The onchocerciasis worm can be transmitted to you through the bite of an infected Simulium blackfly. The parasitic worm can live for up to 14yrs in your body. The backfly breeds in fast-flowing rivers and streams. When the fly bites you, it deposits the immature young(larvae) which mature to adulthood and produce millions of tiny worms(microfilaria).Adults emerge after 8-12days and live for up to 4wks. A few young may transform into an infective form within the blackfly, which are then injected into the person from whom the next meal is taken.
Attribution: Avallain