Francesco Barbaro1, Foscarina Della Rocca2, Andrea Padoan3, Aita A3, Vito Cianci2, Daniela Basso3, Annamaria Cattelan1, Claudia Santarossa2, Mario Plebani3, Luigi Dall’Olmo4,5*
Background: Northern Italy was the first area outside China to be involved in the SARS-CoV-2 pandemic. This observational study depicts SARS-CoV-2 prevalence and serological curves among first-line healthcare workers (HCWs) at Padua University Hospital (PdUH), North East Italy.
Method: 344 first-line HCWs underwent a SARS-CoV-2 RNA nasopharyngeal swab with paired IgM and IgG antibody detection for 4 consecutive weeks and after a follow up of 5 months.
Results: Twenty-seven HCWs (7.84%) had positive serology (Abs) with 12 positive swabs during the study period. Two additional HCWs were positive by swab but without Abs. Fourteen cases (4%) had SARS-CoV-2 infection before the beginning of the study. An HCW with autoimmune disease showed false Ab results. 46% of individuals with Abs reported no symptoms. Fever, nasal congestion, diarrhoea and contacts with SARS-CoV-2 individuals correlated to SARS-CoV-2 infection. 96% of Abs+ cases showed persistent positive antibodies 5 months later and none was reinfected.
Discussion: Correct use of PPEs and separate paths for positive/negative patients in the hospital can result in a low percentage of SARS-CoV-2 infections among HCWs. Frequent testing for SARS-CoV-2 is worthwhile, irrespective of HCWs' symptoms.