Washington University researchers are working to put an end to River Blindness, an illness caused by parasites that affects some 37 million people in 30 countries. Scientists at Washington University in St. Louis have been given a $2 million grant from the Bill & Melinda Gates Foundation to try to create tests that would eradicate the disease.
Medical professor Gary Weil, an MD who specializes in infectious disease, says people in the United States don’t get the parasites that cause blindness, skin problems and elephantiasis, but there is a similar parasite here … it’s the one that causes heartworms in dogs.
Known formally as onchocerciasis, the disease mostly afflicts residents of sub-Saharan Africa. River blindness is caused by a parasitic worm, Onchocerca volvulus, and is spread by the bites of black flies that breed in fast-flowing rivers, hence the name river blindness. While the disease can lead to blindness, it more commonly causes less severe visual impairment, disfiguring skin lesions and severe itching.
“River blindness remains a devastating illness for millions of people, most of whom live in poverty in Africa and Latin America,” Weil says. “We have most of the tools we need to eliminate this disease, but improved diagnostic methods are necessary to help steer the program.”
Weil says current tests do not detect the presence of adult female worms, which can live in nodules under the skin for years.
“One challenge we face as we work to eradicate this disease is to accurately determine whether mass distribution of the medication has succeeded to the point where there is no risk that transmission of new cases will resume,” Weil says.
His research group will search for biological “markers” that indicate the presence of living adult female worms in humans. They will look for excretion products or snippets of genetic material from the worms in blood and urine samples. Weil will work with Reid Townsend, MD, PhD, professor of medicine, and Makedonka Mitreva, PhD, assistant professor of medicine and of genetics, to identify markers that are found exclusively in people infected with onchocerciasis, but not in those who are healthy or in people with infections caused by other parasitic worms. Townsend brings to the project extensive expertise in proteomics (the identification of proteins in biological samples), and Mitreva is an authority on the analysis of DNA and genomes of nematode worms, including the parasitic worm that cause river blindness. The first year of the project will focus on identifying the biomarkers.
In the second year, the researchers will work toward developing a test that can easily and accurately detect the presence of onchocerciasis.
“We’re using a multidisciplinary approach to develop a new tool that will help the international effort to eradicate river blindness,” Weil says. “With recent advances in genomics and proteomics, we’re optimistic that we can accomplish this task. ”