What is lymphatic filariasis?

Lymphatic filariasis (LF) is a mosquito-transmitted disease caused by parasitic worms that damage the human-lymph system.

It 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 (elephantiasis). In men, lymphatic filariasis can also result in the swelling of the scrotum (hydrocele).

Lymphatic filariasis 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 lymphatic filariasis

67 million people are infected by lymphatic filariasis 36 million people are living with hydrocele and lymphedema

WHO NTD roadmap targets for lymphatic filariasis

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 lymphatic filariasis.

Lymphatic filariasis target: Global elimination as a public health problem by 2020

Progress and scorecard from the 5th progress report

Since 2012, we have monitored progress annually for each disease. This information is from the 5th progress report of the London Declaration published in 2017.

Lymphatic filariasis programmes globally have had a significant impact. 20 countries and 499 million people were no longer in need of MDA as of 2016, and ten countries have now eliminated the disease as a public health problem. 92% of evaluation units assessed reached the threshold and no longer need treatment.

Coverage and impact
Programme support
Drug requests filled
Overall progress

Countries that have eliminated lymphatic filariasis

10 countries have eliminated lymphatic filariasis 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)

Mass drug administration progress for lymphatic filariasis

62 countries are endemic for lymphatic filariasis

People receiving preventive chemotherapy for lymphatic filariasis

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


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