Fighting a life-threatening disease with … shrimp?
Researchers are working in Nigeria to help curb the spread of a potentially deadly parasite. And it all starts with a tiny, bug-eyed crustacean.
Schistosomiasis is a potentially deadly parasitic disease that damages internal organs and affects more than 200 million people worldwide, coming only second to malaria in terms of human suffering.
If you had never heard of this disease until now, you're not alone. Though scientists have been studying schistosomiasis (also known as snail fever) for decades and even developed a promising drug in the late 1970s, its disastrous impact has only worsened, indicating that drug treatment alone is not effective.
Knowing this, a team of researchers from Israel's Ben-Gurion University traveled this summer to western Nigeria, where schistosomiasis is widespread. Many villagers there bathe and do laundry in rivers that carry the parasitic snail and end up infecting and re-infecting themselves with the disease. Working with officials from Ibadan University in Nigeria, the researchers are trying to help eradicate the disease in a natural way: using a tiny crustacean called a prawn to feed on the type of snail that carries the disease. The idea is that if a region's freshwater ecosystem includes more prawns, they will feed on the contaminated snails and reduce the likelihood that the snails would transmit the disease to humans.
The team published a study on their findings in August 2019 in Nature's Scientific Reports.
"The project will eventually be developed into a larger field of study and demonstrate the use of biocontrol to help eradicate disease,” said Professor Amir Sagi, who led the research team in Nigeria through Ben-Gurion University's Department of Life Sciences and National Institute for Biotechnology.
The method has proved successful in other parts of Africa and around the world. An organization called Project Crevette (French for prawn), with which the Israeli team has collaborated for the past two years, claims to have reduced infection rates by 80 percent only six months after restoring the prawn population in Lampsar, Senegal. Today, the section of river that borders Lampsar is confirmed to be completely free of any schistosomiasis-transmitting snails.
The problem, though, is international buy-in. Though the method clearly works, many impoverished areas of Africa, where snail fever is a major concern, have yet to see more prawns enter their region's rivers and work their magic. This is due to a combination of factors, one being lack of government support and resources, and another being deficits in communication between countries.
The Israeli researchers' goal is to bridge those gaps by bringing their own resources and education to those far-flung areas. They're also trying to promote the prawns as a viable crop that would boost the local economy.
"We want to teach farmers how to produce the prawns so they can sell some for the markets as a crop, because they are delicious, and the rest will be released in the river with an agreement of the health ministry," said Amit Savaia, who traveled to Senegal after graduating from BGU and worked with Project Crevette. He was among the first to prove that when the freshwater prawns are reintroduced into the river, they eat the contaminated snails, but don't spread the disease themselves.
As researchers from Israel make headway on the prawn method, other research bodies are seeing the benefits and getting on board as well. A group of scientists from Stanford University, who published a study two years ago laying out the promising results of Project Crevette, are trying to expand the method to more underdeveloped and underserved communities. Their initiative, called the Upstream Alliance, explores whether natural solutions like the prawn method can be viable and sustainable on larger scales.
Said the study's authors in their analysis: "Where drugs alone fail to control schistosomiasis due to rapid reinfection, prawns may offer a complementary strategy."
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