1. Tropenklinik Paul-Lechler-Krankenhaus; Tübingen Germany
2. Institute of Public Health; University of Heidelberg; Heidelberg Germany
3. Luang Namtha Provincial Health Department; Luang Namtha Laos
4. Lee Kong Chian School of Medicine; Nanyang Technological University; Singapore
5. Agence Nationale de Recherche sur le VIH et les Hepatites; Phnom Penh Cambodia
6. INSERM; ISPED; Centre INSERM U897-Epidemiologie-Biostatistique; Bordeaux France
7. Epidemiology Unit; Pasteur Institute; Phnom Penh Cambodia