1. Section of Hygiene, Department of Public Health, Institute of Public Health, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
2. University Clinical-Hospital Center “Dr. Dragisa Misovic-Dedinje”, Milana Tepica 1, 11000 Belgrade, Serbia
3. Department of Public Health and Infectious Diseases, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
4. IRCCS San Raffaele Pisana, Via della Pisana 235, 00163 Rome, Italy