Which of the following act as a vector for spreading Onchocerciasis?
Onchocerciasis is caused by Onchocerca volvulus and is a major cause of blindness. It is transmitted by Simulium damnosum, a black fly that breeds in areas of rapidly flowing streams. The fly picks up microfilariae from the skin of the infected person, where it matures into larvae that become adult worms in 1 year. The adult parasite produces cutaneous nodules which are 5-25 mm in diameter on the trunk, thighs, arms, head, and shoulders. In the eye it causes nummular keratitis and sclerosing keratitis. Death of the microfilariae causes an intense inflammatory reaction and severe uveitis, vitritis, and retinitis. It is diagnosed by skin biopsy and microscopic examination looking for live microfilariae. The preferred treatment for onchocerciasis is with nodulectomy and ivermectin. Ref: Cunningham, Jr. E.T., Augsburger J.J., Correa Z.M., Pavesio C. (2011). Chapter 7. Uveal Tract & Sclera. In P. Riordan-Eva, E.T. Cunningham, Jr. (Eds), Vaughan & Asbury's General Ophthalmology, 18e.
Tsetse fly
Culicoides midge
Simulium damnosum
Bugs of subfamily Triatominae