Introduction

Elephantiasis, also known as lymphatic filariasis, is a neglected yet important tropical disease that can cause severe swelling and disfigurement of limbs, genitals or other body parts. Understanding its causes, transmission and prevention will provide key insight into controlling these diseases and supporting global elimination programmes.

Elephantiasis is a debilitating condition characterised by extreme swelling of body parts such as legs, arms, breasts or genitals and is usually caused by chronic obstruction of the lymphatic system. In many cases, it is a result of a parasitic infection transmitted by mosquitos although nonparasitic forms can also occur such as podoconiosis. This disease remains a significant health issue today, affecting millions worldwide and placing over 850 million people at risk. Additionally, elephantiasis imposes a heavy socioeconomic and psychological burden causing disability, loss of income and social stigma. Thus, understanding this disease is essential in guiding prevention strategies, improving early diagnosis and supporting global eradication efforts.  

What are the causes of this disease?

Elephantiasis is typically caused by a parasitic infection caused by thread – like filarial worms, in which there are three types:¹

• Wuchereria bancrofti – this is the most common type
• Brugia malayi
• Brugia timori

These parasites are transmitted to humans as larvae through the bite of infected mosquitos. The larvae survive in the bloodstream and fully mature into adult worms in the lymph system where they can live there for years, causing excessive damage and swelling. Inflammation, scarring and progressive obstruction can occur over several years as well as problems with draining fluid from the body; this persists even after the worms die.

In some cases, elephantiasis can occur without a parasitic cause, known as non-filarial elephantiasis such as podoconiosis. This is a condition linked to exposure to irritant minerals in volcanic soils, which can damage the lymphatic system. Other non-parasitic causes include repeated bacterial infections, tumours compressing lymphatic vessels and traumatic injury. In all cases, swelling is a result of a combination of lymphatic blockage, immune mediated inflammation and secondary infections that worsen tissue changes over time.

What are the types of elephantiasis?

There are generally two types of elephantiasis, each with distinct patterns of occurrence and appearance:

Filarial elephantiasis

This occurs in regions where lymphatic filariasis is endemic, especially in areas such as Africa, Southeast Asia, the Pacific Islands and South America. Swelling will typically begin asymmetrically and can affect one or more limbs as well as the genitals, particularly in men. A slow progression is usually seen, developing over years after an infection, with repeated episodes of fever and acute inflammation is typically seen.

Non – filarial elephantiasis

This is found in areas without parasite transmission such as the highland regions of Africa, Central America as well as parts of India. The most recognised cause is the long term exposure to irritant volcanic soils. Swelling will typically start at the feet before moving upwards and is usually bilateral. Other causes may be radiation, persistent inflammation, and repeated skin infections.³

What is the clinical presentation?

The symptoms of elephantiasis vary depending on the stage and whether it is caused by filarial or non-filarial factors. Most people do not present any symptoms, although this will still cause damage to their lymphatic system and kidneys. However, subtle signs will gradually develop.²

Early symptoms:

• Recurrent episodes of fever and tender lymph nodes, known as lymphadenitis
• Swelling of limbs or genitals
• Thickening of the skin

Chronic symptoms:

However, more permanent changes can be seen as the lymphatic damage worsen, and the fluid drainage becomes impaired.

• Persistent swelling, known as lymphoedema, of one or more limbs, scrotum, breasts
• Skin changes: thickening and hardening, callous texture due to repeated inflammation
• Reduced mobility of joints or limbs due to stiffness
• Secondary bacterial and fungal infections which may cause ulcers
• In men, fluid accumulation around the testes known as hydrocele

These symptoms can have a severe impact on daily life, causing difficulties in walking and working as well as other changes which can lead to significant emotional distress and social stigma.

What is the epidemiology of this disease?

This disease continues to be a major health challenge in many areas of the world, with the World Health Organisation (WHO) identifying this as part of the Neglected Tropical Diseases. More than 850 million people in 49 different countries are affected by this.

Filarial elephantiasis is more prevalent in South and Southeast Asia, with the countries with populations largest at risk being in India, Nigeria, Indonesia and Bangladesh.

Non-filarial elephantiasis is typically concentrated in highland areas with volcanic soils such as Ethiopia, Cameroon, Rwanda and Uganda.

What are risk factors?

Warm, humid climates typically support mosquito breeding, with volcanic soils for podoconiosis. Mosquito abundance will typically peak during rainy seasons which can increase the transmission risk. Poverty, poor sanitation, limited access to healthcare as well as walking barefoot in endemic soil regions can also contribute to increased cases of elephantiasis.

What are actions taken by WHO to prevent this? 

WHO had launched a global programme to eliminate and manage lymphatic filariasis, known as GPELF:

• Mass drug elimination: administer antiparasitic drugs such as albendazole combined with ivermectin.
• Vector control: the use of insecticide treated bed nets, indoor spraying as well as other techniques to reduce mosquito breeding sites
• Health education: ensure hygiene practices are in place such as footwear use

This programme had great results, as by 2023, 14 countries had successfully implemented these strategies, leading to substantial reductions in transmission of lymphatic filariasis.

How does this disease impact the public?

Elephantiasis has many devastating consequences on those affected, having a significant impact on their quality of life. 

Body deformities through tissue swelling and thickening can lead to reduced mobility and may result in permanent disability. Individuals may struggle with daily activities, leading to a loss of income earning opportunities as well as diminishing independence. This can result in an increased socioeconomic burden from lack of opportunities, increased healthcare costs and dependency burdens. Symptoms can also result in social stigma and discrimination, affecting the individual’s mental health in addition to managing their physical challenges of the disease.

Thus, elephantiasis can contribute to poverty cycles in already disadvantaged populations.

Summary

Elephantiasis is a neglected disease that continues to affect millions of people worldwide, particularly in low income countries. In most cases, it is caused by parasitic filarial infections yet non-parasitic factors may also contribute such as podoconiosis. This disease will typically lead to swelling, lymphoedema and can eventually result in disability. However, large scale control programmes such as WHO have made significant progress but continue to be of a high economic burden. Thus, increasing awareness and having efficient research is essential in reducing its economic burden and improving patient’s quality of life.

FAQs

Is this disease contagious?

No, it is not but the mosquitos that cause this disease can spread from person to person through vectors.

Can it be cured?

Antiparasitic drugs can kill roundworms, but they cannot reverse the swelling and tissue damage. However, prevention techniques such as ensuring good hygiene can reduce symptoms.

How is it diagnosed?

A doctor will do a blood test to confirm if roundworms are present in the bloodstream.

How can it be prevented?

• Use of mosquito nets
• Use of mosquito repellent
• Wear fully covered clothing
• Wear shoes in volcanic soil regions
• Maintain good hygiene