“African Eye worm”
By Amanda Green
Loa Loa is a parasite known more commonly as the “African Eye Worm”. This may be one of the most feared of the parasites. They are classified as filarial worms, meaning they thrive in human tissues. Before the 1920’s , Loa Loa infections occurred more frequently in the United States now it is more commonly found in West Africa and equatorial Sudan. It prefers areas with hot, wet climates, like swamps and rainforests. They are cylindrical and have a cuticle with three main outer layers. This protects the nematodes (larvae) so they can invade the digestive tracts of animals. The outer layers are non cellular. The adult Loa Loa is a thin small worms ranging in length from 20 – 70 mm long and 350 – 430 mm wide. Males are smaller than the females. Loa Loa was first described in 1770 by a French surgeon, Mongin. He was the first surgeon to try to remove a worm from the eye of a woman in Santa Domingo. He was unsuccessful. Another observation came form a French ships surgeon, who observed an eye worm in slaves being taken to the West Indies from Africa in 1778. The first person to identify the microfilaria of Loa Loa in 1890 was Dr. Patrick Mason when he was invited to examine blood smears with Dr. Stephen Mackenzie. This person was thought to have “sleeping sickness of the Congo.” To reproduce the female produces a pheromone to attract males. After mating the female produces large numbers of active embryos called microfilaria. These microfilaria find their way to the blood stream where they can be transmitted through a bite to the next host. Loa Loa is an obligate endoparasite that feeds on fluids in the tissues of humans. The parasite contains pharyngeal glands and intestinal epithelium that produce digestive enzymes that enable them to feed on the hosts’ body fluids. Extracellular digestion begins within the lumen and is finished...