Let us talk about Lymphatic filariasis

I watched a documentary last weekend about lymphatic filariasis and that it is indeed still in existence among the neglected tropical diseases. Kindly use your column to enlighten us on the disease. Henry V. Thanks Henry for your question. According to the World Health Organization (WHO), Lymphatic filariasis, commonly known as elephantiasis, is a painful and […]

I watched a documentary last weekend about lymphatic filariasis and that it is indeed still in existence among the neglected tropical diseases. Kindly use your column to enlighten us on the disease.

Henry V.

Thanks Henry for your question. According to the World Health Organization (WHO), Lymphatic filariasis, commonly known as elephantiasis, is a painful and profoundly disfiguring disease. In communities where filariasis is transmitted, all ages are affected. While the infection may be acquired during childhood its visible manifestations may occur later in life, causing temporary or permanent disability.

Filarial infection can cause a variety of clinical manifestations, including the following:

• Lymphoedema of the limbs.
• Genital disease (hydrocele, chylocele, and swelling of the scrotum and penis).
• Recurrent acute attacks, which are extremely painful and are accompanied by fever.
• The vast majority of infected people are asymptomatic, but virtually all of them have subclinical lymphatic damage and as many as 40% have kidney damage, with proteinuria and haematuria.

What are the causes?

• Lymphatic filariasis (LF) is caused by infection with threadlike worms called nematodes of the family Filarioidea: 90% of infections are caused by Wuchereria bancrofti and the remainder by Brugia specie.
• Humans are the exclusive host of infection with W. bancrofti. Although certain strains of B. malayi can also infect some animal species (felines and monkeys), the life cycle in these animals is perceived as epidemiologically distinct from that in humans.

How it is transmitted?

• Adult male and female worms lodge in the lymphatics. Fecund females release larvae (microfilaria) which periodically circulate in the blood. Microfilaria circulating in the blood can be ingested by feeding mosquito vectors. The mosquitoes can then spread infective larvae to new hosts when feeding.
• The major vectors of W. bancrofti are mosquitoes of the genus Culex (in urban and semi-urban areas), Anopheles (in rural areas of Africa and elsewhere) and Aedes (in islands of the Pacific).
• The parasites of B. malayi are transmitted by various mosquito species of the genus Mansonia.
• Transmission in a community is influenced by the number of infected persons (prevalence), the density of microfilaria in the blood of infected persons, the density of vector mosquitoes.

How is it diagnosed?

• Circulating microfilariae can be detected by examining thick smears (20–60 µl) of finger-prick blood.
• The Alere Filariasis Test Strip (FTS) is a rapid diagnostic test recommended for mapping, monitoring and transmission assessment surveys (TAS).

Treatment and prevention

1. 1. The primary goal of treating affected communities is to eliminate microfilariae from the blood of infected individuals in order to interrupt transmission of infection by mosquitoes.
2. 2. Secondary prevention includes simple hygiene measures, such as basic skin care and exercise.
3. 3. For management of hydrocoele, surgery may be appropriate.
4. 4. mTertiary prevention includes psychological and socioeconomic support for people with disabling conditions to ensure that they have equal access to rehabilitation services and opportunities for health, education and income.
5. 5. Avoidance of mosquito bites through personal protection measures or community-level vector control is the best option to prevent lymphatic filariasis