Growth, Challenges, and Solutions over 25 Years of Mectizan and the Impact on Onchocerciasis Control

History and BackgroundThe Mectizan Donation Program (MDP) was established in 1987 to oversee Merck's donation of Mectizan (ivermectin, MSD) for the control of onchocerciasis (river blindness) worldwide [1].This was accelerated and expanded when Merck made a groundbreaking announcement in 1987: it would donate ivermectin, completely free of charge, as much as needed and for as long as needed, for the elimination of river blindness as a public health problem in all endemic countries.P0rior to the donation of Mectizan, vector control was the only strategy used to control the disease.The World Health Organization's Onchocerciasis Control Program (OCP) led the effort for 25 years, which resulted in very low endemicity in some West African countries.When Mectizan was donated, the implementation of mass drug administration (MDA) emerged as the primary strategy to control and eliminate onchocerciasis.The success of MDA led to the concept that drugs for other neglected tropical diseases (NTDS) could be distributed using the same strategy.When MDP began, there was no distribution mechanism to reach the entire population at risk for onchocerciasis, particularly those living in remote, rural areas with poor health infrastructures.Merck approached a number of United Nations and international development agencies to request help distributing the drug, but because of lack of an established model, none came forward to facilitate distribution of the drug [2].Determined to get the drug to the people who needed it, Merck established an independent program (MDP) and expert committee to develop a distribution mechanism to ensure the drug was distributed in a medically responsible manner with thorough supervision and monitoring [3].The Mectizan Expert Committee (MEC) is made up of individuals with a broad range of expertise in global health, tropical diseases, entomology, parasitology, and disease control.The MEC meets twice-yearly and includes participation by WHO Headquarters, WHO Africa Regional Office (AFRO), the African Program for Onchocerciasis Control (APOC), the Onchocerciasis Elimination Program for the Americas (OEPA), the World Bank, and the Centers for Disease Control and Prevention (CDC).The Onchocerciasis Control Programme (OCP) in West Africa began coordinating Mectizan distribution in some of the highly endemic areas for onchocercal blindness, while non-governmental development organizations (NGDOs) worked with Ministries of Health to cover the remaining areas of Africa.As mapping activities expanded, showing the real extent of the disease, it was clear that NGDOs and Ministries of Health did not have the resources to scale up as required.As a result, the Ministries and NGDOs, together with support from WHO and