COLUMBUS, Ohio Small changes in agricultural and sanitation practices may eliminate the spread of a disease that affects some 200 million people living in developing nations around the world.

Researchers working in remote farming villages in western China report that providing medicine to infected people and animals, along with modifying irrigation and waste treatment practices could reduce, or even eliminate, the long-term transmission of schistosomiasis.

Schistosomiasis is a disease that can affect the liver, the gastrointestinal tract or the bladder. The researchers report their findings in a recent issue of the Proceedings of the National Academy of Sciences.

Right now, governments in many countries where the disease is prevalent provide medicine to afflicted people, as well as a pesticide that kills the snails that carry a larval stage of the parasitic worm, Schistosoma the cause of schistosomiasis. Farmers either spray the pesticide, or apply it as a paste-like mixture, on the soil where snails dwell.

But this dual approach only temporarily reduces infection rates in many areas, said Song Liang, the study's lead author and an assistant professor of environmental health sciences at Ohio State University.

We know agricultural and irrigation practices play a large role in the transmission of schistosomiasis, he said. Altering these practices, in addition to providing the medicine and pesticide, may be the best way to drastically reduce, or even eliminate, the spread of the disease.

The practices Liang refers to include building concrete walls to line irrigation ditches, which would radically change snail habitat, as well as using a device that kills most of the Schistosoma eggs in human and animal waste the primary fertilizer in these areas.

Schistosomiasis is caused primarily by three major species of Schistosoma, parasitic worms that lay eggs in the bowels of humans and animals. The dis
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Contact: Song Liang
SLiang@cph.osu.edu
614-293-8263
Ohio State University
31-May-2007