Screening Method Developed for River Blindness

Scientists have developed a screening method that rapidly identifies individuals with active river blindness, or onchocerciasis.

The parasitic disease afflicts an estimated 37 million people and is caused by the larvae or microfilariae of the worm Onchocerca volvulus. The vast majority of onchocerciasis infections occur in sub-Saharan Africa, with the largest disease burden in rural Nigeria, and to a lesser degree in Yemen and in parts of Central and South America.

Scripps Research Institute (La Jolla, CA, USA) scientists used liquid chromatography-mass spectrometry (LC-MS) based metabolomics on an African sample set comprised of 73 serum and plasma samples to reveal 14 biomarkers that showed excellent discrimination between O. volvulus-positive and negative individuals.

Application of the biomarkers to an additional sample set from onchocerciasis endemic areas where long-term Ivermectin treatment was successful revealed that the biomarkers could distinguish individuals with worms of compromised viability from those with active infection.

The scientists plan to develop a diagnostic kit that can be used in the field to test for onchocerciasis and other parasitic diseases. There have not been any accurate, sensitive means of diagnosing O. volvulus infection. Clinical diagnostics are desperately needed in order to achieve the goals of controlling and eliminating onchocerciasis and neglected tropical diseases in general.

"A sensitive and reproducible diagnostic test for this disease is crucial for the success of worldwide control and elimination programs," said Kim Janda, Ph.D., a professor in the departments of chemistry and immunology and microbial science, member of The Skaggs Institute for Chemical Biology, and director of The Worm Institute for Research and Medicine (WIRM) at Scripps Research. "This diagnostic tool could be a game-changer for how the disease will be treated in the future."

The study was published online on October 5, 2010, by the journal PLOS Neglected Tropical Diseases.

Related Links:
Scripps Research Institute
The Skaggs Institute for Chemical Biology
The Worm Institute for Research and Medicine