[1] Natl Inst Infect Dis, I-00149 Rome, Italy
[2] Univ Cattolica Sacro Cuore, Inst Infect Dis, Rome, Italy
[3] Univ Brescia, Inst Infect & Trop Dis, Brescia, Italy
[4] San Salvatore Hosp, Dept Infect Dis, Pesaro, Italy
[5] Ist Ospitalieri, Dept Infect Dis, Cremona, Italy
[6] Busto Arsizio Hosp, Dept Infect Dis, Busto Arsizio, Italy
[7] Circolo Hosp, Dept Infect Dis, Varese, Italy
[8] Cuggiono Hosp, Dept Infect Dis, Cuggiono, Italy
[9] Univ Milan, Inst Infect & Trop Dis, Milan, Italy
[10] UCL Royal Free & Univ Coll Med Sch, Dept Primary Care & Populat Sci, London, England