[1] Univ Roma La Sapienza, Dept Med Pathophysiol, Rome, Italy
[2] Univ Roma La Sapienza, Dept Infect Dis, Rome, Italy
[3] Assoc Lombarda Tossicodipendenze, Melzo, Italy
[4] Gen Hosp, Div Infect Dis, Foggia, Italy
[5] Policlin San Matteo, Dept Infect & Parasit Dis, I-27100 Pavia, Italy