
Worming into the body —
120 million people worldwide are infected with the parasitic disease Lymphatic filariasis, commonly known as elephantiasis, and 1.4 billion people are at risk of becoming infected in 72 countries globally. The majority of disease is caused by the parasitic worm Wuchereria Bancrofti -- responsible for 90% of cases.

The bite behind the bulge —
Lymphatic filariasis is transmitted by different types of mosquitoes including Culex, Aedes and Anopheles mosquitoes. The young larvael forms are picked up when mosquitoes feed on human blood. Once inside the mosquito the parasites migrate to the gut of the insect where they develop and move to the head of the mosquito ready to penetrate through human skin when the insect next feeds on a human..

Inflated limbs —
The majority of infections remain asymptomatic but 40 million people worldwide have developed clinical signs of the diseases, such as lymphoedema, causing fluid retention and the characteristic swelling of the legs and feet to enormous proportions. The country with the greatest number at risk of infection is India. There is no treatment or vaccine.

The battle in India —
The swelling of body parts is caused by adults forms of parasitic filarial worms, which form nests in the lymph vessels and lymph nodes of the body causing swelling. India has the greatest burden of lymphatic filariasis in the world and a new national campaign was launched in December 2014 to deliver 400 million tablets to communities at-risk of infection.

Drug control —
The main strategy used globally to control lymphatic filariasis is the widespread distribution of the de-worming drugs diethylcarbamazine (DEC) and albendazole, to prevent people transmitting the disease once infected, known as mass drug administration (MDA). Whilst DEC kills some adult forms of the worm, the drugs mainly control transmission by killing the young worms found in the blood stream.

Childhood infection —
Infections usually occur during childhood and may take 8 to 10 years to cause symptoms. The majority of infections remain asymptomatic but can cause hidden damage to the lymphatic system. India has the longest running control programme in the world and hoped to reach elimination in 2015.

Managing morbidity —
When symptoms, such as the swelling caused by lymphoedema arise, there is no treatment. The only option for patients is to manage the symptoms by draining fluid where possible or else keep limbs and wounds clean through regular washing.