Transmission: Onchocerciasis is caused by the parasitic worm Onchocerca Volvulus. The bite from Simulium black flies carries the parasitic worms. Within the black fly, the parasitic worms take two weeks to develop into their infectious forms. When a human is bitten, the parasitic worms infect the person’s skin and reproduce within the human hosts. 

Symptoms: Categorized by itching, depigmentation, loss of skin elasticity, itchy skin rash and in some cases, loss of visual activity and eventual blindness. 

Hosts: Simulium black flies that often breed near fast running water such as streams and rivers.

Treatment: Ivermectin is used for 6 months or as long as the larvae live. The problem with treatment is that Ivermectin does not treat adult worms meaning they are still able to reproduce. A new chemotherapy,  anti-Wolbachia chemotherapy, is currently being studied to stop the adult worms as well. 

Risk: Living within proximity to bodies of water that harbor Simulium black flies. Onchocerciasis was thought to be eradicated in Latin America expect in Brazil and Venezuela. 

Prevention: Currently prevention is being targeted at controlling black fly populations that harbor Onchocerca Volvulus. Travellers and community member should take caution in areas where this species of fly resides. By wearing protective clothing, boots, and approved bug repellent can potentially lower the risk of infection.