1 Department of Civil and Environmental Engineering, Tufts University, Medford, MA, USA.
2 Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, CA, USA.
3 Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Blizard Institute, Queen Mary University of London, London, UK.
4 Center of International Policy Research and Evaluation, Mathematica Policy Research, Washington, DC, USA.
5 Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
6 Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya.
7 International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
8 Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe.
9 Department of Nutrition, University of California, Davis, CA, USA.
10 Department of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA.
11 Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA. Electronic address: jhumphrey@zvitambo.co.zw.