What is lymphatic filariasis?

Lymphatic filariasis is a serious disease, with millions of people globally at risk. It can cause a range of symptoms, but is often characterised by abnormal enlargement of body parts.

Hassana from Nigeria sits in her home. She has lymphatic filariasis and her left leg is visibly swollen.

Lymphatic filariasis is transmitted via mosquito bite. The infection is usually first acquired during childhood.

It is one of a group of conditions known as neglected tropical diseases (NTDs). Once a person is infected, adult worms lodge in the body’s lymphatic vessels, affecting the lymphatic system. The worms can live for six to eight years, producing millions of larvae that circulate in the infected person’s blood.

The disease can cause abnormally enlarged body parts, which can be extremely painful and can lead to permanent physical changes. This condition, called lymphoedema, is highly stigmatised. In men, it can cause hydrocele, a form of lymphoedema that causes the scrotum to swell, leading to pain and disability.

The debilitating symptoms mean many people are unable to work, and children miss school to care for family members. The associated stigma can have a devastating impact on those affected, as well as their families and communities.

Watch our video to learn more about the disease.

120 million
people worldwide are infected with LF
40 million
people are incapacitated by the disease
885 million
people are currently at risk of LF

How is lymphatic filariasis treated?

A girl in Kenya receives her medication to protect against river blindness and lymphatic filariasis.


A combined dose of two medicines is given every year to people in high-risk areas by local volunteer community-directed distributors.

Ibrahim Hassan from Nigeria, who suffers from lymphatic filariasis.

Medical care

Although people suffering from advanced lymphatic filariasis cannot be cured, the symptoms can be eased through surgery and care.

A woman working in a science laboratory.


Research is undertaken to evaluate, inform and improve our programme strategies, helping to eliminate this disease more quickly and fairly.

What we’re doing

Sightsavers is fighting hard to eliminate lymphatic filariasis in the countries in which we work by 2030.

While river blindness is transmitted by the black fly and lymphatic filariasis by the mosquito, both diseases are caused by an infection of a filarial worm and often occur in the same places. Where they are co-endemic, Sightsavers coordinates treatments for these two diseases using Mectizan® tablets, donated by pharmaceutical company Merck Sharpe & Dohme (MSD), and albendazole tablets, donated by GlaxoSmithKline.

In countries where river blindness in not co-endemic, lymphatic filariasis is treated using diethylcarbamazine, produced by Eisai, and albendazole tablets, donated by GlaxoSmithKline.

In 2020, we provided more than two million treatments for LF worldwide. We also trained more than 137,000 local volunteers to distribute medication via mass drug administration to treat a range of neglected tropical diseases, including lymphatic filariasis.

Although people suffering from advanced lymphoedema cannot be cured, the symptoms can be eased through surgery and care. Sightsavers works with WASH (water, sanitation and hygiene) organisations to help households access clean water and facilities, so people can clean their affected limbs and care for their skin with clean water and soap. Symptoms can also be helped by elevating limbs and by wearing footwear. Hydrocele can be cured through surgery, transforming the lives of men affected.

A nurse helps a woman learn how to care for her swollen limb caused by lymphatic filariasis.

Caring for patients in Democratic Republic of Congo

An estimated 42 million people in DRC need treatment for lymphatic filariasis. Find out how Sightsavers is working to protect communities.

What we’re doing

Find out about other diseases we treat

Neglected tropical diseases

More about lymphatic filariasis

Sightsavers from the field

“Taking photos helps people to understand our problems”

People in Nigeria with diseases affecting the skin have shared their photos as part of a research project into how these conditions can be better managed.

May 2021
African Renaissance Monument is lit up in honour of World NTD Day.
Sightsavers from the field

World NTD Day 2021: highlights from around the world

On 30 January 2021, Sightsavers joined global celebrations to mark the fight against neglected tropical diseases.

February 2021
Illustration of a health worker helping a patient.

Researchers: See the people behind the numbers

Neglected tropical disease programmes need to focus on people, not just count disease prevalence, say Sightsavers researchers.

December 2020

Learn how we’re fighting disease