Lymphatic filariasis is a parasitic disease caused by microscopic, threadlike worms that only live in the human lymph system, which maintains the bodys fluid balance and fights infections. Lymphatic filariasis is a mosquitoborne parasitic disease that is caused by a filarial nematode wuchereria bancrofti, brugia malayi or brugia timori and is, within the group of neglected tropical diseases, an important cause of chronic morbidity. Parasitic worms multiply in the lymphatic system and release larvae into the blood. Lymphatic filariasis lf is transmitted by mosquitoes, so risk factors include those that are conducive to the life cycle of mosquitoes poor drainage, vector breeding sites poor sanitation vulnerability to mosquito bites due to low insecticidetreated net itn use, etc. Lymphatic filariasis is a neglected tropical disease ntd. Each microfilaria is enclosed in a dedicate sheath and measures about 0. Basic science of lymphatic filariasis devries cr indian. Lymphatic filariasis, which includes the advanced form, elephantiasis often incorrectly referred to as elephantitis, causes extensive disability in several tropical and subtropical regions of the world.
Lymphatic filariasis is a disease associated with parasitic infection of one of three different nematodes. Education and information about lymphatic filariasis biology, specifically the life cycle of brugia malayi. Skip directly to site content skip directly to page options skip directly to az link. These worms are lodged in the lymphatic system, the network of nodes and vessels that maintain the delicate fluid balance between the tissues and blood and are an essential component for the bodys immune system. Centuriesold art and texts from egypt, japan, africa, persia and india depict the disease. Elbeshbishi lymphatic filariasis elephantiasis over view infection by 2 nematodes. Education and information about lymphatic filariasis biology, specifically the life cycle of wuchereria bancrofti. The causative agents of lymphatic filariasis lf include the mosquitoborne filarial nematodes wuchereria bancrofti, brugia malayi, b. Filariasis is a parasitic disease caused by an infection with roundworms of the filarioidea type. J3s are inoculated into the skin when black fly bites. Endemic regions for filariasis lymphatic filariasis lf is the primary cause for lymphedema worldwide and is a painful and extremely disfiguring disease, which has been identified by the world health organization who as a leading cause for permanent and longterm disability in the world.
The extrinsic life cycle of the parasite is initiated when the mf are ingested by a mosquito vector during feeding on the host blood. Perhaps the most important discovery related to lymphatic filariasis was that made by patrick manson in 1877. Male worms are about 34 centimetres in length, and female worms are longer, measuring 810 centimetres. Like malarial parasite the life cycle of filaria bancrofti is digenetic involving two hosts. Lymphatic filariasis is caused by three species of filaria namely wuchereria bancrofti, brugia malayi and brugia timori. The threadlike, parasitic filarial worms wuchereria bancrofti and brugia malayi that cause lymphatic filariasis live almost exclusively in humans. There are three species of these nematodes roundworms. Since 1991, in mexico, ivermectin has been administered twice a year to all residents in the onchocerciasis endemic foci which are mainly located in the coffee growing areas. Produced by the wellcome trust, this animation shows the complete life cycle of tiny parasitic worms as they move between human and mosquito hosts. Approximately 65% of those at risk reside in south and southeast asia, 30% in subsaharan africa and the remainder in other parts of the tropical world 2.
They circulate at night, when mosquitoes bite, in blood vessels near the skin. Manson was the first to look for an intermediate host for lymphatic filariasis microfilariae. Parasites develop to j3s in the musculature of the black fly and migrate to the mouthparts. Lymphatic filariasis can cause severe debilitation including disfiguration of limbs through elephantiasis that can lead to an inability to work and societal discrimination. Lymphatic filariasis an overview sciencedirect topics. Lymphatic filariasis discovery stanford university. Lymphatic filariasis is a human disease caused by parasitic worms known as filarial worms. Elephantiasis is also known as lymphatic filariasis. Serologic techniques provide an alternative to microscopic detection of microfilariae for the diagnosis of lymphatic filariasis. Patients with lymphatic filariasis lf face considerable physical, psychological and social disabilities. Following mating the female worm lays eggs which hatches to give rise to larvae or juveniles called microfilariae. Wuchereria bancrofti, brugia malayi, and brugia timori. They prevent affected adults and children from going to school, working, or fully participating in community life, contributing to stigma and the cycle of poverty. Another approach to prevention includes giving entire communities medicine that kills.
In 1877, he was finally able to pinpoint the microfilariae in mosquitoes. Morbidity management and control are important components of the global programme to eliminate. Patients with active filarial infection typically have elevated levels of antifilarial igg4 in the blood and these can be detected using routine assays. Stay tuned with byjus to learn more about what is filariasis elephantiasis, types of filariasis, filariasis elephantiasis symptoms, causes and. Although most people who are infected are asymptomatic, a.
The best way to prevent lymphatic filariasis is to avoid mosquito bites. Eliminate lymphatic filariasis gpelf is to eliminate the disease as a public health problem by 2020 1. Lymphatic filariasis, known as elephantiasis, puts at risk more than a billion people in more than 80 countries. Education and information about lymphatic filariasis treatment. Mass drug administration mda of ivermectin and albendazole for all members of the population, aiming to eliminate lymphatic filariasis from endemic areas. Filariasis filariasis is caused by a filarial worm which is a threadlike round worm inhabitiong the lymphatic system of humans. The aims of the programme are i to interrupt transmission with mass drug administration and ii to manage morbidity and prevent disability. India accounts for 30% of the worlds lymphatic filariasis burden. Linking to a nonfederal website does not constitute an endorsement by cdc or any of its employees of the sponsors or the information and products presented on the website. Lymphatic filariasis is caused by threadlike filarial worms.
Lymphatic filariasis is endemic in africa, asia, the indian subcontinent, the western pacific islands, focal areas of latin america, and the caribbean particularly haiti and the dominican republic fig. The mosquitoes that carry the microscopic worms usually bite between the hours of dusk and dawn. They belong to the group of diseases called helminthiases. Like onchocerciasis, lymphatic filariasis is caused by. What is lymphatic filariasis, know its causes, symptoms.
We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. Video explaining the parasitic life cycle of lymphatic filariasis in humans. The life cycle of lymphatic filariasis swelling an infected mosquito deposits larvae on the skin while biting, and the larvae enter the wound. When biting infective third stage larvae break out of the mosquito proboscis and enter the skin. The microscopic worms enter the human body via mosquito transmission in both children and adults and can live up to 57 years in the lymphatic system. Litomosoides sigmodontis is the only filarial nematode where the full life cycle, from larval delivery to the. Filariasis is caused by nematodes roundworms that inhabit the lymphatics and subcutaneous tissues. According to the global alliance to eliminate lymphatic filariasis, lymphatic filariasis is a parasitic disease caused by threadlike worms living in the human lymphatic system reference 1. Filariasis and elephantiasis are not different from each other since the latter is a type of filariasis, commonly known as lymphatic filariasis.
The infection is spread by mosquitoes and it is important to know the causes, symptoms and treatment of lymphatic filariasis to treat and prevent this condition. The skin may become thicker as well, and the condition may become painful. Contribution of migrant coffee labourers infected with onchocerca volvulusto the maintenance of the microfilarial reservoir in an ivermectintreated area of mexico. These are spread by bloodfeeding insects such as black flies and mosquitoes. Lymphatic filariasis is a disabling disease found in lowincome areas of many tropical and subtropical countries. Over 120 million have already been affected by it, over 40 million of them are seriously incapacitated and disfigured by the disease.
Lymphatic filariasis is the second biggest cause of longterm disability in the world. Lymphatic filariasis lf is one of the oldest and most debilitating diseases in the world. Some people, however, develop a syndrome called elephantiasis, which is marked by severe swelling in the arms, legs, breasts, or genitals. Wuchereria bancrofti, brugia malayi, or brugia timori. Most infected people are asymptomatic and never develop clinical symptoms. Lymphatic filariasis introduction stanford university.
Neglected tropical diseases are chronic infections that are typically endemic in low income countries. In the countries we work in there are millions of people already affected by lf and even more at risk of contracting the disease. The female worms measure 80 to 100 mm in length and 0. Because lymphedema may develop many years after infection, lab. Lymphatic filariasis although impacting millions does not have a high mortality rate. Lymphatic filariasis and the global elimination program. Adult worms live in the lumen of the small intestine. The threadlike worm that can cause lymphatic filariasis is a blooddwelling filarial nematode, also called a roundworm, from the aschelminth phyla reference 2. The global programme for the elimination of lymphatic filariasis gpelf was established in early 2000. Its caused by parasitic worms, and can spread from person to person through mosquitoes. Lymphatic filariasis is caused by the filarial nematodes of the species wuchereria bancrofti, brugia malayi and brugia timori that are transmitted by the bite of a number of mosquito species such as anopheles, culex and mansonia and ochlerotatus. The first species causes bancroftian filariasis and is responsible for 90% of the infection. They develop in adults that commonly reside in the lymphatics the number 2.
Fertilized female worms release embryonic offspring, called microfilariae, that enter the blood stream. Lymphatic filariasis elephantiasis life cycle youtube. Fertile eggs embryonate and become infective after 18 days to several weeks, depending on the environmental conditions optimum. Links with this icon indicate that you are leaving the cdc website the centers for disease control and prevention cdc cannot attest to the accuracy of a nonfederal website. On maturity, most of the infective l3 stage larvae migrate to the head and proboscis of the mosquito to get transmitted to the mammalian host during subsequent feeding. Lymphatic filariasis is an infection that affects the lymphatic circulation and is caused by wuchereria bancrofti, a parasitic threadworm.
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