What is lymphatic filariasis?

Lymphatic filariasis is an infectious, parasitic disease caused by nematodes (roundworms). The disease is caused by the presence of thread-like worms, called filariae, in the lymphatic vessels and lymph nodes of the body. The lymphatic channels drain excess fluid from the body and play a role in the infection-fighting immune system.

Lymphatic filariasis is transmitted by mosquitoes. A blood meal taken from an infected individual is then injected into an uninfected person. Unlike lifelong residents, travelers to affected regions usually do not accrue sufficient exposure to the parasite to generate the severe complications discussed in this article.

Lymphatic filariasis most commonly occurs in developing countries with a tropical climate. Wuchereria bancrofti, Brugia malayi, and Brugia timori are the specific worms that cause the infection. The larvae enter the body at the time of the mosquito bite and travel to the lymphatic system, where they mature into adult worms. The adult worms can live for years in the lymphatic system, and they produce immature forms that circulate in the blood.

Lymphatic filariasis causes blockage of the lymphatic channels, leading to swelling and eventual scarring of the legs, known as elephantiasis, and in men, to swelling of the scrotum, or hydrocele. These symptoms are extremely disabling. These conditions are also disfiguring, and, in some communities around the world, people with the disease may be shunned.

Globally, the disease affects more than 120 million people. The disease has been eradicated from the United States, with the last known case occurring in the 1920s. Lymphatic filariasis is found in the tropics of Asia, Africa, the Pacific, the Caribbean, and South America. Haiti, the Dominican Republic, Guyana, and Brazil are the affected countries in the Americas. Travelers to affected countries should be vigilant about mosquito protection (Source CDC).

Seek prompt medical care if you notice swelling of your genitals or extremities, or if you have been in an affected area of the world and think that you may have been bitten by a mosquito.


What are the symptoms of lymphatic filariasis?

Common symptoms of lymphatic filariasis

Typically, lymphatic filariasis does not have clinical symptoms, such as flu-like symptoms, fever, or vomiting. In fact, most people with lymphatic filariasis are unaware they have i... Read more about lymphatic filariasissymptoms


What causes lymphatic filariasis?

Mosquitos transmit the parasites from person to person, depositing the larvae through the skin from a bite. The larvae enter the lymphatic system and develop into worms over time, typically six to 12 months. These worms can live in their human host for several years, during which millions of immature forms known as microfilariae circulate in the blood. If the infected person is bitten by a mosq... Read more about lymphatic filariasiscauses


How is lymphatic filariasis treated?

Treatment for lymphatic filariasis depends on whether the infection is active or has progressed to complications.

Treatment for active infections

Diethylcarbamazine (DEC) is the drug of choice for treating lymphatic filariasis. This drug effectively kills the microfilariae.

Treatment for complications

Complications of lymphatic filariasis, such ... Read more about lymphatic filariasistreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 6, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

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