Loa loa: The African Eye Worm Introduction: A parasite is an organism in or on another living organism obtaining from it part or all of its organic nutriments, commonly exhibiting some degree of adaptive structural modifications, and causing some degree of real damage to its hosts‘ (Thomas, Renaud, and Guegan, 2005). One of the many parasites is the filarial African eye worm, Loa loa. Loa loa belongs to class Secernentea, subclass Spiruria, order Spirurida, super family Filarioidea, and family Onchocercidae. These parasites are located in the areas of the rain forest near equatorial Sudan and in West and Central Africa.
Loa loa has a simple head with no lips, a long, slender body, a rounded tail, and eight cephalic papillae (Loa loa). Besides the head and tail, the cuticle is covered with irregular, small bosses. Female Loa loa is generally five to seven centimeters long and the male is from two to three and a half centimeters long. Loa loa is asymmetrical meaning they have three pairs of preanal and five pairs of postanal papillae (Loa loa). The spicules of Loa loa are uneven and dissimilar. The vulva of the female is about two and a half millimeters from the anterior end and the tail is about 265-300 um long (Loa loa).
Microfilariae of this parasite possess a sheath that does not stain with Giemsa but is with Delafield’s haematoxylin and is stain blue-gray. Loa loa is a parasite that lives in humans and other primates, transmitted by mango flies and horse flies. They generally live under the human skin and infrequently crawl across the surface of the eye (Vodopich and Moore, 2005). Life Cycle: Loa loa is a filarial nematode that is transmitted to humans by Chrysops flies; mango and horse flies. Once inside the human body, the infective larvae develop into a mature adult in a slow process. This process can take about a year.
During this time, the larvae lives and move around in the layers of the human skin. During the growth and development period, Loa loa makes repeated trips to the connective tissues, where the host, humans, usually notices it. At the age of maturity, male Loa loa can be 3-3. 4 centimeter x 0. 35-. 043 millimeters and for the female 5. 7 x 0. 5 millimeters (Micrifilariae of Loa loa). Once the microfilariae reinfect the fly, they would undergo two stages of growth. These stages would then infect the larvae that can transmit back to the humans. An adult worm can live up to about fifteen years. [pic]
Modified from an original image taken from the “Parasitological Diagnostics Aids Page. ” Disease Characteristics: One main type of disease that Loa loa cause is Loiasis, also known as lymphatic filariasis. Diagnosed is shown by microfilariae in the blood. It spread from human to human by mosquito bites. The microscopic worm is passed from the mosquito to humans by entering through the skin and is travel to the lymph vessels. Usually, people who are infected with lymphatic filariasis do not feel any symptoms until the adult worm die. Loiasis can permanently damage the lymph system and kidneys but is not a life threatening disease.
When the lymph system does not work right, it causes fluid to collect and swells the arms, breasts legs, and mostly for men, the swelling of the genital area. The swelling and failure of the lymph system increases the chances of a person getting sick because it makes the body difficult to fight the germs and infections. You can get the swellings surgically removed. This disease also causes elephantiasis, hardening and thickening of the skin. Lymphatic Filariasis is a leading cause of permanent and long-term disability worldwide. This disease can cause people to experience pain, deformity, and sexual disability.
Many women who suffer from this disease will never have the chance marry or their spouses and family members will reject them. People with lymphatic filariasis is unable able to work and can make their life very difficult to live. If you are infected with lymphatic filariasis, you should take a yearly dose of medicine that kills the worms from circulating in your blood. The medication will kill the microscopic worms in your blood but not the adult worms. By taking the medicine, it does not guarantee that it will kill all the worms in your body. This just prevents you from spreading the disease to other people.
If you are living in areas that are infected by this disease, sleep under a mosquito net, preventing you from being bitten by the infected mosquitoes. Also, use mosquito repellant on your skin between dusk and dawn because it is usually the hours where the mosquito’s bites occur. When the adult worm dies, it will cause the human body to swell within the arms, legs, breast, and genitals. To prevent the swelling from getting worse, carefully wash the swollen areas with soap and water every day. Use anti-bacterial cream on the wounds to stop bacterial infections and keep the swelling from getting worse.
If your arm or leg is swollen, it is good if you exercise to improve the lymph flow and the fluids in your body. A characteristic of Loiasis is the causing of Calabar swellings. Calabar swellings are temporary soft-tissue swellings usually around the joints. They are hot and painless. This type of swelling is due to the toxins that were released by Loa loa. These swellings can last from one to three days. Calabar swellings develop rapidly and can have serious complications; such as cardiomyopathy, encephalopathy, nephropathy, and pleural effusion (Filariasis).
Calabar swellings will disappear when the worm moves on. Current News or Research: Diethylcarbamazine is a microfilaricide that may enhance adhesion of gametocytes via antibody-dependent and independent mechanisms (Filariasis). Research shows that Diethylcarbamazine induce immobilization of microfilariae by decreasing muscle activity. To decrease risk of adverse effects, low doses are recommended for the first three days of treatment and higher doses are recommended for Loa loa from four to twenty-one days.
Doses of Diethylcarbamazine starts at fifty milligrams and increased slowly in frequency and amount. Conclusion: The parasite, Loa loa, cannot kill you but they can cause swellings and many infections to your body. Their long, slender body with a simple head and no lips can cause a person to live a life that no one wants to live. Rejections of job offers and disown by family members can hurt a person deeply. Knowing that no one would marry you, no able to experience having children, and not knowing what it feels like to have a family, can devastate a human being.
This simple, little parasite can destroyed one’s life. Besides not having the chance to experience life, deformity of swellings within the arm, leg, breasts, or even genital areas can bring a person’s self-esteem down. Human beings as being a host for this parasite can be a scary thing. Not knowing if this tiny parasite would ever enter the United States and if one of us could be infected next. No one knows but as technology advance, so does the medication to treat Loa loa. Literature Cited: Filariasis. Retrieved March 6, 2006 from http://www. emedicine. com/med/topic794. htm.
Loa loa. Retrieved March 1, 2006 from http://ucdnema. ucdavis. edu/imagemap/nemmap/ Ent156html/nemas/loaloa. Micrifilariae of Loa loa. Retrieved March 1, 2006 from http://www. btinternet. com/~ukneqas. parasitologyscheme/Blood_Scheme/Teaching_Information/Micrifilariae_of_Loa_loa/micrifilariae_of_loa_loa. html. Thomas, Frederic, Renaud, Francois, and Guegan, Jean-Francois. Parasitism & Ecosystems. 2005. Oxford University Press Inc. New York. Pg 156. Vodopich, Darrell S. and Moore, Randy. 2005. Biology Laboratory Manual, Seventh Edition. The McGraw-Hill Companies, Inc. The United States
