A defining moment in the fight against river blindness came when Merck pledged to provide ivermectin, packaged as Mectizan, for as long as it was needed. Mectizan was delivered through community driven programmes where community volunteers and leaders carried out the distribution together with health education and community engagement activities. Community volunteers and leaders were largely responsible for sustaining the programme for over a decade, working alongside Ministry of Health staff to deliver health interventions even in remote areas plagued by political insecurity and armed conflict.
Mectizan treatments were stopped in 2008, after which three years of post-treatment surveillance were required by the WHO to assess transmission of the parasite. WHO then sent a team of international experts to the country to verify the elimination of the disease.
On April 5, 2013, WHO Director-General Dr. Margaret Chan provided Colombia with official notification that WHO verified elimination of the disease. The WHO is the only organization that can officially recognize the elimination of a disease. This also makes Colombia the first country in the Americas to eliminate river blindness.
When the Onchocerciasis Elimination Program for the Americas (OEPA) program was launched in 1993, an estimated 500,000 people in the Americas were at risk of the disease in six countries: Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela. Today, as the result of highly successful national programmes, transmission of this NTD has been broken in 96 percent of the region:
- Mexico and Guatemala, formerly the region's two most endemic countries, have interrupted transmission of river blindness, halted Mectizan treatment and begun their post-treatment surveillance.
- Ecuador, having completed its three years of post-treatment surveillance, has filed a request to WHO for a verification team visit.
- Transmission of the disease persists only in the hard-to-reach border area between Venezuela and Brazil in the Amazon rainforest where new villages of the indigenous Yanomani people were recently found.
Today, as the result of highly successful national programmes, Colombia also serves as a model for Africa, where 99% of onchocerciasis cases occur and where over 120 million people are at risk of contracting the disease. Uganda and Sudan have interrupted transmission, and eight more African countries are working towards elimination.