What is elephantiasis?

Elephantiasis (which is also known as lymphatic filaraisis) is a mosquito-transmitted disease that is caused by parasitic worms and which damages the human lymph system.

The disease can cause severe and extensive swelling of the lower limbs (lymphedema), which can be accompanied by painful episodes of fever. People with lymphedema are prone to bacterial infections that can lead to a mobility-limiting condition where the skin thickens and hardens. In men, elephantiasis can also result in the swelling of the scrotum (hydrocele).

Elephantiasis affects the poorest communities, preventing individuals from living a productive working and social life, further trapping them in the cycle of poverty.

People affected by elephantiasis

36 million people are estimated to live with a chronic condition 893 million people were at risk of infection in 2018

Source: WHO data 2018

WHO NTD roadmap targets for elephantiasis

The World Health Organization’s roadmap on NTDs set out a comprehensive plan for the control, elimination and eradication of various neglected tropical diseases by 2020, including elephantiasis.

Elephantiasis target: Global elimination as a public health problem by 2020

Countries that have eliminated elephantiasis

16 countries have eliminated elephantiasis since 2012:

  • Maldives (2016)
  • Sri Lanka (2016)
  • Cambodia (2016)
  • Cook Islands (2016)
  • Niue (2016)
  • Vanuatu (2016)
  • Marshall Islands (2017)
  • Togo (2017)
  • Tonga (2017)
  • Thailand (2017)
  • Egypt (2018)
  • Palau (2018)
  • Vietnam (2018)
  • Wallis & Futuna (2018)
  • Yemen (2019)
  • Kiribati (2019)
  • Malawi (2020)

Mass drug administration progress for elephantiasis

People receiving preventive chemotherapy for elephantiasis

Since the London Declaration was signed in 2012 and partners committed to defeating neglected tropical diseases, the number of people receiving preventive chemotherapy for elephantiasis has increased considerably.


  • Data is provided by the World Health Organization
  • Photo: © GSK / Marcus Perkins