Epidemiology Student Hopes to Enhance the Lives of Humans and Animals Around the World

by Leigh Ellyn Preston, MPH

Students of Public Health: Voices & Profiles focuses on research projects and other contributions students are making to advance public health.

Leigh Ellyn Preston

Student Voices — In 2017, I participated in a study abroad trip to Quito, Ecuador. Part of the requirements for the trip was to develop a project to complete while living in Ecuador for the five-week period. Drawing on my experience as a schoolteacher, I worked to develop a project that would have a positive impact on the lives and health of children. Together with a team of students and professors at the Universidad San Francisco de Quito (USFQ), I was able to collect information on diarrhea cases in children under age five, and gather information on infrastructural vulnerabilities that could be targeted for primary intervention strategies. We found that diarrhea was diagnosed more frequently in areas near the city center, and that possible primary interventions could include educational campaigns to improve food preparation techniques and hand sanitation, and improved drinking water decontamination processes. The targeted interventions can be used to prevent transmission of pathogens causing diarrhea in children and improve their quality of life.

After working for a year on the research project in Quito, I was approached by the dean of the USFQ School of Public Health about a research collaboration between USFQ, Texas A&M, and the Hospital Oskar-Jandl in the Galapagos Islands. Using data from the local hospital, I developed a research strategy and worked to assemble a team to investigate possible sources of exposure to intestinal parasites. I have been working to collect information on the type of parasitic infection in residents and potential risk factors for exposure to these parasites across the inhabited portions of the island of San Cristobal. Our research team has collected soil, water, and animal fecal samples from various locations throughout the island to analyze for evidence of the parasites commonly isolated in humans. To date, we have identified a slight association between low SES areas and higher prevalence of parasitic infection. Analysis of the environmental samples is ongoing. We hope that by identifying patterns of exposure, we can reduce the burden of parasitic infections and improve quality of life in the Galapagos Islands.

This slideshow requires JavaScript.

In addition to my continuing work in Ecuador, I have also worked to investigate the emergence of flea-borne typhus in central Texas. Most previous research studies have focused on urban areas in south Texas and along the Gulf Coast, and little data is available about the epidemiology of the flea-borne typhus pathogens in rural settings. As a resident of central Texas for the past seven years, this project feels very personal to me. Through partnerships with Baylor Scott & White Health, Baylor College of Medicine, Texas A&M University College of Veterinary Medicine, and Angelo State University, I have collected data on diagnosed human cases of flea-borne typhus to perform a case-series analysis and calculate odds ratios through a case-control study to determine risk factors for diagnosis. I am also in the process of analyzing approximately 450 previously collected blood samples from known and suspected animal reservoirs for the disease in order to better understand the dynamics of disease transmission in Texas. The goal of this investigation is to improve patient care and reduce the time to diagnosis for murine typhus in rural communities, to further the understanding of the transmission cycle of the pathogen, and to improve surveillance efforts of the disease in Texas. To date, I been unable to identify skunks as a reservoir for R. typhi in Texas, but have been able to distinguish several risk factors for diagnosis with flea-borne typhus in communities in central Texas.

My experiences in global health research have made me aware of the importance of involving local researchers to navigate language and cultural barriers that may arise during the investigation. I have learned that culturally appropriate research is imperative to solving international health problems. Investigating the emergence of a disease in novel geographic regions is challenging due to the lack of information surrounding diagnosis and surveillance. Overcoming these challenges is difficult, and I had to rely on the data and expertise of physicians, experienced epidemiologists, and laboratory directors to make the best of the data available. In the future, I hope to work with the federal government and combine my love of animals and my passion for improving the health of children and families through research of the transmission of disease from animals to humans. I hope to build on my experiences with these research projects to develop innovative prevention strategies that will enhance the quality of life for humans and animals around the world.

Leigh Preston

Leigh Ellyn Preston is a doctoral candidate in Epidemiology at Texas A&M University School of Public Health. She holds a Master in Public Health and a Bachelor of Arts in Anthropology from Texas A&M University. Her research interests include one health and zoonotic disease research in domestic and international settings. Follow Leigh on Facebook, Instagram, LinkedIn, and Twitter



Read other students’ stories: