1. Médecins Sans Frontières, 78 rue de Lausanne, 1211 Geneva, Switzerland.
2. Department of Clinical Microbiology, University College Hospital, London, England.
3. Faculty of Health Sciences, University of Ottawa, Ottawa, Canada.
4. Department of Medicine, Imperial College London, London, England.
5. Center of Excellence for Research in AIDS, University of Malaya, Kuala Lumpur, Malaysia.
6. Manson Unit, Médecins Sans Frontières, London, England.