The Impact of Sanitation on Child Health in Vulnerable Populations: a Multicountry Analysis across Income Levels by Jesse Doyle Contreras A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Epidemiological Science) in the University of Michigan 2020 Doctoral Committee: Professor Joseph N.S. Eisenberg, Chair Associate Professor Veronica Berrocal, University of California, Irvine Associate Professor Rafael Meza Assistant Professor Jon Zelner Jesse D. Contreras [email protected] ORCID iD: 0000-0002-9766-2945 © Jesse D. Contreras 2020 For my brother, Gabriel Contreras, who ensured that I could be here today. ii ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Joe Eisenberg, for your support throughout my master’s and doctoral education. I came to Michigan barely knowing what a Ph.D. was, but your guidance helped me navigate many new worlds without ever feeling lost. Over six years, you have repeatedly helped me find the meaningful story behind my own words, as well as the best local restaurants across three countries, and I am a much better researcher thanks to you. I would like to thank Dr. Rafael Meza for your kindness and for bestowing me with countless lessons, epidemiological and otherwise. Thank you to Dr. Jon Zelner and Dr. Veronica Berrocal for helping me to expand my understanding of statistical methods, which I could not have done without you, and for making this a much better dissertation in the process. I would like to thank the individuals who allowed this research to happen, including all of my co-authors, the Department of Epidemiology administrative team, and the master’s interns who gave key support from the field: Maxwell Salvatore, Grace Christensen, Moira Dickinson, Ruth Thomas, and Marie Kaniecki. I would also like to express my deepest gratitude for the study participants from the Mezquital Valley and the Negev who selflessly gave their time and effort in the name of public health research. iii Thank you to all of my friends from my master’s program, who are too many to name, for helping to make Michigan my home. Thanks to my Ph.D. cohort, particularly Anna Gottschlich for making sure that I balanced school with fun, or maybe the other way around. Thanks to Matthew Vedrin for helping to foster a community of WASH researchers that was instrumental in the development of this dissertation. And I would like to express my gratitude for Hagan Capnerhurst for having so much confidence in me even when I have little, for always reminding me that we are here to serve and to speak for those who are excluded from the conversation, and for making me a better person every day. I could not have started, let alone finished, this process without my family. Thank you to my mother, Ann, whose sacrifices go deeper than I will ever comprehend fully, for your love and for always making me feel that no goal is out of reach. Thank you to my brother, Gabriel, for bearing the weight of the world so I could make it through unscathed. And to my father, Gabriel, who I hope would be proud to see his family name next to three new letters, for making sure that, after all of this school, I still have concrete as a backup. Lastly, I would like to thank the Bill & Melinda Gates Foundation for funding all ten years of my education in public health, for improving the lives of thousands of kids like me, and for providing each of us the opportunity to change the world. iv PREFACE Chapter II has been published in the following journal: Contreras, J.D. and Eisenberg, J.N.S. Does Basic Sanitation Prevent Diarrhea? Contextualizing Recent Intervention Trials through a Historical Lens. International Journal of Environmental Research and Public Health. 2020, 17, 230; doi:10.3390/ijerph17010230. Chapter III has been submitted for publication with the following co-authors: Rob Trangucci, Eunice E. Felix-Arellano, Sandra Rodríguez-Dozal, Christina Siebe, Horacio Riojas-Rodríguez, Rafael Meza, Jon Zelner, and Joseph N.S. Eisenberg. Chapter IV is in the process of submission for publication with the following co- authors: Haneen Shibli, Marisa C. Eisenberg, Ahmad Muhammad, Nadav Davidovitch, Mark Katz, Nihaya Daoud, and Joseph N.S. Eisenberg. v TABLE OF CONTENTS DEDICATION ........................................................................................................................... ii ACKNOWLEDGEMENTS ...................................................................................................... iii PREFACE ...................................................................................................................................v LIST OF TABLES .................................................................................................................viii LIST OF FIGURES ................................................................................................................. ix ABSTRACT ................................................................................................................................x CHAPTER I Introduction .............................................................................................................................. 1 1.1. Brief History of Sanitation ............................................................................................... 1 1.2. Health Effects of Fecal Exposure ..................................................................................... 3 1.3. Sanitation Access Across Income Levels ......................................................................... 5 1.4. Further Challenges in Sanitation .................................................................................... 9 1.5. Dissertation Objectives .................................................................................................. 11 CHAPTER II Does Basic Sanitation Prevent Diarrhea? Contextualizing Recent Intervention Trials Through A Historical Lens ...................................................................................... 16 2.1. Introduction .................................................................................................................... 16 2.2. Methods ........................................................................................................................... 18 2.2.1. History of Literature Reviews ................................................................................. 18 2.2.2. Sub-Group Meta-Regression Analyses ................................................................... 19 2.3. Results ............................................................................................................................. 23 2.3.1. History of Literature Reviews ................................................................................. 24 2.3.2. Sub-Group Meta-Regression Analyses ................................................................... 45 2.4. Discussion ....................................................................................................................... 52 2.4.1. Sewerage Interventions ........................................................................................... 54 2.4.2. Latrine Interventions .............................................................................................. 55 2.4.3. Intervention Coverage ............................................................................................. 59 2.4.4. Study-Initiated vs. Household-Initiated Access ..................................................... 60 2.5. Conclusions ..................................................................................................................... 62 vi CHAPTER III Spatial Risk Of Diarrheal Disease In Association With Household Proximity To Untreated Wastewater Used For Irrigation In The Mezquital Valley, Mexico ....... 79 3.1. Introduction .................................................................................................................... 79 3.2. Methods ........................................................................................................................... 82 3.2.1. Data Source .............................................................................................................. 82 3.2.2. Spatial Data ............................................................................................................. 84 3.2.3. Spatial Analysis ....................................................................................................... 84 3.2.4. Covariate Selection .................................................................................................. 87 3.2.5. Attributable Risk ..................................................................................................... 88 3.3. Results ............................................................................................................................. 90 3.3.1. Household Characteristics ...................................................................................... 90 3.3.2. Spatial Analysis ....................................................................................................... 92 3.3.3. Attributable Risk ..................................................................................................... 92 3.4. Discussion ....................................................................................................................... 94 CHAPTER IV Water And Sanitation Access And Childhood Diarrhea Among The Bedouin Of Southern Israel: