1. Rega Institute for Medical Research and University Hospitals, Katholieke Universiteit Leuven, Leuven, Belgium.
2. Scientific Institute of Public Health, Brussels, Belgium.
3. Universitair Ziekenhuis Gent, Gent, Belgium.
4. Prince Leopold Institute of Tropical Medicine, Antwerp, Belgium.
5. Saint-Pierre University Hospital, Brussels, Belgium.
6. Universitair Ziekenhuis Brussel, Brussels, Belgium.
7. Cliniques Universitaires de Bruxelles, Hôpital Erasme, Brussels, Belgium.
8. Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
9. Liège AIDS Reference Center, University of Liège, Liège, Belgium.