1. Nutrition and HIV/AIDS Policy, Policy, Strategy and Programme Support Division, World Food Programme, Rome 00148, Italy
2. Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA 02111
3. Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21025
4. Department of Ophthalmology, Johns Hopkins University, Baltimore, MD 21025
5. SIGHT AND LIFE, Basel 4002, Switzerland