[1] Univ Roma La Sapienza, Dept Publ Hlth & Infect Dis, I-00185 Rome, Italy
[2] Univ Cassino & Southern Latium, Dept Human Social & Hlth Sci, Cassino, Frosinone, Italy
[3] Univ Cattolica Sacro Cuore, Inst Hyg, Rome, Italy
[4] Univ Palermo, Dept Sci Hlth Promot, Palermo, Italy
[5] Univ Ferrara, Inst Hyg, I-44100 Ferrara, Italy