1 Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, MD, USA. Electronic address: jhumphrey@zvitambo.co.zw.
2 Georgia Institute of Technology, School of Civil and Environmental Engineering, Atlanta GA, USA.
3 Environmental Health Group, Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
4 Water, Public Health and Environmental Engineering Group, University of Leeds, Leeds, UK.
5 Civil Engineering, University of Bristol, Bristol, UK.
6 Department of Civil and Environmental Engineering, Makerere University, Kampala, Uganda.
7 School of Engineering, Tufts University, Medford, MA, USA.
8 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge MA, USA.