Lymphatic Filariasis



Lymphatic Filariasis due to Wuchereria bancrofti is the only type of lymphatic filariasis present in the Americas.
The infection is transmitted by infected mosquitoes and is associated with acute and chronic symptoms that can lead to disfigurement and consequently to social exclusion and stigma.

Measures are being taken to eliminate lymphatic filariasis as a public health problem from the Americas. The main pillar of the strategy is the massive annual distribution of two anthelmintic medications, diethylcarbamazine, and albendazole, to all people living in endemic areas for five years, or three medications, the two previous plus ivermectin, for two years.

Key facts
Fact sheet
  • Lymphatic filariasis, often known as elephantiasis, is a human infection that is caused by the transmission of parasites called filarias through mosquitoes, including those of the genus Culex, which is widespread in urban and semi-urban areas.
  • Mosquitoes become infected with microfilariae by ingesting blood when an infected carrier is bitten. The microfilariae mature in the mosquito and become infectious larvae. When infected mosquitoes bite people, mature parasite larvae settle on the skin, from where they can penetrate the body.
  • Lymphatic filariasis adopts asymptomatic, acute and chronic forms. Most infections are asymptomatic and have no external signs. Despite this they damage the lymphatic system and the kidneys and alter the immune system. The painful and very disfiguring manifestations of the disease, lymphedema, elephantiasis and scrotal inflammation appear later and can cause rejection and social stigma, with the consequent loss of self-esteem and decreased job opportunities for those affected, and therefore, affected their economic and social situation.
  • The disease can be eliminated in the Americas with the simultaneous massive administration of two anthelmintic drugs, diethylcarbamazine and albendazole (DA) to all people living in endemic areas for 5 years or three medications, the previous two plus ivermectin (IDA), for 2 years.
  • In places where the disease is endemic, the use of mosquito nets is recommended in the windows and doors of homes and on beds, the elimination of mosquito breeding sites and the application of insecticides in open latrines.
PAHO Response
  • Lymphatic filariasis is a disease considered "potentially eradicable".
  • In 1997 the World Health Assembly passed Resolution WHA50.29 on the elimination of lymphatic filariasis as a public health problem. 
  • In September 2016, through Resolution CD55.R9, the PAHO Directing Council approved the Action Plan for the Elimination of Neglected Infectious Diseases and Post-Elimination Measures 2016-2022, one of whose goals is the elimination of lymphatic filariasis in the Americas by 2022.
  • In May 2013, the World Health Assembly adopted the Resolution WHA 66.12, and reaffirmed the goals of 2020 for 17 neglected tropical diseases, including Lymphatic Filariasis, by 2020. 
  • PAHO / WHO collaborates with endemic countries to obtain donations of drugs, diagnostic tests, and other supplies necessary to interrupt and eliminate transmission. PAHO also supports countries in the design and implementation of baseline epidemiological and impact assessment studies. Also, contributes to the planning, implementation, and evaluation of mass drug administration campaigns. PAHO / WHO coordinates these actions through the Regional Program of Neglected Infectious Diseases and supports endemic countries to obtain validation of the elimination of lymphatic filariasis as a public health problem.