[1] Univ Cattolica Sacro Cuore, Ist Clin Malattie Infett, I-00168 Rome, Italy
[2] Natl Inst Infect Dis L Spallanzani, Ctr Operat AIDS, Italian Inst Hlth, Rome, Italy
[3] Univ Brescia, Inst Infect & Trop Dis, Brescia, Italy
[4] Spedali Civil Brescia, Dept Infect Dis, I-25125 Brescia, Italy
[5] Osped Civile Pallanza, Dept Infect Dis, Verbania, Italy
[6] Hosp S Martino, Dept Infect Dis, Genoa, Italy
[7] Hosp Vicenza, Vicenza, Italy
[8] Amedeo Di Savoia Hosp, Turin, Italy
[9] Hosp Grosseto, Grosseto, Italy
[10] Univ Milan, Inst Infect & Trop Dis, Milan, Italy
[11] UCL Royal Free & Univ Coll, Sch Med, Royal Free Ctr HIV Me, London, England
[12] UCL Royal Free & Univ Coll, Sch Med, Dept Primary Care & Populat Sci, London, England