1. Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA.
2. Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
3. Department of Medicine, Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
4. Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA.
5. Department of Paediatrics and Child Health, College of Medicine, University of Malawi, Chichiri, Blantyre 3, Malawi.
6. Department of Community Health, College of Medicine, University of Malawi, Chichiri, Blantyre 3, Malawi.
7. Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA.
8. Department for International Health, University of Tampere School of Medicine, Tampere 33014, Finland.
9. Department of Nutrition, and Program in International and Community Nutrition, University of California, Davis, Davis, CA 95616, USA.