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Disease Profile

Lymphatic filariasis

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

<1 / 1 000 000

US Estimated

Europe Estimated

Age of onset

All ages



B74.0 B74.1 B74.2


Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Filariasis; Elephantiasis; Wuchereria Bancrofti infection;


Parasitic diseases


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]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Swollen lymph nodes
Predominantly lower limb lymphedema
30%-79% of people have these symptoms
Circulating immune complexes

[ more ]

Hyperpigmentation of the skin
Patchy darkened skin
Inflammation of the lymph nodes
5%-29% of people have these symptoms
Abnormal lung morphology
Abnormality of lung structure
Abnormality of the lungs
Abnormally shaped lung
Unusal lung shape

[ more ]

Hydrocele testis
Opportunistic bacterial infection
Inflammation of testicles
Restrictive ventilatory defect
Stiff lung or chest wall causing decreased lung volume
Vaginal hydrocele
1%-4% of people have these symptoms
Ankle swelling
Blood in urine
Knee osteoarthritis
Nephrotic syndrome
No social interaction
High urine protein levels
Protein in urine

[ more ]

Urethral obstruction


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]

Learn more

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.


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

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