1. a Department of Infectious Diseases , Catholic University , Rome
2. b Department of Infectious Diseases , S. Anna Hospital , Como
3. c Department of Infectious Diseases , Busto Arsizio Hospital , Busto Arsizio
4. d II Department of Infectious Diseases , L. Sacco Hospital , Milan
5. e Department of Infectious Diseases , S. Maria Nuova Hospital , Reggio Emilia
6. f IRCCS 'L. Spallanzani' , Rome
7. g HIV Screening Clinic , Verona
8. h Department of Health Policy and Management Bloomberg School of Public Health , Johns Hopkins University , Baltimore