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.

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.

120 million

people worldwide are affected by lymphatic filariasis

47 countries

need preventative treatment for the disease

863 million

people are currently at risk of contracting it

Source: World Health Organization

How is lymphatic filariasis treated?

A boy holds a tablet used to treat neglected tropical diseases.

Medication

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

A close-up of a health worker helping a patient to wash their leg, which has a large sore on it. The health worker is wearing gloves.

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

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 is not co-endemic, lymphatic filariasis is treated using diethylcarbamazine, produced by Eisai, and albendazole tablets, donated by GlaxoSmithKline.

In 2023, we provided more than 16 million treatments for LF worldwide. We also trained more than 100,000 local volunteers to distribute medication via mass drug administration to treat a range of neglected tropical diseases, including lymphatic filariasis.

Although people with 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 limbs and care for their skin. Symptoms can also be helped by elevating limbs and by wearing footwear. Hydrocele can be cured through surgery, transforming the lives of men affected.

Find out about other diseases we treat

Neglected tropical diseases

More about lymphatic filariasis

Mzowele drinks water after taking medication for lymphatic filariasis.

Stories / Fighting disease /

As the world celebrates the 12 billionth treatment to protect people from lymphatic filariasis, we reflect on our collaborative journey towards eliminating the disease across Africa.

Sabane sits under a tree after successful surgery to treat hydrocele, caused by lymphatic filariasis.

Stories / Fighting disease /

In Burkina Faso, the ARISE II programme is helping to transform the lives of thousands of people who are suffering from lymphatic filariasis.

Volunteer Moses measures a woman's height to see how much medication she needs to protect her from river blindness.

Stories / Fighting disease /

Sightsavers’ Khadijah Bello travelled across north-central Nigeria to see how our programmes are fast-tracking the elimination of neglected tropical diseases.

Nine-year-old Khadijah at school with her friend after successful cataract surgery. They're sitting at a desk writing on a shared piece of paper, wearing their blue school uniforms.

Nine-year-old Khadijah (right) is no longer at risk of going blind.

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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.

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