Emergence and biological control of schistosomiasis

University Of California Santa Barbara, Santa Barbara CA

Investigators

Linked publications & trials

Abstract

DESCRIPTION (provided by applicant): Many newly emerging diseases have resulted from large-scale ecological changes that increase human exposure to animal reservoirs and environmental sources of disease. Approximately 60-80% of the infectious agents that cause disease in humans are shared with animal hosts. Veterinarians are excellent candidates to study these emerging diseases, but training programs specifically tailored to the integration of veterinary medicine and basic biological research to study the environmental and animal components of infectious disease emergence are scarce. The proposed training will provide a multidisciplinary program in infectious disease which aims to develop modern interdisciplinary approaches for public health research by combining fundamentals in biological science, experimental design, epidemiology, disease modeling, and global public health principles. The model system chosen for the research component, schistosomiasis in western Africa, is an ideal example of an emerging infectious disease with clear ecological links. Schistosomiasis is caused by infection with an indirectly-transmitted helminth parasite which requires a snail intermediate host to complete its lifecycle. Compelling evidence has linked schistosomiasis emergence in the Senegal River basin with snail population expansion after the building of the Diama Dam. To date, schistosomiasis remains a major public health problem in Senegal despite chemotherapy and medical management campaigns. Novel transmission control strategies are needed. Through field research, controlled experiments, and mathematical modeling, this project examines: (1) whether the disruption of snail predators in the Senegal River basin after Dam construction substantially contributed to disease emergence for schistosomiasis, and (2) whether snail predator reintroduction via aquaculture is a viable long-term transmission control strategy. Schistosomiasis is currently among the most prevalent human parasitic infections worldwide, and the lower Senegal River basin harbors some of the most intense transmission foci for human schistosomiasis in the world. The proposed project explores a control strategy that may sustainably reduce schistosomiasis transmission to humans and offer economic benefits to poor local communities through aquaculture. RELEVANCE: For schistosomiasis control, chemotherapy offers an effective short term solution to decrease morbidity, but re-infection commonly occurs. Innovative transmission controls are needed for this emerging disease. Restoration of a native, edible, and marketable predator to control schistosome-transmitting snails may offer benefits for public health, ecosystem health, and poverty alleviation.