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Dr. Gilbet Burnham presents on Mectizan distribution

Controlling River Blindness: Achievements of a 15-Year
Public-Private Partnership

On 14 May 2004, the Johns Hopkins Bloomberg School of Public Health and Merck & Co., Inc. co-sponsored a symposium entitled "Controlling River Blindness: Achievements of a 15-Year Public-Private Partnership." The symposium took place in Baltimore, Maryland, USA at the Johns Hopkins Bloomberg School of Public Health and was well attended by students and public health professionals.

The symposium was held to commemorate the publication of a compendium of articles published in the March 2004 issue of Tropical Medicine and International Health (Volume 9, Issue 3, pp A1-A56). The articles are based on both original research and literature reviews to evaluate the Mectizan Donation Program (MDP) and the impact of Mectizan distribution on primary health care, economics, onchocercal morbidity, and public-private partnerships for health services/programs. The authors found the Mectizan Donation Program to be both successful and cost-effective and recommended that the public-private partnership developed as a result of the program serve as a model for others seeking to establish similar health programs.

Symposium participants

Dr. Björn Thylefors presented on "Eliminating onchocerciasis as a public-health problem", which described the evolution of onchocerciasis control and challenges for future control of the disease. Dr. Thylefors began by commenting on the present and future status of the Mectizan Donation Program, noting that currently, mass treatment is ongoing in 34 out of 35 endemic countries with more than 50 million treatments approved in 2003. Future challenges include reaching the ultimate treatment goal in Africa of greater than 90 million people per year, eliminating the disease in the Americas, continued monitoring and evaluation, and operational research to maintain effective programs.

Following Dr. Thylefors was a presentation given by Ms. Traci Phillips on the article "Mectizan Donation Program - evaluation of a public-private partnership." This study evaluated MDP's public-private partnership with other stakeholders in the control of onchocerciasis. The study methods included a survey of 25 individuals from 21 of MDP's partner organizations and semi-structured interviews with key informants consisting of experts highly experienced in onchocerciasis control. The evaluation focused on the benefits to partner organizations, costs of participation, elements of governance, and management functions. The study's objectives were: 1) to determine how long-term relationships were sustained among a diverse group of partners and 2) to determine whether the MDP partnership model can be applied to other public-private partnerships for public health. The study concluded that MDP has consistently shown good leadership and competency. Characteristics contributing to the success of the program included high-level commitment, goodwill established from the outset of the program, and clearly defined roles and relationships among partners.

Dr. Hugh Waters gave the next presentation on "Economic evaluation of Mectizan distribution", which was based on a review of published articles on the impact of Mectizan distribution on economic indicators. In the Onchocerciasis Control Program in West Africa (OCP), Mectizan distribution enhanced vector control as a way to eliminate onchocerciasis as a public health problem. Studies conducted in the OCP area show that labor productivity has been increased through the prevention of blindness and that arable land, once deserted because of the disease, has been re-populated after transmission of onchocerciasis was reduced. The fact that Mectizan is provided free of charge by Merck & Co., Inc. was cited as an important contribution to the positive economic impact of the program stating that "the economic value of Mectizan itself for 1 year is greater than the projected economic benefits of its distribution over a period of 20 years or more". The study concluded that development of an effective macrofilaricide would greatly enhance efforts to eliminate transmission of onchocerciasis; however, until that happens, the distribution of Mectizan is an economically viable and successful means to control the disease.

Following Dr. Waters was Dr. Gil Burnham who presented "Delivering Mectizan (ivermectin)." This article describes the evolution of Mectizan distribution and the strategies and tools developed to make mass distribution of the drug successful. Assessment of the populations at-risk to establish priority mass treatment areas was one of the challenges mentioned in the article. Originally, epidemiological data was collected using skin snips taken from individuals in infected communities that were microscopically examined for evidence of infection. This invasive method was later replaced by the examination of individuals for the presence of subcutaneous nodules associated with onchocercal infection. Prevalence within the community was determined to be one and one-half times the percentage of nodule carriers in the sample tested. The Rapid Epidemiological Mapping of Onchoerciasis (REMO) methodology uses epidemiological, entomological, and cartographical factors, such as the distance of communities from breeding sites, to map onchocerciasis endemicity. Today, most countries in Africa and have used REMO to identify onchocerciasis-endemic areas and to establish priority areas for mass treatment.

The next milestone in the delivery of Mectizan was the method of distribution within communities. Several of the first Non-governmental Development Organizations (NGDOs) that distributed Mectizan soon realized that involving communities in both the design of Mectizan distribution programs and the selection of community distributors may help achieve higher coverage. To address this issue, the Community-Directed Treatment with Ivermectin approach was developed and refined over time. The approach was established as the preferred method of mass distribution following a multi-country study conducted in 1995 by the World Health Organization Special Programme for Research and Training in Tropical Diseases in collaboration with the African Program for Onchocerciasis Control and the Onchocerciasis Control Program in West Africa. The study found that communities planning their own mass distribution programs achieved higher coverage than in communities where health workers planned the distribution. Furthermore, the approach was feasible and effective in a variety of countries and cultures.

The creation of a broad partnership, which includes: the Mectizan Donation Program, Merck & Co., Inc., the World Bank, the World Health Organization, Ministries of Health, and NGDOs has also contributed to the success of Mectizan mass treatment with partners working together to secure technical and financial support and to resolve operational issues. Future challenges faced by the partnership include maintaining commitment to the program by governments and communities in the face of declining blindness, maintaining donor interest in spite of other health priorities, and the potential for integrating Mectizan distribution with other health interventions.

The final presentation was given by Dr. James Tielsch on "Impact of ivermectin on illness and disability associated with onchocerciasis." This article reviews clinical trials on Mectizan treatment for onchocerciasis, investigations on the effects of Mectizan on skin and eye disease, and studies on the impact Mectizan treatment has had on blindness and disability associated with the disease. It is well-known that Mectizan is a safe and effective treatment for onchocerciasis that has shown significant impact on the prevalence of blindness and skin disease and on transmission of the disease in areas where distribution has been ongoing with high coverage. In addition, few ocular and systemic side effects of treatment are experienced even among individuals with heavy parasitic loads. During his presentation Dr. Tielsch pointed out that in addition to its clinical benefits, Mectizan appears to lead to a significant reduction in the reproductive capacity of adult worms, which contributes to the reduction of onchocerciasis transmission. He also noted that it is likely that the impact on disability adjusted life years (DALYs) associated with skin disease is similar to the impact on DALYs associated with ocular disease. This study also reviewed Mectizan's positive impact on other helminthic infections, which contributes to compliance in mass distribution programs. He concluded by noting that, although elimination of onchocerciasis is not feasible because of political, economic, and social constraints except in Latin America where foci are small and geographically contained, mass treatment has a substantial impact on onchocerciasis; and continuation of onchocerciasis control programs using Mectizan is needed to maintain the benefits already achieved.