1. Lazio Regional Health Service; Department of Epidemiology; Via di Santa Costanza, 53 Rome Italy 00198
2. Public Health Agency of Lazio Region; Infectious Diseases Unit; Via di Santa Costanza, 53 Rome Italy 00198
3. University of Adelaide; Discipline of Pharmacology; Frome Road Adelaide SA Australia 5005
4. European Monitoring Centre for Drugs and Drug Addiction; Interventions, Best Practice and Scientific Partners; Cais do Sodre' 1249-289 Lisbon Lisbon Portugal