[Influence of social perceptions and practices on the use of bednets in the malaria control programme in Ivory Coast (West Africa)]. / Representations sociales et pratiques liées à l'utilisation des moustiquaires dans la lutte contre le paludisme en Côte d'Ivoire (Afrique de l'Ouest).

The National Malaria Programme in Ivory Coast has encountered difficulty in winning public acceptance of insecticide-treated bednets. We speculate that resistance to the use of bednets could be rooted in social perceptions, beliefs and practices in the communities. The purpose of this study was to identify sociocultural and environmental factors that could be used to support promotion strategies and acceptance of impregnated bednets in Ivory Coast. Survey findings confirmed that bednets were not in widespread use among the population (25%). The most widely used methods were burning mosquito coils (50%) and indoor spraying (31%). Use of impregnated bednets was low (6%). Most survey respondents (73%) indicated initial appreciation for the effectiveness of bednets in protecting against mosquitoes as a nuisance. However only 9% of respondents thought that impregnated bednets provided protection against malaria although they did not necessarily use them. Design was a determinant factor for the use, and even acceptance, of bednets. The population want rectangular, permanently impregnated bednets large enough to accommodate at least 2 persons. Cost was a major obstacle to wider use by the population. According to our data the best price for the population would be between 2000 and 2500 FCFA as compared to the current price of 3500 FCFA in Ivory Coast.

Representations sociales et pratiques liees a l'utilisation des moustiquaires dans la lutte contre le paludisme en Cote d'Ivoire (Afrique de l'Ouest)

Devant les difficultes que rencontre le Programme National de Lutte contre le Paludisme (PNLP) de Cote d'Ivoire; dans sa volonte d'amener les populations a adopter les moustiquaires impregnees d'insecticide; nous nous sommes demandes si les representations sociales; les attitudes et les pratiques des communautes liees a l'utilisation des moustiquaires n'expliquent pas cette contre-performance. Notre etude a eu pour but de documenter les facteurs socioculturels et environnementaux pour renforcer les strategies de promotion et de vulgarisation de la moustiquaire impregnee en Cote d'Ivoire. Les resultats obtenus montrent qu'au niveau des enquetes quantitatives; la moustiquaire en general est faiblement utilisee par les populations (25). Les moyens les plus utilises sont les serpentins fumigenes (50) et les bombes aerosols (31). La moustiquaire impregnee est tres faiblement utilisee (6). La moustiquaire est; de maniere generale; appreciee dans un premier temps pour son efficacite dans la protection contre les nuisances dues aux moustiques par 73des enquetes. Seulement 9de ces enquetes pensent que la moustiquaire impregnee sert a se proteger contre le paludisme; mais ne l'utilisent pas necessairement. L'organisation des unites de couchage; voire leur inadaptation; sont determinantes dans l'utilisation de la moustiquaire. La moustiquaire souhaitee par les populations est celle d'au moins 2 places; de forme rectangulaire; de couleur blanche; faite en tulle a mailles fines; transparente; impregnee d'insecticide et a impregnation definitive. Toutefois; son cout semble etre le handicap majeur a son adoption par les populations; pour qui le cout ideal de la moustiquaire a l'achat; se situe entre 2000 et 2500 FCFA contre les 3 500 Frs actuellement pratiques en Cote d'Ivoire

[Impact of resistance of Anopheles gambiae s.s. to permethrin and deltamethrin on the efficacy of impregnated mosquito nets]. / Impact de la résistance d'Anopheles gambiae s.s. à la perméthrine et à la deltaméthrine sur l'efficacité des moustiquaires imprégnées.

Trials to assess the impact of resistance of Anopheles gambiae s.s. to permethrin and deltamethrin on the efficacy of insecticide-treated bednets were carried out from October 1997 to April 1998 in six experimental huts at the Yaokoffikro testing station in Côte d'Ivoire. Six polyester bednets were used. Two bednets were treated with permethrin at a dose of 500 mg/m2 and two with deltamethrin at 25 mg/m2. The remaining two untreated bednets served as controls. The number of Anopheles gambiae s.s. entering the hut was reduced 18% with permethrin-treated bednets and 43% with deltamethrin-treated bednets. Threefold fewer female mosquitoes were found under insecticide-treated bednets than under untreated nets (controls). The number of mosquitoes passing through the treated net was threefold lower. The number of mosquitoes exiting from the treated bednets increased twofold. The blood-feeding rate dropped by 55%. Forty percent of mosquitoes entering the permethrin-treated bednets and 56% entering the deltamethrin-treated bednets died. Immediate mortality was always greater (> 85%) than delayed mortality (< 15%). Bioassays confirmed the results from hut experiments. A lower knockdown effect was recorded with permethrin in the resistant strain. Conversely deltamethrin showed the same knockdown effects in the susceptible (Kisumu) and resistant (Yaokoffikro) strain. Mortality rates were low with both permethrin and deltamethrin. This study shows that, even in areas where Anopheles gambiae s.s. is resistant to permethrin and deltamethrin, bednets treated with these insecticides remain effective and can still be considered as an excellent method of personal protection.