1. Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
2. Department of Health Policy Planning and Management, Makerere University School of Public Health, Kampala, Uganda
3. Epidemiology and Global Health Unit, Department of Public Health and Clinical Medicine, Umeå University, 901 87 Umeå, Sweden
4. School of Public Health, University of the Western Cape, South Africa