Lymphatic Filariasis

Tokelau: For Specific Travellers

Lymphatic Filariasis


Lymphatic Filariasis, also known as Elephantiasis, is a parasitic infection caused by the Wuchereria bancrofti, Brugia malayi, and Brugia timori nematode worms transmitted to humans through the bite of infected Aedes, Culex, Anopheles, and Mansonia mosquitoes. The disease targets the body's lymphatic system. The infective microscopic larvae (microfilariae) develop in the vector mosquitoes and are injected into humans through a blood meal. In the human host, they reproduce and mature over a period of one year and live in the body for approximately 4 to 6 years. The larvae hatched in humans are ingested by feeding mosquitoes who pass the infection on to another person, continuing the infectious cycle. Lymphatic Filariasis is a Neglected Tropical Disease (NTD)*.

* Neglected Tropical Diseases are chronic infections that are typically endemic in low income countries. They prevent affected adults and children from going to school, working, or fully participating in community life, contributing to stigma and the cycle of poverty.


Lymphatic Filariasis is present in Africa, Central and South America, South Asia, and the Pacific Islands. Long-term travellers, persons on work assignments like humanitarian workers, missionaries, and military personnel staying in endemic areas are at risk.


The majority of cases are asymptomatic – persons do not exhibit symptoms – although the worms can damage kidneys and lymph nodes over a long period of time without signs of illness. A severe infection, which may not show up for years, causes swelling in the genitals, breasts, arms and legs and may progress to lung disease. Treatment includes taking the anthelmintic drugs.


  • Use a repellent containing 20%-30% DEET or 20% Picaridin on exposed skin. Re-apply according to manufacturer's directions.
  • Wear neutral-coloured (beige, light grey) clothing. If possible, wear long-sleeved, breathable garments.
  • If available, pre-soak or spray outer layer clothing and gear with permethrin.
  • Get rid of water containers around dwellings and ensure that door and window screens work properly.
  • Apply sunscreen first followed by the repellent (preferably 20 minutes later).
  • For more details, see IAMAT's insect bite prevention.

There is no preventive medication or vaccine against Lymphatic Filariasis.

Lymphatic Filariasis nematode images, life cycle, and distribution maps: Infection Landscapes

Information last updated: February 23, 2021. 

  • Agosti J. Filarial Diseases. In: Jong, E; Stevens, D, eds. Netter’s Infectious Diseases. New York: Saunders Elsevier; 2012: 504-515.
  • Fox L, King C. Lymphatic Filariasis. In: McGill, A; Ryan, E; Hill, D; Solomon, T, eds. Hunter's Tropical Medicine and Emerging Infectious Diseases. 9th ed. New York: Saunders Elsevier; 2013: 815-822.
  • Wertheim, Heiman; Horby, Peter; Woodall, John, eds. Atlas of Human Infectious Diseases. Oxford: Wiley-Blackwell; 2012. 273 p.
  • Centers for Disease Control and Prevention: Lymphatic Filariasis
  • World Health Organization: Lymphatic Filariasis Fact Sheet No. 102