National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Lymphatic filariasis


Other Names:
Filariasis; Elephantiasis; Wuchereria Bancrofti infection; Filariasis; Elephantiasis; Wuchereria Bancrofti infection; Filarial elephantiasis; Malayi tropical eosinphilia; Wuchereriasis; Bancroftian filariasis; Elephantitis See More
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Lymphatic filariasis is a parasitic disease caused by microscopic, thread-like worms that only live in the human lymph system, which maintains the body's fluid balance and fights infections. It is spread from person to person by mosquitoes. Most infected people are asymptomatic and never develop clinical symptoms. A small percentage of people develop lymphedema, which may affect the legs, arms, breasts, and genitalia; bacterial infections that cause hardening and thickening of the skin, called elephantiasis; hydrocele (swelling of the scrotum) in men; and pulmonary tropical eosinophilia syndrome. Treatment may include a yearly dose of medicine, called diethylcarbamazine (DEC); while this drug does not kill all of the adult worms, it prevents infected people from giving the disease to someone else.[1]
Last updated: 4/9/2016
The main treatment for this disorder is the use of major anti-parasiticide drugs; examples of these include ivermectin, albendazole, and diethylcarbamazine (DEC). These drugs work to get rid of the larval worm, to inhibit reproduction of the adult worm, or to kill the adult worm.[2] For individuals who are actively infected with the filarial parasite, DEC is typically the drug of choice in the United States. The drug kills the microfilaria and some of the adult worms. DEC has been used world-wide for more than 50 years. Because this infection is rare in the U.S., the drug is no longer approved by the Food and Drug Administration (FDA) and cannot be sold in the United.States. Physicians can typically obtain the medication from the CDC after confirmed positive lab results. DEC is generally well tolerated. Side effects are in general limited and depend on the number of microfilariae in the blood. The most common side effects are dizziness, nausea, fever, headache, or pain in muscles or joints. Another treatment option, ivermectin, kills only the microfilariae.[3]

For individuals with clinical symptoms of the condition, treatment depends on the signs and symptoms the affected individual has. Lymphedema and elephantiasis are not typically indications for DEC treatment because most people with lymphedema are not actively infected with the filarial parasite. To prevent the lymphedema from getting worse, individuals should ask their physician for a referral to a lymphedema therapist so they can be informed about some basic principles of care such as hygiene, exercise and treatment of wounds.[3] Men with hydrocele (abnormal accumulation of fluid in the scrotum) may have evidence of active infection, but typically do not improve clinically following treatment with DEC. The treatment for hydrocele is surgery.[2][3] Surgery may also be performed to remove the remains of adult worms and calcifications developing around them. Treatment of elephantiasis of the legs usually consists of elevation and support from elastic stockings.[2]

In the tropical areas of the world, mosquito control is an important part of prevention of filariasis. Filariasis is usually a self-limited disease unless reinfection occurs. Therefore some cases, especially those brought into temperate regions of the world (i.e., North America), may be left untreated because there is no danger of spreading the disease.[2]
Last updated: 4/9/2016

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Lymphatic filariasis. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • You can obtain information on this topic from the Centers for Disease Control and Prevention (CDC). The CDC is recognized as the lead federal agency for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of the people of the United States.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
  • The United States Agency for International Development (USAID) launched the Neglected Tropical Diseases Initiative in 2006, the first global effort to support country programs to integrate and scale up delivery of preventive medication for five neglected tropical diseases: lymphatic filariasis, schistosomiasis, trachoma, onchocerciasis, and soil-transmitted helminthiasis. Click on the link to view information on this condition.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Lymphatic filariasis. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I have had this condition for past 3-4 years and just now have a diagnosis for it. I was born in Germany and lived all my life in the US and have never visited any other foreign country. I came down with this while living in North Carolina. I am not receiving much help as of yet and wonder what future treatment there is for me. I need help. See answer


  1. Parasites - Lymphatic Filariasis: Frequently Asked Questions. Centers for Disease Control and Prevention. June 14, 2013; http://www.cdc.gov/parasites/lymphaticfilariasis/gen_info/faqs.html.
  2. Filariasis. NORD. 2009; http://rarediseases.org/rare-diseases/filariasis/.
  3. Parasites - Lymphatic Filariasis: Treatment. CDC. June 14, 2013; http://www.cdc.gov/parasites/lymphaticfilariasis/treatment.html.