1. Local Health Unit 1 of Umbria, Prevention Department, Epidemiology Service, 06126 Perugia, Italy
2. Department of Biomedical Sciences and Public Health, Section of Hygiene, Preventive Medicine and Public Health, Polytechnic University of the Marche Region, 60121 Ancona, Italy
3. Department of Medicine and Surgery, University of Perugia, 06123 Perugia, Italy