The Onchocerciasis Control Program

In December 2002 the West Africa Onchocerciasis Control Program (OCP) closed after 28 years. OCP was one of the great successes in the relatively short history of public health. Initiated in 1968, the program started in 1974 as a joint effort of the World Bank, the United Nations Development Program (UNDP), the Food and Agricultural Organization of the United Nations (FAO), the World Health Organization (WHO), host country governments and a total of 22 donor countries and organizations. Initially, the program covered 7 countries (Benin, Burkina Faso, Côte d'Ivoire, Ghana, Mali, Niger and Togo). In 1986, it was extended to Guinea (Conakry), Guinea-Bissau, Senegal and Sierra Leone. The program focused on countries where the impact of onchocerciasis was the most severe and where the ecological conditions allowed for eradication of the vector for an extended period of time. At the time of creation of the OCP, no medications were available to fight the parasite in either its adult or juvenile (microfilarial) stage that did not have severe side effects, and therefore, no pharmaceutical based interventions were possible. Consequently, the program had to focus on eradicating the vector (the blackfly) for a long enough period of time to break the transmission cycle - approximately 14 years. The technique used for this was aerial larviciding of the breeding sites in the rivers.

In 1987 the drug Mectizan® (also known by its generic name ivermectin) became available for use in combating the disease. It destroys the juvenile stage (microfilaricide), but not the adult worm. Merck & Co., Inc., manufacturers of the drug, have committed themselves to providing it in necessary doses for treatment of onchocerciasis free of cost "for as long as needed to as many as needed". This important addition to the fight against onchocerciasis allowed the OCP to combine Mectizan® distribution with vector control where appropriate. Since Mectizan® does not kill the adult worm, annual treatment is needed for an extended period of time (approximately 20 years) to prevent the return of the disease.