1. Department of HIV, World Health Organization, Geneva, Switzerland
2. Social and Behavioral Interventions Program, Department of International Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
3. Division of Global and Community Health, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
4. Independent Clinical Epidemiologist, Cape Town, South Africa
5. Department of Essential Medicines and Health Products, World Health Organization, Geneva, Switzerland