1. Unit of Medical Statistic and Moelcular Epidemiology, University Campus Bio-Medico, Rome, Italy.
2. HIV Databases, T-6, Los Alamos National Laboratory, Los Alamos, New Mexico.
3. Unit of Virology, University Campus Bio-Medico, Rome, Italy.
4. Unit of Clinical Laboratory Science, University Campus Bio-Medico, Rome, Italy.
5. Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
6. Migrant Health Research Organisation (Mi-HeRO)—Centro di Ricerca sulla Salute delle Popolazioni Mobili e Globale, Rome, Italy.