Clinical manifestation of lymphatic filariasis

What is lymphatic filariasis?
Lymphatic filariasis is a parasitic disease. Three species of microscopic worms cause lymphatic filariasis. The adult parasitic worm lives in the lymph of humans. Lymphatic filariasis infects nearly 120 million people in 72 countries throughout the tropics and sub-tropics of Asia, Africa, the Western Pacific, and parts of the Caribbean and South America. Nematodes (roundworms) of the family Filariodidea cause this disease, and transmission is via the bite of mosquitoes.

How does Lymphatic filariasis spread?
Mosquitoes transmit lymphatic filariasis, it bites the person infected by a filarial worm, and microscopic worms enter from the infected host bloodstream and infect the mosquito. The mosquito, when it again bites a healthy individual, transfers the infection. The larvae enter the lymph of a healthy individual through the skin. An adult worm lives for 5-7 years and produces millions of worms by mating microfilariae into the bloodstream.

Clinical Manifestation of Lymphatic filariasis.
A few common symptoms are-;

• Inflammation
• Lymphedema
• Hydrocele
• Oedema

The following are the major clinical manifestations of lymphatic filariasis-:

1. Clinical manifestation – the microfilaraemia stage
   1. Acute manifestation – the fungal and bacterial infections play a role in ADL attacks.
   2. Secondary attack of fungus and bacteria leads to reticular lymphangitis.
   3. Acute Filarial Lymphangitis (AFL)
2. Chronic Manifestation – Lymphoedema of the Genitalia
   1. Lymphorrhea
   2. Chyluria
   3. Male genital disease
   4. Tropical Pulmonary Eosinophilia
   5. Filarial Granulomata
   6. Adenopathy

Diagnosis of Lymphatic filariasis

• A blood smear test helps detect larval roundworm W. bancrofti or B. malayi. The smear test is done at night when the larval population is high. The adult worm can be found in lymph if larvae are not detected in the bloodstream. In addition, antibodies produced in response to the worm can be used as a diagnostic tool.
• An antibody test determines the antibodies produced from filarial infestations in your body. Your body produces antibodies as a defense against infection. This examination can be done during the day.

Strategies and tools to control/eliminate lymphatic filariasis
The Strategies involve treatment at a mass level as well as individual level. For example, ivermectin + diethylcarbamazine (DEC) or the albendazole combination decreases blood microfilariae by 99%. A single dose of any drug, ivermectin or DEC, causes a 90% reduction in microfilariae. By preventing bacterial superinfection, lymph oedema and elephantiasis also get reduced. Nongovernmental development organization (CGDO), civil society organization (CSO), and GPELF are some organization that finds out how the disease spreads and marks out the zones of transmission.

Conclusion
The roundworm is a causative agent of lymphatic filariasis. Mosquitoes disease is a spreader of disease. This disease affects 120 million people and 72 countries. There are clinical, acute, and chronic manifestations of the disease, and elephantiasis, lymph oedema, and genital diseases are the most common ones. Various drug combinations are used to control and eliminate the disease. Government and non-government organizations, with the help of the public and private sectors, are working against the disease.

References

1. https://www.cdc.gov/parasites/lymphaticfilariasis/gen_info/faqs.html
2. https://doi.org/10.1142/9781848160866_0005
3. https://rarediseases.org/rare-diseases/filariasis/
4. https://www.who.int/news-room/fact-sheets/detail/lymphatic-filariasis
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2487030/
6. https://www.researchgate.net/publication/10862749_Lymphatic_filariasis_elimination_Progress_in_global_programme_development