Severe Disfigurement and Disability
Lymphatic filariasis (referred to as LF and also known as elephantiasis) is a mosquito-borne disease that is caused by parasitic filarial nematodes. Though infection usually is acquired in childhood, the grotesquely disfiguring effects of LF is greatest in adults. LF can lead to severe disfigurement and disability due to swelling from fluid build-up caused by improper functioning of the lymphatic system.
It is estimated that more than 1.3 billion people in 72 countries worldwide are at risk of the disease, and 30% of them live in Africa. Of the over 120 million people infected with LF, 40 million are incapacitated or disfigured by the disease.
In endemic communities, it is estimated that 10-50% of men and up to 10% of women can be infected with LF. Due to the psychological and social stigma associated with LF, people living with the disease have a poor quality of life and are often unable to work, provide for their families or be active members of their communities.
Transmission cycle and symptoms:
When a mosquito with infective stage larvae bites a person, parasites enter the body and migrate to the lymphatic vessels. In the lymphatic system, the larvae develop into adult worms. Infection causes improper functioning of the lymph system, which leads to fluid build-up and swelling (lymphedema).
LF can cause a broad range of clinical manifestations, ranging from people with no evident symptoms to those with lymphedema and severe disfigurement of the extremities and genitalia. The condition where individuals have crippling and grotesquely swollen or enlarged limbs and the skin has thickened is called elephantiasis. Legs can be so severely swollen that individuals are unable to walk.
Did you know...
Elephantiasis is a syndrome most often caused by an obstruction of the lymphatic vessels, which results in extreme swelling of the skin and tissues, typically in the lower trunk and body. It primarily affects the legs and genitals, resulting in baggy, thickened and ulcerated skin, along with fever and chills.
Elephantiasis can be very painful and uncomfortable and reduces the sufferer’s ability to lead a normal life. A serious complication of elephantiasis can be obstructed blood vessels, which limit blood supply and cause the skin to become infected and gangrenous.
In men, lymphedema of the genitalia usually involves swelling of the scrotum, often to the size of a watermelon making it very painful and difficult to walk. In women, the condition may cause swelling to occur in one or both breasts. Internal damage to the kidneys and lymphatic system is also caused by the circulating microfilariae.
Diagnosis and treatment:
Diagnosis of LF requires a detailed epidemiological history, clinical findings and laboratory tests. Though not all individuals have microfilariae circulating in their blood, laboratory examination for microfilariae in nocturnal blood is used to determine whether communities require mass treatment. Once diagnosed, fast-acting, safe and effective drugs are available to treat LF (DEC and albendazole if onchocerciasis is not co-endemic or ivermectine and albendazole if onchocerciasis is co-endemic).
The current treatment strategy for LF is based on studies that have shown that infection transmission can be broken if annual distribution of combined drug therapy is maintained for approximately five to seven years. DEC is donated by Eisai Co., and albendazole and ivermectine are donated by GlaxoSmithKline and Merck & Co. respectively. In 2000, the WHO launched the Global Program to Eliminate Lymphatic Filariasis (GPELF) in response to World Health Assembly Resolution 50.29, calling for elimination of LF as a public health problem by 2020.