Loiasis, called African eye worm by most people, is caused by the parasitic worm Loa loa. It is passed on to humans through the repeated bites of deerflies (also known as mango flies or mangrove flies) of the genus Chrysops. The flies that pass on the parasite breed in certain rain forests of West and Central Africa. Infection with the parasite can also cause repeated episodes of itchy swellings of the body known as Calabar swellings. Knowing whether someone has a Loa loa infection has become more important in Africa because the presence of people with Loa loa infection has limited programs to control or eliminate onchocerciasis (river blindness) and lymphatic filariasis (elephantiasis). There may be more than 29 million people who are at risk of getting loaisis in affected areas of Central and West Africa.
Image: L: Microfilaria of L. loa in a thin blood smear, stained with Giemsa. R: Picture of Chrysops silacea feeding on a volunteer. Credit: DPDx