Lymphatic Filariasis (Elephantiasis)

Elephantiasis, or lymphatic filariasis, is an often overlooked tropical disease. It starts with filarial parasites transmission into humans via mosquitoes, and infection occurs. Infection is most commonly acquired in childhood, resulting in hidden lymphatic system damage.

Lymphoma, elephantiasis, and scrotal swelling are painful and unpleasant visible manifestations of the problem that occur later in life and lead to disability. These patients are physically disabled, but they also suffer social, mental, and financial losses, contributing to poverty and stigma. Fifteen million men with lymphoedema and over 25 million people with hydrocele were estimated to be affected by lymphatic filariasis at the global baseline. These serious chronic disease manifestations affect at least 36 million people. Lymphocytic filariasis can be eradicated, resulting in less suffering and a poverty reduction.

The Origin and Spread of the Disease

Adult worms lay their eggs in lymphatic vessels, disrupting the lymphatic system’s normal function. The worms have 6–8 years and produce millions of immature larvae that flow in the bloodstream. When mosquitoes bite an infected host, they ingest blood and become infected with microfilariae. Within the mosquito, microfilariae mature into infective larvae. When an infected mosquito bites a person, mature parasite larvae deposit on the skin, where they can enter the body. The larvae migrate to lymphatic vessels and mature into adult worms, continuing the transmission cycle. Various mosquitoes spread Lymphatic filariasis, including the Culex mosquito found in urban and semi-urban areas and the Anopheles mosquito.

Symptoms and Signs

Elephantiasis is a stage three level of lymphedema thickening the skin and tissues, the most common symptom of lymphatic filariasis. It was the first case of any mosquito-borne disease. Elephantiasis occurs when parasites become lodged in the human lymphatic system, obstructing lymph flow. 

Infections are most common in children. The skin condition caused by the disease is known as “elephantiasis tropica” (also known as “elephantiasis album”). Elephantiasis primarily affects body parts like lower limbs, and filarial worms of various species affect different body parts: Wuchereria bancrofti can cause hydrocele formation in the arms, legs, breasts, vulva, and scrotum, while Brugia timori rarely affects the genitals.

The infection of lymphatic filariasis can be asymptomatic, acute, or chronic. Most infections are asymptomatic, meaning they show no external signs of infection while still allowing the parasite to spread. Even if there are no symptoms, these infections can harm the lymphatic system and kidneys and alter the immune system. 

When lymphatic filariasis becomes chronic, it causes lymphoedema (tissue swelling), elephantiasis (skin/tissue thickening), and hydrocele in the limbs (scrotal swelling). Breast and genital organ involvement are common. Social stigma and poor mental health are common outcomes of such body deformities, as are lost income-earning opportunities and increased medical costs for patients and their caregivers. Isolation and poverty have enormous socioeconomic costs.

Diagnosis

The microfilariae are found via microscopic examination, the standard method for diagnosing active infection. This may be difficult because microfilariae only circulate in the blood at night in most parts of the world. As a result, the blood must be collected during the night. The blood sample is usually stained with Giemsa stain and is in the form of a thick smear. Antibodies to the disease can also be detected in the blood serum.

Prevention

The current prevention goal is to eradicate lymphatic filariasis, which is feasible given that the disease has no known animal reservoir. The World Health Organization states a recommendation for mass deworming, which involves treating entire groups of people at risk with a single annual dose of two drugs: albendazole in combination with either ivermectin or diethylcarbamazine citrate. Because the disease requires a human host, consistent treatment reduces microfilariae, which means the disease will not be transmitted, the adult worms will die out, and the cycle will be broken.

Treatment 

• Anthelmintic: Treatments for lymphatic filariasis vary depending on where the disease was acquired worldwide. Albendazole is used with ivermectin to treat the disease in Sub-Saharan Africa, whereas albendazole is used with diethylcarbamazine elsewhere. Geo-targeted treatments are part of a larger plan to eradicate lymphatic filariasis by 2020.
• Antibiotics: Doxycycline, an antibiotic, is also effective in treating lymphatic filariasis. Its disadvantages over anthelmintic drugs include the need for 4 to 6 weeks of treatment, the fact that it should not be used in young children or pregnant women, and the fact that it is photosensitizing, limiting its use for mass prevention. Elephantiasis parasites have a population of endosymbiotic bacteria called Wolbachia that live inside the worm. When the antibiotic kills the adult worms’ symbiotic bacteria, the nematode larvae no longer get the chemicals they need to develop, either killing them or preventing them from developing normally. Adult worms are permanently sterilised and die after 1 to 2 years instead of 10 to 14 years.

Conclusion

Lymphatic filariasis is a disease caused by filarial worms, parasitic worms. The majority of cases of the disease are asymptomatic. However, some people develop elephantiasis, a condition characterised by severe swelling in the arms, legs, breasts, or genitals. In addition, the skin may thicken, and the condition may become painful. Physical changes can negatively impact a person’s social and economic situation. Mass deworming, or treating entire groups of people infected with the disease, is one way to prevent it. Every year, this is done for about six years to eradicate the disease from a population completely.