1. 1School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia;
2. 2School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia;
3. 3Instituto de Microbiologia, Universidad San Francisco de Quito, Quito, Ecuador;
4. 4Rollins School of Public Health, Emory University, Atlanta, Georgia;
5. 5Centro de Biomedicina, Universidad Central del Ecuador, Quito, Ecuador;
6. 6School of Public Health, University of Washington, Seattle, Washington