2012 marks twenty five years since Merck announced the donation of Mectizan for river blindness control.
Before Mectizan, the only intervention for river blindness was vector control by larvaciding rivers where the black flies that cause the disease breed. The introduction of Mectizan in 1987 stimulated more interest in the disease and partners began working together on ways to get the drug out to the people who needed it.
Onchocerciasis
Mectizan distribution through non-governmental organization (NGO) partners in these countries scaled up over the years. Then in 2005, WHO, the World Bank, NGO partners, and the Mectizan Donation Program (MDP) worked together to form the African Program for Onchocerciasis Control (APOC) in 2005. APOC and other partners developed strategies to rapidly map the disease and distribute the drug using a community-based strategy. This strategy led to other successful health interventions at the community level for other neglected tropical diseases. Because of the communities, significant scale up and the ability to sustain treatment has been achieved.
In the Americas only 500,000 people in 6 countries were at-risk for river blindness. The Carter Center-sponsored Onchocerciasis Elimination Program for the America’s encouraged countries to achieve high (85%+) coverage with Mectizan. Today, transmission is suspected to be eliminated from 4 of the 6 endemic countries. In 2012, Colombia became the first country worldwide to apply to WHO for the certification of elimination of river blindness. Now, the only remaining areas with ongoing treatment are two Yanomami Indian populations in Venezuela and Brazil.
Lymphatic Filariasis (LF)
Mass drug administration (MDA) with Mectizan and albendazole (donated by Glaxo Smith Kline) for LF elimination has been ongoing since 2000 in countries where onchocerciasis and LF are co-endemic. The WHO recommends 5-8 years of treatment with high coverage, so there are already countries in the post-treatment surveillance phase for LF elimination where monitoring and evaluation is being conducted to ensure that transmission has been eliminated. Though some countries have finished MDA in Africa, others continue to scale up as they obtain the resources necessary for implementation. The 2020 goal to stop treatment for LF in Africa is still attainable if these countries can quickly scale up MDA in the next two years.
The Future
Over the next 25 years, we hope that LF will be eliminated and that the map of river blindness endemic countries will have shrunk to just a few areas where there are barriers such as civil conflict and co-endemicity with other diseases.
Twenty-five years ago, no one expected that this would be an option. No one could have anticipated that, through partnership and innovation, the end goal for river blindness would shift from control to elimination.
*Merck is known as MSD in some countries outside the US.