The Impacts of Water, Sanitation, Hygiene, and Seasonal Drivers on Diarrheal Disease Dynamics in Laikipia, Kenya

Abstract

Diarrheal disease is the second global leading cause of death among children under five years old, taking the lives of 760,000 children every year. The majority of the disease mortality and morbidity falls disproportionately on the developing world, and 32,000 of these yearly childhood diarrheal disease deaths occur in Kenya. Nearly 88 percent of global diarrheal deaths are attributable to unsafe water, inadequate sanitation, and poor hygiene. Water, sanitation, and hygiene are collectively referred to as WASH. This thesis examined the interactions between diarrheal diseases, seasonal variations, and WASH access and behavior of Maasai pastoralist populations in Northern Kenya. These populations live in close proximity to livestock, have little access to clean water and sanitary facilities, and practice poor hygiene behaviors, which makes them an ideal case study for examining WASH access and behavior. This thesis was divided into four parts. First, we identified risk factors for diarrhea and hygiene behaviors in this population through a case-control study. We found that WASH access and behavior do not significantly affect the odds of diarrhea. Our results show that children who attend school and have herding responsibilities have higher odds of washing their hands. Second, using GPS coordinates, we created a map of the sanitation infrastructure and WASH facilities of the study site, which demonstrates the limited access to water and sanitary facilities of the study population. Next, we collected and tested point of source and point of use water samples for fecal contamination. We show that unimproved water sources contain more fecal contamination than improved water sources. We also found that as a result of water purification methods, point of use water contains less fecal contamination than point of source water. Finally, the impacts of seasonal drivers on diarrheal diseases were evaluated. The diseases examined increased with extremely low and extremely high rainfall, increased with higher daily temperature differences, and decreased with increased vegetation. These relationships occurred with different time lags associated with each seasonal driver and disease. The changes of these seasonal drivers influence human behavior, as well as pathogen transmission, both of which may account for the seasonality of diarrheal diseases.