Onchocerciasis in West Africa after 2002: a challenge to take up

Abstract

Summary :Initially planned for a 20 year life time, the Onchocerciasis Control Programme in West Africa (OCP) will have finally continued its activities for nearly three decades (vector control alone from 1975 to 1989, then vector control and/or therapeutic treatment until 2002). Although onchocerciasis is no longer a problem of public health importance nor an obstacle to socioeconomic development in the OCP area, the control of this filariasis is not over because OCP never aimed at eradication, neither of the parasite (Onchocerca volvulus), nor of its vector (Simulium damnosum s.l.). In 2003, the eleven Participating countries of OCP will take over the responsibility of carrying out the residual activities of monitoring and the control of this disease. This mission is of great importance because any recrudescence of the transmission could lead in the long run to the reappearance of the clinical signs of onchocerciasis, if not its most serious manifestations. For epidemiological and operational reasons, and given the disparity in national health policies and infrastructures, the capacities of the countries to take over the residual activities of monitoring and control of onchocerciasis are very unequal. Indeed, the interventions to be carried out are very different from one country to another and the process of integrating the residual activities into the national health systems is not taking place at the same pace. This inequality among the countries vis-a-vis the challenges to be met does not, however, prejudge the epidemiological situation after 2002 whose evolution will also depend on the effectiveness of the provisions made before that date by OCP, then after 2002, by the Regional Office for Africa of the World Health Organization which is currently setting up a sub-regional multidisease surveillance centre.

Impact of ivermectin on illness and disability associated with onchocerciasis

“…Although countries endemic for onchocerciasis will become more involved in its control, the capacity of countries to assume monitoring and control activities is unequal. The disparity in health policies and infrastructures among these countries will influence the successful integration of control activities into national health systems (Hougard et al 2002). An early obstacle will be the maintenance of enthusiasm of the population during programme development.…”

Impact of ivermectin and vector control on onchocerciasis transmission in Togo: Assessing the empirical evidence on trends in infection and entomological indicators

“…In addition, few entomological surveys were performed after the closure of OCP and SIZ and it is therefore not known how the cessation of vector control has affected trends in ATP and ABR. When the 11 OCP countries, including Togo, took over the responsibility of carrying out the residual activities of monitoring and the control of onchocerciasis after closure of OCP and/or SIZ, the countries faced several challenges including lack of technical assets, financial resources, or skilled personnel [ 31 ]. The lack of entomological data makes it difficult to assess current transmission conditions and intensity.…”

Emergence de la fièvre catarrhale ovine dans le Bassin méditerranéen et surveillance entomologique en France

“…Dans les régions subtropicales et tempérées, la FCO se manifeste sous forme de flambées épizootiques plus ou moins régulières. Les vents du sud seraient à l'origine de la remontée de C. imicola en Méditerranée, cet insecte pouvant être diffusé passivement comme du « plancton aérien » sur de longues distances à l'instar d'autres espèces pour lesquelles de tels phénomènes ont été notés, comme Simulium damnosum sl, vecteur de l'onchocercose ou cécité des rivières en Afrique de l'Ouest (13). La pérennisation de populations locales survient à la faveur de conditions environnementales favorables.…”