Lymphatic Filariasis

lim-ˈfa-tik fi-lə-ˈrī-ə-səs

Photo of severely swollen feet and ankles

Lymphatic filariasis (LF) is a neglected tropical disease (NTD) caused by microscopic, thread-like worms. The adult worms live in the human lymph system, which maintains the body’s fluid balance and fights infections. LF is spread from person to person by mosquitoes. People with LF can suffer severe, permanent disability. Some are unable to work because of their disability, harming their families and communities. You cannot get infected with LF in the U.S. However, LF continues to pose a health risk in the U.S. territory of American Samoa, and efforts to eliminate the disease are underway.

Quiz

Key Facts

  • Lymphatic filariasis (LF) is a parasitic disease caused by three species of microscopic, thread-like worms.
  • The disease spreads from person to person by mosquito bites.
  • If you live in or travel to an area with lymphatic filariasis, avoiding mosquito bites is the best way to prevent it.
  • LF is a neglected tropical disease that causes substantial illness for more than 120 million people globally.
  • Neglected tropical diseases are infectious diseases that cause devastating illness for more than 1 billion people.

Media

Mosquito
Mosquitoes Spread LF

Lymphatic filariasis, considered globally as a neglected tropical disease (NTD), is a parasitic disease caused by microscopic, thread-like worms. The adult worms only live in the human lymph system. The lymph system maintains the body’s fluid balance and fights infections. Lymphatic filariasis is spread from person to person by mosquitoes.

Swollen feet being washed with soapy water
LF’s Devastation

Lymphatic filariasis is a leading cause of permanent disability worldwide. Some people will develop lymphedema (a complication of LF). However, proper care of patients with lymphedema can help them feel better and prevent the lymphedema from getting worse.

Young boy taking pills
Eliminating LF

Lymphatic filariasis is targeted for elimination globally. The elimination strategy is based on annual treatment of whole communities with medications that prevent the disease from spreading. Hundreds of millions of people are being treated each year.

Photo of older woman's swollen feet
The Impact of NTDs

Neglected tropical diseases (NTDs) are a group of parasitic and bacterial diseases that cause substantial illness for more than one billion people globally. Affecting the world’s poorest people, NTDs impair physical and cognitive development, contribute to mother and child illness and death, and make it difficult to earn a living.

Prevention Tips

Avoid mosquito bites. People who live in or travel to an area with lymphatic filariasis should:

  • Sleep under a mosquito net
  • Wear long sleeves and trousers
  • Use mosquito repellent on exposed skin between dusk and dawn.
Page last reviewed: January 28, 2020