Stanford students undertake field research in Senegal to combat schistosomiasis

With daytime highs reaching 107F this summer, it never got cold enough in Saint-Louis, Senegal, for Chris LeBoa and Sofia Ali to unpack the winter jackets they brought from home. LeBoa and Ali, both Stanford seniors majoring in human biology, spent the summer working on a project researching the ecology of schistosomiasis transmission along the Senegal River.

Schistosomiasis, a disease caused by a parasitic worm transmitted by freshwater snails, affects 250 million people worldwide. In the Senegal River Valley, over 80 percent of the population is affected. The completion of the Diama Dam on the Senegal River in the 1980s was a large factor in a vast expansion of agriculture in the region, but the dam also impacted the migratory patterns of river prawns that eat snail hosts of schistosomiasis. Left untreated, the disease can lead to liver damage, kidney failure, infertility, or bladder cancer.

LeBoa and Ali were in Senegal as Center Summer Undergraduate Field Research Assistants on a project led by Stanford biologist Giulio De Leo. De Leo has been working for several years on assessing the feasibility and scalability of interventions that address the environmental source of infection. LeBoa and Ali assisted with the collection of snail hosts and conducted household surveys in order to understand the details of agricultural livelihoods and human-environment interactions in mediating disease risk. Their field research in the Senegal River Valley made each of them eligible for a Cardinal Quarter summer full-time public service opportunity.

LeBoa, a co-term in epidemiology, has worked for the De Leo lab since 2016. Over the summer, he finally met the research collaborators in Senegal with whom he had been communicating for two years. In the field, he worked closely with Isabel Jones, a 2017 Autumn Graduate Student Research Funding Recipient from the Center.

Ali has worked as a research assistant with the Global Child Health Program and her interest in global health led her to apply for this opportunity. In Senegal, Ali’s work was supervised by graduate student Andrea Lund, who led the field work.

Both LeBoa and Ali lived in Saint-Louis, four hours north of Senegal’s capital city of Dakar, where the office of the research group’s community partner, Espoir Pour La Santé (EPLS), is located.

When they returned to Stanford, LeBoa and Ali shared their experiences from the field.

What was the purpose of the field research you worked on and what was your involvement with it?

LeBoa: My work is part of a 5-year project on using environmentally-based control mechanisms to eliminate schistosomiasis from the Senegal River. We have been reintroducing prawns that kill the snails, which are secondary hosts of this Schistosoma parasite.

My work specifically focuses on using DNA collected from water to detect the worms in different parts of the river. This summer we also did deep water sampling of the river and found that schistosomes are also prevalent a lot farther from the water access points than previously thought.

Ali: I worked with the supervisor team to review surveys completed by the enumerators. The process allowed for data quality assurance to be performed in the field for all 16 villages, ensuring a comprehensive data set. After transitioning to the river villages, I conducted structured water observations at all of the water points in each village. Andrea and I created a form to track different activities at these waterpoints. Each day, we visited water points for one hour, tracked the sex and age of individuals at the water point, and noted the activity they were engaging in and the extent/duration of their water contact. I am currently creating an electronic data set using the information from the forms we completed.

Can you describe a typical day during your time in Senegal?

LeBoa: Early in the morning we rode in trucks to one of the rivers nearby. We sorted vegetation for snails and took boats to collect more vegetation and take water measurements. In the evenings, we shed the snails and looked at them under microscopes to see parasites. Afterward, we would have dinner, sit on the porch with Samba, the security guard, using Google Translate to have conversations between English and Portuguese.

The streets in Saint-Louis were always bustling. In the morning it was people going to mosque, then around 7am the baguette shops opened. Throughout the day shepherds pushed their flocks down the streets. In the afternoon soccer games started on every block. Once it was dark, people sat on their porches or on mats in the street and drank tea. I loved walking and practicing Wolof with the people I met.

Ali: I tried to go to Senegal with an open mind and few expectations. I knew that Senegal was a predominantly Muslim country, but it wasn’t until I arrived that I realized how deeply religion can shape a nation. As a Muslim, it was truly refreshing to see billboards wishing “Eid Mubarak,” hear the azan coming from the mosque in my neighborhood, and watch as people dropped everything and prayed on sidewalks when the time came.

How did your research experience this summer influence your future goals?

LeBoa: This experience put a lot of the lab work I had been doing into perspective. For processes that we had optimized in the lab, I had to quickly adapt in the field. For example, when the pump we were using in the lab this summer broke in Senegal, we had to convert a bike pump until we could buy a new pump.

The project also affirmed my interest in pursuing a career in disease ecology. It showed me how there are still so many unanswered questions in the field and a lot of ways that research can still be used to help improve the lives of many people both at home and globally.

Ali: This experience was incredibly valuable to the strengthening of my academic interests, particularly in the field of epidemiology, and to the development of my career goals. The time I spent in Senegal reified the complex interplay of social and environmental factors that determine schistosomiasis risk, especially in poverty-stricken areas. This experience continues to motivate me to pursue a career as a physician and researcher committed to a more holistic understanding of health and disease. 

How was the local cuisine?

LeBoa: The main parts of my diet in Senegal were mangos and baguettes.  We would buy baguettes from Kimba across the street every morning and then pack cheese with them for lunch in the field. Sometimes we would get offered thieboudienne from families in the villages or from our Senegalese collaborators. This is the national Senegalese dish and is rice with vegetables and fish.

The best thieboudienne I had was with a man who invited me to the naming ceremony of his son. After the ceremony we shared giant platters of thieboudienne with a group of byfal drummers. Since my French was shakey the dad invited his friend who spoke Spanish to come and translate so that we could all talk.

Ali: In the field, the entire team ate lunch together, with eight or so people sitting around each massive bowl of delicious thieboudienne. For dinners, I often ate at restaurants called dibiteries, which served a spin on the traditional hamburger (the “Senegalese burger”) with fried egg, French fries, and lots and lots of ketchup included inside the burger.

What is the biggest challenge and the greatest benefit of doing field work in a developing country?

LeBoa: The logistics of field work and the messiness of data collection are some of the biggest challenges of doing field work anywhere. There are so many variables to any disease ecology work and it is hard to separate them all out to get scientifically rigorous and meaningful results. It is also hard to work through language barriers. However, doing research on the ground is the only way to truly understand a situation and its complexities.

Ali: One of the biggest challenges is the need to be constantly open to change. We ran into hurdles in the field like unexpected weather and a broken-down van. In these situations, it was incredibly important to be prepared to change plans at a moment’s notice. Field work provides valuable perspective, which is unparalleled by any other research experience.

I learned to always ask questions. In a new country, there is so much to learn from locals and researchers, who are such great sources of information about culture, history, and day-to-day living. I found that being curious was always admired, and I witnessed the importance of including locals and community partners in any type of public health project. I can’t imagine how this project would have run without the support of EPLS, which had established relationships with the chiefs of the survey villages, and the various Senegalese members of the research team (enumerators, translator, team manager).

Can you share an encounter you had with someone that has made a lasting impression on you?

LeBoa: A lot of days after work I would go hang out with a friend I met named Muhammad Beye. He is in his 60’s and works out of a small, smoky concrete room. He didn’t speak much English and my French is spotty at best, but we would talk/draw in a mixture of English, Spanish, French and Wolof for hours about a wide variety of subjects – politics, history, religion, basics of Wolof. Every night we would also share tea or I would come with some mangos I picked up on the way.

Ali: We worked with a dynamic team of eight Senegalese data collectors, and I often accompanied them when they went from household to household filling out surveys. One day, I decided to join Amadou. As we were walking to the first concession, he told me that he was really grateful to have the opportunity to be a data collector because he had never visited the countryside before; he was from Dakar. In other words, the experience of traveling from village to village was as new to him as it was to me. At first, I was surprised, but I quickly questioned my reaction, seeing how easily I had assumed that the Senegal I saw through my field work was somehow representative of the country as a whole.

Please note that prior to May 2019, the Stanford King Center on Global Development was known as the Stanford Center on Global Poverty and Development.
Also note that prior to January 2024, the King Center’s Undergraduate Research Fellow Program was known as the Undergraduate Research Assistant Program.