1. Department of Global Health, University of Washington, Seattle, Washington, USA.
2. John Snow, Inc., Lusaka, Zambia.
3. Department of General Internal Medicine, Massachusetts General Hospital Global Health, Boston, Massachusetts, USA.
4. Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
5. Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, California, USA.
6. Department of Ophthalmology, University of California, San Francisco, San Francisco, California, USA.
7. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California, USA.
8. Africa Health Research Institute (AHRI), Somkhele and Durban, South Africa.
9. Heidelberg Institute of Public Health (HIGH), University of Heidelberg, Heidelberg, Germany.