The 'River Blindness' Control Programmes Ocp and Apoc in Africa: A Critical Review
Asian Journal of WTO & International Health Law and Policy, Vol. 1, No. 2, pp. 253-276, September 2006
24 Pages Posted: 11 Oct 2007
Abstract
Onchocerciasis Control Programme in West Africa (OCP; 1974 - 2002) was one of the most successful large scale operations ever carried out in the field of vector transmitted diseases. It is also an example to demonstrate that a programme without any medical intervention was able to eradicate a disease, on a scale of several countries. This success was achieved first because of the feasibility of the eradication of the vector, but also because of the very well controlled activities and very precise data collected and processed almost daily as a continuous evaluation process. Moreover, the target being the eradication of flies, the OCP achieved two of the most important goals in the process: reduction of the flies' bites and the transmission of the disease. Flies bites are considered by affected populations (mostly agricultural workers) as the most disturbing aspect of the disease complex even more so than blindness.
Unfortunately, after roughly 30 years, there remains a doubt concerning the sustainability of these impressive results. The reason is that all around the OCP area, Simulium blackflies are ever present and since stopping the spraying of insecticides, flies are coming back to reinvade the areas of population settlement. During the first period of reinvasion, the flies are harmful even if non infective because of the disappearance of the disease in man. But African people are travellers, including those infected with O. volvulus. This could be enough to make the flies infective again after a few years.
The African Programme of Onchocerciasis Control (APOC; 1995-2010) was implemented in more than 20 countries all around the OCP original area. It was made possible after a drug, ivermectin, became available for public health use. APOC was created with a very different conception of control of river blindness. First, it was based not on the eradication of the vector of the disease, but on a very large scale distribution of ivermectin. The hundreds of millions of tablets needed are provided free of charge to all African countries involved in the programme for an indefinite period of time by the Merck Company Ltd.
The authors' opinion is that such a programme raises concerns, the most important being (1) a large scale action based on the good will of a community and weak national health services is not sustainable; (2) the programme is not really evaluated (except through the counting of tablets distributed); (3) it will stop as such in 2010 ; (4) it does not address the flies' nuisance at all which will lead to a lot of other problems, in particular regarding the population's compliance and cooperate with the programme and the national health services' motivation as well; (5) the efficacy of ivermectin at a very late stage of individual infection and disease will lead to partial and very unstable epidemiologic results. The more general point of fighting a vector transmitted disease through the large scale distribution of a drug is also discussed and compared with the situation of schistosomiasis for which a much more effective product than ivermectin for onchocerciasis has been available for decades and which has been effective only with accompanying environmental and behavioural measures.
Keywords: vector born disease, river blindness, onchocerciasi, control programmes, West Africa, WHO, World Bank
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