1. Faculty of Public Health, University of Health Sciences, Ministry of Health, Vientiane, Lao PDR
2. School of Public Health and Social Work, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
3. School of Public Health, University of Queensland, Brisbane, Queensland, Australia
4. Institut de Recherche pour le Développement, UMI 233 Trans VIHMI, Inserm U 1175, University of Montpellier, Montpellier, France