1. Infectious Diseases Department, Liège University Hospital, Liège, Belgium
2. Department of Biostatistics, Liège University Hospital, Liège, Belgium
3. Department of Medico-Economic Information, Liège University Hospital, Liège, Belgium
4. AIDS Reference Laboratory, Liège University, Liège, Belgium
5. Department of Clinical Pharmacy, University Hospital of Liège, Liège, Belgium