infectious diseases
Onchocerciasis (River Blindness)
Pathophysiology of Onchocerciasis
Onchocerciasis is spread by blackflies (Simuliumspecies) that breed in swiftly flowing streams (hence, the term river blindness). Many blackfly bites are needed before disease develops. Infective larvae inoculated into the skin during the bite of a blackfly develop into adult worms in 12 to 18 months. Adult female worms may live up to 15 years in subcutaneous nodules. Females are 33 to 50 cm long; males are 19 to 42 mm long. Mature female worms produce microfilariae that migrate mainly through the skin and invade the eyes. 