N'Guessan R., Darriet Frédéric, Doannio J.M.C., Chandre Fabrice, Carnevale Pierre. (2001). Olyset Net(R) efficacy against pyrethroid-resistant Anopheles gambiae and Culex quinquefasciatus after 3 years' field use in Côte d'Ivoire. Medical and Veterinary Entomology, 15 (1), p. 97-104. ISSN 0269-283X.
Titre du document
Olyset Net(R) efficacy against pyrethroid-resistant Anopheles gambiae and Culex quinquefasciatus after 3 years' field use in Côte d'Ivoire
Année de publication
2001
Type de document
Article
Auteurs
N'Guessan R., Darriet Frédéric, Doannio J.M.C., Chandre Fabrice, Carnevale Pierre
Source
Medical and Veterinary Entomology, 2001,
15 (1), p. 97-104 ISSN 0269-283X
Pyrethroid-impreganted bednets are advocated for personal protection against malaria vectors. To avoid the need for periodic re-treatment, it would be advantageous to have nets that retain insecticidal efficacy for years and withstand repeated washing. Such a type of commercially produced bednet with permethrin 2% incorporated in polyethylene fibres (trademark Olyset Net(R) supplied by Sumika Life-Tech Co., Osaka, Japan) was evaluated against mosquitoes in veranda-trap huts at Yaokoffikro, near Bouaké, Côte d'Ivoire, by standard WHOPES phase II procedures. Four Olyset Nets were compared with a standard untreated polyester net as control. They comprised three examples previously used in a village for over 3 years (one washed, one dirty, one very dirty) and a previously unused Olyset Net newly unwrapped, from the same orignal batch. Bioassays with 3 min exposure of susceptible Anopheles gambiae Giles (Diptera : Culicidae) gave more than 99% mortality of female mosquitoes tested on the 'new' Olyset Net. The used Olyset Nets gave mortality rates averaging 83% for the washed net, 85% for the dirty net and 55% for the very dirty net (within 24-h following 3 min exposure). Thus, Olyset Nets were found to remain remarkably effective against susceptible An. gambiae for at least 3 years under field conditions. Wild pyrethroid-resistant populations of Culex quinquefasciatus Say and An. gambiae (savanna cytotype with 96% kdr) were assessed during June-August 1999 for their responses to sleepers protected by nets in the experimental huts. With regard to hut entry by foraging female mosquitoes, Olyset Nets showed some deterrency against An. gambiae (44% reduction by the new net, approximately 20% by the dirty nets, none by the washed net), but not against Cx. quinquefasciatus. Among mosquitoes entering the hut with untreated control net, 30-34% tried to leave (exophily) but were caught in the veranda trap... (D'après résumé d'auteur)
