1. Heidelberg Institute of Global Health, Ruprecht-Karls Universität Heidelberg, Heidelberg, Germany
2. Department of Epidemiology and Biostatistics and Department of Health, Research Institute for Tropical Medicine, Muntinlupa, Philippines
3. School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
4. International Health Department, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA