Experimental hut evaluation of the pyrrole insecticide chlorfenapyr on bed nets for the control of Anopheles arabiensis and Culex quinquefasciatus
Tropical Medicine and International Health
Kilimanjaro Christian Medical Centre, Moshi, Tanzania; London School of Hygiene and Tropical Medicine, London, United Kingdom; Amani Medical Research Centre, National Institute of Medical Research, Muheza, Tanzania; London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
Objective: To determine the efficacy of chlorfenapyr against Anopheles arabiensis and Culex quinquefasciatus in East Africa and to identify effective dosages for net treatment in comparison with the commonly used pyrethroid deltamethrin. Methods: Chlorfenapyr was evaluated on bed nets in experimental huts against A. arabiensis and C. quinquefasciatus in Northern Tanzania, at application rates of 100-500 mg/m2. Results: In experimental huts, mortality rates in A. arabiensis were high (46.0-63.9%) for all dosages of chlorfenapyr and were similar to that of deltamethrin-treated nets. Mortality rates in C. quinquefasciatus were higher for chlorfenapyr than for deltamethrin. Despite a reputation for being slow acting, >90% of insecticide-induced mortality in laboratory tunnel tests and experimental huts occurred within 24 h, and the speed of killing was no slower than for deltamethrin-treated nets. Conclusions: Chlorfenapyr induced low irritability and knockdown, which explains the relatively small reduction in blood-feeding rate. Combining chlorfenapyr with a more excito-repellent pyrethroid on bed nets for improved personal protection, control of pyrethroid-resistant mosquitoes and pyrethroid resistance management would be advantageous. © 2008 Blackwell Publishing Ltd.
chlorfenapyr; deltamethrin; insecticide; unclassified drug; blood; comparative study; disease control; experimental study; impregnated bednet; laboratory method; mortality; mosquito; pesticide resistance; pyrethroid; resistance management; Anopheles; article; bed net; bioassay; controlled study; Culex quinquefasciatus; drug efficacy; female; laboratory test; mortality; nonhuman; pest control; Animals; Anopheles; Bedding and Linens; Culex; Female; Housing; Insecticides; Mosquito Control; Nitriles; Pyrethrins; Tanzania; Africa; East Africa; Sub-Saharan Africa; Anopheles arabiensis; Culex pipiens quinquefasciatus