What is onchocerciasis

The disease is caused by an infection from a parasitic worm transmitted by blackflies. These flies breed in fast-flowing streams and rivers. The adult worms that are transmitted produce larvae that move to the skin, eyes and other organs. This can lead to debilitating itching, disfiguring skin conditions and sight loss (including irreversible blindness). With these conditions, onchocerciasis has an enormous impact on the lives of those infected by reducing their ability to work and study in school.

People affected by onchocerciasis

26 million people are infected with the onchocerciasis worm 184 million people are at risk of contracting onchocerciasis 99% of people infected live in sub-Saharan Africa

WHO NTD roadmap targets for onchocerciasis

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 onchocerciasis.

Onchocerciasis target: Elimination by 2020

  • Elimination in Latin America by 2015
  • Elimination in Yemen by 2015
  • Elimination in selected African countries 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.

Coverage and impact
Programme support
Drug requests filled
Overall progress

Countries that have eliminated onchocerciasis

4 countries have eliminated onchocerciasis since 2012:

  • Colombia (2013)
  • Ecuador (2014)
  • Mexico (2015)
  • Guatemala (2016)

Countries implementing preventive chemotherapy for onchocerciasis

People receiving preventive chemotherapy for onchocerciasis

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

The coverage percentage is lower than in previous years, partly because the total number of treatments required has increased with the addition of formerly untreated hypo-endemic areas to the treatment area.


  • Data is provided by the World Health Organization