History of Discovery

Onchocerciasis is a parasitical disease caused by the filarial worm Onchocerca volvulus.  It is predominately found in Africa, the Arabian Peninsula, and in South Africa.  Only when explorers entered these regions, was the disease recognized for the first time.  The diseased people were observed to experience blindness of unknown cause as well as scaly, itchy, nodular skin, which was known as kru kru or craw craw in West Africa. (1)

  1874 The subcutaneous microfilaria are discovered by John O’Neill, an Irish Naval surgeon, while examining skin-snips from craw-craw patients in Ghana.  
1893 Zoologist Rudolf Leuckart first describes the morphology of adult worms in subcutaneous nodules.
1890 Patrick Manson observes and identifies the adult worms.  
1904 Emile Brumpt recognizes that the microfilariae come from the adult worms living in subcutaneous nodules and that the infection occurs most commonly along river banks.
1917 Rodolfo Robles publishes findings on a “new disease” from Guatemala associated with subcutaneous nodules, anterior ocular lesions, dermatitis, and microfilariae.  
1920 The role of microfilariae in causing skin lesions is established by A. Lacroix and Jean Montpellier.  
1923 Scottish parasitologist Breadablane Blacklock working in Sierra Leone, establishes that O. Volvulus (and therefore onchocerciasis) is transmitted by sand flies .  

Jean Hissette describes the link between microfilaria and blindness in the Belgian Congo

Information for this section was compiled from sources (1) and (5)