Unraveling the role of water hyacinth in modulating schistosomiasis to facilitate scaling a proven disease control intervention - schistosomiasis is a debilitating parasitic disease that imposes major…

The Department of Health and Human Services National Institutes of Health Fogarty International Center awarded the University of Notre Dame DU Lac $189,000 on September 1, 2026, under the International Research and Research Training program (CFDA 93.989) to identify ecological and behavioral mechanisms driving the relationship between water hyacinth density and schistosomiasis mansoni prevalence in Lake Victoria.

The project will resolve a critical scientific question before an aquatic vegetation removal (AVR) intervention developed and proven in Senegal can be safely scaled to East Africa. Preliminary evidence suggests a non-linear, hump-shaped relationship between water hyacinth coverage and S. mansoni infection rates in Kenya—a pattern potentially driven by water hyacinth simultaneously increasing snail habitat and parasite density while reducing human water contact at high coverage levels. Removing hyacinth without understanding these mechanisms risks unintentionally increasing disease transmission. Kenya provides a natural laboratory unavailable in the United States because active schistosomiasis transmission occurs across natural gradients of water hyacinth, enabling ecological and behavioral mechanisms to be studied under real-world conditions.

The award supports research performed at Notre Dame's campus in Notre Dame, Indiana, with a period of performance from September 1, 2026, through June 30, 2028. The assistance type is a Project Grant.

Unraveling the role of water hyacinth in modulating schistosomiasis to facilitate scaling a proven disease control intervention - schistosomiasis is a debilitating parasitic disease that imposes major health and economic burdens worldwide and remains relevant to american health through international travel, military deployment, immigration, and global infectious disease preparedness. In the lake victoria basin, millions are infected with schistosoma mansoni, and reinfection remains high despite annual mass drug administration. Our team previously developed an innovative intervention in senegal: aquatic vegetation removal (AVR) to reduce snail habitat and interrupt parasite transmission. In randomized controlled trials, AVR significantly reduced schistosoma infections while the harvested vegetation was converted into compost, livestock feed, and biodigester fuel, generating economic returns that exceeded intervention costs. Before AVR can be expanded to east africa, an important scientific question must be resolved. The dominant invasive aquatic plant in lake victoria is water hyacinth (pontederia crassipes), which differs ecologically from vegetation in senegal. Preliminary analyses suggest a hump-shaped relationship between water hyacinth density and S. Mansoni prevalence. This pattern may result from water hyacinth simultaneously increasing snail habitat and parasite density while reducing human water contact at high coverage levels. Removing hyacinth without understanding these mechanisms could unintentionally increase disease risk. Kenya provides a unique natural laboratory unavailable in the united states because active schistosomiasis transmission occurs across natural gradients of water hyacinth, allowing ecological and behavioral mechanisms to be studied under real-world conditions. The goal of this project is to identify the ecological and behavioral mechanisms driving this non-linear pattern to ensure that AVR can be safely adapted to east africa. We will (1) quantify how water hyacinth density affects snail and cercarial densities using field surveys, cercarial shedding assays, and remote sensing, and (2) determine how water hyacinth influences human water-contact behavior through structured observations and household surveys. By identifying generalizable ecological and behavioral mechanisms governing environmentally mediated transmission, this project will provide the scientific foundation for adapting AVR to new settings and designing future intervention trials. The resulting knowledge will be broadly applicable to environmentally mediated parasitic diseases and will inform prevention strategies relevant to americans through travel medicine, military deployment, immigration, and global infectious disease preparedness. Because these mechanisms are expected to be reproducible across endemic settings, this work will establish principles that can guide future implementation and evaluation of environmental disease-control interventions.