In this episode, Dave Little talks with Reed Ozretich who specialises in a One Health approach to aquaculture in the context of a changing climate. He's been working on a Belmont-funded project in Brazil and Ivory Coast coordinated by Giulio de Leo, at Stanford University, but working with local partners focusing on understanding the dynamics of snails as vectors for schistosomiasis; what, if any, is the role of farmed fish in controlling them? Reed talks here about his recent work in Ivory Coast with Professor Eliezer N’Goran. at UFHB in Abidjan.
Reed’s work focused on schistosomiasis, which is a disease called caused by members of the helminthic parasite, genus Schistosoma, of which six species cause this disease. In mammals. There are over 200 million people right now are infected with just this myosis, most of them Africa. What's particularly insidious about this disease is that after infects the host, the human host or animal host, these worm-like parasites, travel to either the ball or the bladder region of the body and settle in the soft tissues there sexually reproducing for years and years and producing thousands of eggs. The symptoms therefore, of the schistosoma producing these eggs are are caused by the body's immune response, and they can include chronic fatigue anywhere, anywhere from chronic fatigue to bowel cancer and left untreated. Also, the death of the host. Because it's a water borne illness, those who are in regular contact with infested water bodies are particularly vulnerable and at risk to the disease. And these include women and young children, especially who play around in the water.
However schistosomiasis, the schistosoma parasite requires an intermediate snail host to complete their life cycle. This is where aquaculture comes in, as there are some fish species that will feed on the snails. If these can be cultured in affected waters, they could provide a biological control mechanism whilst also providing nutritious food for local communities.
Aquatic snails are the intermediate hosts for the schistosoma parasite
The research has identified the West African Lungfish (Protopterus annectens) as a potential candidate and plans are in place for a return visit to the Ivory Coast in early 2023 to conduct further survey work on lung fish populations and dietary habits.
Climate change adds a further dimension to the study, as it affects the epidemiology of the disease in many ways, though changes in rainfall patterns and water bodies, ecological changes such as in aquatic vegetation, and coping strategies such as investment in reservoirs which has spread disease through migratory labour.
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Read more about the project in this blog post