Beyond the Classroom

Home | Snail fever

Searching for an ecological solution

A dam that brought fresh water to a Senegalese town also brought increased rates of a disease called snail fever. Undergraduate Olivia Cords was part of team investigating a possible ecological solution.

portrait of Oliver CordsFor Stanford undergraduate Olivia Cords, it was the intersection of environmental science and disease that drew her to spend a summer working with postdoctoral scholar Susanne Sokolow in the lab of Giulio De Leo, a professor of biology and senior fellow at the Stanford Woods Institute for the Environment.

That team had been studying an increase in rates of schistosomiasis, or snail fever, in people living near the Diama Dam, which was constructed in 1986 along the Senegal River, in West Africa, as a source of freshwater for irrigation and other uses.

Schistosomiasis is caused by a worm that infects freshwater snails. The dam prevented the snail's primary predator – a type of prawn – from reaching saltwater and completing its lifecycle. Without prawns, the snail population flourished along with the schistosomiasis-causing worm that it harbors.

David Williams, Illinois State University Electron micrograph of an adult male Schistosoma parasite worm

Electron micrograph of an adult male Schistosoma parasite worm. The bar (bottom left) represents a magnification of 500 μm.

Fred A. Lewis, Yung-san Liang, Nithya Raghavan & Matty Knight, The NIH-NIAID Schistosomiasis Resource CenterPhoto of an albino Biomphalaria glabrata

Photo of an albino Biomphalaria glabrata with approximately 5 mm width of the shell

Eventually, the team hopes to find an ecological solution for the disease, such as reintroducing prawns to control the snail population and, the team hopes, reduce rates of new schistosomiasis infections.

Cords specifically focused on finding whether there are other locations where schistosomiasis might have increased as a result of dam building. This work revealed both the highs and lows of carrying out research. "I think you realize how attentive you have to be to details and how sometimes monotonous it is," she said. "But finding something new is exciting."

In addition to being exciting, a discovery could help some of the estimated 220 million people with schistosomiasis, primarily children, fishermen and other people who come into regular contact with water containing infected snails. Those people are at risk of developing diarrhea, anemia, liver or kidney damage, infertility and learning delays. Drugs exist to treat schistosomiasis, but without eliminating the source of infection people remain at risk.

"What I really like is that it has the potential to have so many larger impacts," Cords said. "I realize that is really important to me."

Cords' work was supported through the Mentoring Undergraduates in Interdisciplinary Research program run by the Stanford Woods Institute. Each year participants take a course in interdisciplinary research, then carry out research during the summer. She is currently pursing a co-terminal undergraduate and masters degree in Earth Systems.

"I hadn't considered disease ecology before coming to Stanford," Cords said. "Now it's something that I think I want to do more with. This project gave me ideas about what I want to do next."

View other projects

portrait of Ellie Redding

Digitizing classic fiction

How computer science and an open mind are revealing the genius of dime novel Westerns

portrait of Tim Anderson

3-D printed rocks

Characterizing the subterranean flow of fluids requires repeatable precision. 3-D printed rocks are the solution.

portrait of Sydney Maples and Max Spero

Building virtual worlds

Sydney Maples and Max Spero design virtual reality experiments aimed at altering real-life behaviors.

portrait of Meagan Shinbashi

Memory

Meagan Shinbashi spent odd hours in the lab sussing out when mice learn best

portrait of Olivia Cords

Snail fever

A dam that brought fresh water also brought disease, but an environmental solution might help

portrait of Richie Sapp

Brain research

A drug that helps mice learn more effectively, even later in life, holds promise for human disease

portrait of Annalisa Boslough and Madelyn Boslough

Gold-mining camps

Backpacking deep into the Alaskan wilderness, sisters study long-abandoned gold-mining camps

portrait of Kareem Alston

Hip-hop

Alston delved into an arts organization’s success, with the aim of helping other groups serving youths.

portrait of Daniel Becerra and Charlie Cox

Rocketeers

Pushed the limits of amateur high-altitude exploration by launching a custom-made rocket from a balloon.

portrait of Rukma Sen

Mother monster

Monsters abound in medieval literature, and the same themes of female monstrosity carry on today

portrait of Garima Sharma

Child marriage

Preventing child marriage requires understanding why the practice continues to exist

portrait of Christina Smith

Medieval carvings

Visited English cathedrals to study misericords with musical themes, such as a boar playing a fiddle.