 loa loa is the filarial nematode (roundworm) species that causes loa loa filariasis. it is commonly known as the "eye worm". its geographic distribution includes africa and india.schmidt, gerald et al. "foundations of parasitology". 7th ed. mcgraw hill, new york, ny, 2005. l. loa is one of three parasitic filarial nematodes that cause subcutaneous filariasis in humans. the two other filarial nematodes are mansonella streptocerca and onchocerca volvulus (causes river blindness). maturing larvae and adults of the "eye worm" occupy the subcutaneous layer of the skin &ndash; the fat layer &ndash; of humans, causing disease. the young larvae develop in horseflies of the genus chrysops (deer flies, yellow flies), including the species c. dimidiata and c. silacea, which infect humans by biting them. == biology == ===morphology=== loa loa worms have a simple body including a head, body, and tail. males range from 20mm to 34mm long and 350Î¼m to 430Î¼m wide. females range from 20mm to 70mm long and are about 425Î¼m wide. ===life cycle=== three species involved in the life cycle include the parasite loa loa, the fly vector, and the human host:"filariasis". parasites and health. center for disease control. * a vector fly bites an infected human host and ingests microfilariae. * microfilariae move to the fat body of the insect host. * microfilariae develop into first stage larvae, second stage, then third stage larvae. * third stage larvae (infective) travel to the proboscis of fly. * an infected vector fly bites an uninfected human host and the third stage larvae penetrates the skin and enters human subcutaneous tissue. * larvae mature into adults, who produce microfilariae that have been found in spinal fluid, urine, peripheral blood, and lungs. == disease ==  ===pathogenesis=== loa loa parasites infect human hosts by travelling from the entry site through subcutaneous tissues and causing inflammation in the skin wherever they travel. if a parasite stops in one place for a short period of time, the human host will suffer from local inflammation known as calabar swellings. these are localized, tense, inflammatory pruritic subcutaneous edema seen in joints of extrem
Parasitic_diseases