Key facts

  • Globally, it is estimated that there are 18 million people infected and 270,000 blinded by onchocerciasis. It is one of the leading causes of blindness in many African countries (mainly in West Africa and Central Africa), but is also present in Yemen and in Latin America, specifically in Brazil and Venezuela which constitute Yanonami's area.  
  • In the Region of the Americas, Onchocerciasis transmission has been interrupted or eliminated in 11 out of the 13 foci. As a result of the regional initiative, only 20,495 people need treatment -every 3 or 6 months- in indigenous population Yanomami, located in the Amazon area.
  • Colombia was the first country in the world to receive the verification of the elimination of onchocerciasis in 2013, followed by Ecuador in 2014, Mexico in 2015, and Guatemala in 2016. It is estimated that Brazil and Venezuela will request WHO the verification by 2020 to 2030.
  • Since 1995, new cases of onchocerciasis blindness have not been reported in the Americas.
  • The minimum coverage of biannual mass treatment with Ivermectin (Mectizan®) in the 13 foci in the Region was achieved in 2002 and has been maintained since then.
  • Ivermectin has been donated in sustained constantly to the countries that require it by Mectizan® Donation Program.  
  • The Yanomami area in the Amazon Region, shared by Brazil and Venezuela, is considered as the greatest challenge for completing the regional interruption of transmission, for which the implementation of a border agreement of binational cooperation is urged.

What is onchocerciasis?

Onchocerciasis is a disease produced by the parasite Onchocerca volvulus, which is transmitted to humans by black flies. This disease also called river blindness because the black flies' larvae reproduce in rivers and streams with rapid water flow. The transmission to human is by repeated exposure to infected insect bites.  Symptoms include severe itching, disfiguring skin conditions, and visual impairment, including permanent blindness.

PAHO/WHO's response

  • In 1994, the World Health Assembly adopted Resolution WHA47.32 that emphasizes the need for the mass distribution of Ivermectin for onchocerciasis elimination; in addition to develop and disseminate the epidemiological methods for onchocerciasis evaluation and/or mapping in endemic countries.
  • In 2003, 2006, and 2009, the World Health Assembly adopted resolutions WHA56.26, WHA59.25, WHA62.1, respectively, whose objectives are to eliminate the new cases of blindness and avoidable visual disability, such as the morbidity caused by onchocerciasis.  
  • In 2008, the Directing Council of PAHO/WHO adopted Resolution CD48.R12 that established the objective of eliminating morbidity and interrupting onchocerciasis transmission by 2012. These goals were ratified through Resolution CD49.R19  , 2009 that encompasses all the neglected infectious diseases. In 2013, the Organization of American States-OAS approved Resolution AG/RES.2810(XLIII-O/13) in support of PAHO/WHO Resolution CD49.R19.
  • In 2013, the World Health Assembly approved Resolution WHA62.12 urging Member States to implement interventions against neglected tropical diseases (including onchocerciasis), to reach the targets as set out in WHO's roadmap for these diseases.
  • In 2016, the Directing Council of PAHO/WHO approved resolution CD55.R9, which establishes a plan for the elimination of neglected infectious diseases, including onchocerciasis.
  • PAHO/WHO  is a strategic partner of the Onchocerciasis Elimination Program for the Americas (OEPA), a regional initiative sponsored by The Carter Center that is in charge of technical operations and coordination of a multinational coalition of agencies, including the six endemic countries in the Americas, Center for Disease Control and Prevention (CDC),  United States Agency for International Development (USAID) the Mectizan® Donation Program, and other associates whose objectives are to interrupt the transmission, eliminate morbidity of river blindness and eliminate its transmission.

Updated: August 2017