Etude des politiques relatives aux stratégies de gestion de la chimiorésistance dans le cadre de la lutte contre la trypanosomose en Afrique de l'Ouest: cas du Mali

Discussion sur l’etude des politiques relatives aux stratégies de gestion de la chimiorésistance dans le cadre de la lutte contre la trypanosomose en Afrique de l’Ouest, Mali. Le projet a pour objectif d’assurer l’efficacité des trypanocides comme une composante effective des strategies intégrées et améliorées de contrôle de Ia trypanosomose animale dans Ia region ouest-africaine. Pour atteindre cet objectif, des organisations nationales de recherche et de developpement, des institutions internationales et régionales de recherche, et des universités allemandes travaillent en partenariat afin de développer aux niveaux local et regional des strategies de reduction de risque de Ia chimiorésistance. L’accent est mis principalement sur l‘information et des supports techniques aux paysans, aux prestataires de service en sante animale, aux vétérinaires professionnels et aux décideurs politiques. Les informations et supports techniques ont pour but de promouvoir Ia lutte intégrée et l’utilisation rationnelle des trypanocides afin de réduire les risques a long terme de Ia chimiorésistance sans compromettre Ia capacité des éleveurs a pouvoir protéger leurs animaux contre les effets néfastes de la trypanosomose animale. Le projet est réalisé au Burkina Faso, au Mali et en Guinée par l’lnstitut International de Recherche sur l’Elevage (lLRl) en collaboration avec d’autres organisations. Des approaches de solutions sont alors proposees de maniere a apporter une solution durable au phenomene de la chimioresistance

Best-bet integrated strategies for containing drug-resistant trypanosomes in cattle

Background African animal trypanosomosis is a major constraint to the rearing of productive livestock in the sub-humid Sudan-Sahel zone of West Africa where cotton is grown. Trypanosomosis is mainly controlled using trypanocidal drugs, but the effective use of drugs is threatened by the development of widespread resistance. This study tested integrated best-bet strategies for containment and/ or reversal of trypanocide resistance in villages in south-east Mali where resistance has been reported. Methods Four sentinel villages each from an intervention area (along the road from Mali to Burkina Faso) and a control area (along the road from Mali to Côte d’Ivoire) were selected for the study. Tsetse control was based on deltamethrin-treated stationary attractive devices and targeted cattle spraying between March 2008 and November 2009. Trypanosome-positive cattle were selectively treated with 3.5 mg/kg diminazene aceturate. Strategic helminth control using 10 mg/kg albendazole was also undertaken. During the intervention, tsetse densities along drainage lines, trypanosome infections and faecal egg counts in risk cattle (3 to 12 months of age) were monitored. Results Catch reductions of 66.5 % in Glossina palpalis gambiensis and 90 % in G. tachinoides were observed in the intervention area. Trypanosome prevalence was significantly (p < 0.05) lower in the intervention area (2.3 %; 1.3-3.6 %) compared to the control area (17.3 %; 14.8-20.1 %). Albendazole treatment resulted in a faecal egg count reduction of 55.6 % and reduced trypanosome infection risk (2.9 times lower than in the placebo group) although not significantly (p > 0.05). Further studies are required before confirming the existence of albendazole resistant strongyles in the study area. Conclusion Integration of best-bet strategies in areas of multiple drug- resistance is expected to reduce trypanosome infection risk thus contributing to containment of trypanocidal drug resistance. Integrated best-bet strategies could therefore be considered a viable trypanosomosis control option especially in areas where multiple drug-resistance has been reported

African bovine trypanosomiasis: the problem of drug resistance

The three trypanocides used to control tsetse-transmitted trypanosomiasis in domestic animals in Africa have been in use for over 40 years and, not surprisingly, resistance of trypanosomes to these drugs has emerged. Because of the relatively limited market in Africa and the high costs of developing and licensing new drugs, international pharmaceutical companies have shown little interest in the development of new trypanocides for use in either animals or humans. Therefore, the current challenge is to achieve optimal use of the relatively old existing drugs, and it is in this context that the problem of drug resistance has to be quantified--as discussed here by Stanny Geerts, Peter Holmes, Oumar Diall and Mark Eisler