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 only 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 and even permanent disability. Affected people frequently are unable to work because of their disability, and this harms their families and their communities. LF affects over 120 million people in 72 countries worldwide. You cannot get infected with the worms in the continental United States.

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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 considered a neglected tropical disease because it causes substantial illness for more than 1 billion people globally.
  • Neglected tropical diseases are infectious diseases that cause devastating illness for more than 120 million people.

Media

Swollen feet being washed with soapy water
LF’s Devastation

Lymphatic filariasis is a leading cause of permanent disability worldwide. Communities frequently shun and reject women and men disfigured by the disease. Affected people frequently are unable to work because of their disability, and this harms their families and their communities.

Young boy taking pills
Treatment for LF

Experts believe that lymphatic filariasis can be eliminated globally. The elimination strategy is based on annual treatment of whole communities with combinations of drugs that kill the microscopic worms. 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

Avoiding mosquito bites is best. People who live in or travel to an area with lymphatic filariasis should also:

  • Sleep under a mosquito net
  • Wear long sleeves and trousers
  • Use mosquito repellent on exposed skin between dusk and dawn.
Page last reviewed: January 21, 2022