River blindness, or onchocerciasis, the second-leading infectious cause of blindness worldwide (after trachoma), has long been attributed to a parasitic nematode—Onchocerca volvulus—that is transmitted by the bite of black flies commonly found along rivers and streams in the tropics. Now, an international team of scientists from the United States, Germany, and England has found evidence that the main culprit responsible for disease isn't the worms themselves but bacteria that they carry (Science. 2002;295:1892-1895).
Stephenson J. River Blindness Coconspirator. JAMA. 2002;287(14):1794. doi:10.1001/jama.287.14.1794-JWM20004-2-1