoints are: visualize the trend of the antibody value at 3, 6 and 12 months; correlation between the antibody titer in test positive subjects and the viral load of the nasopharyngeal swab; identification of predictive variables of susceptibility to viral SARS-CoV2 infection.