Insecticide susceptibility status of field-collected Aedes (Stegomyia) aegypti (L.) at a dengue endemic site in Shah Alam, Selangor, Malaysia.
Biweekly ovitrap surveillance (OS) was conducted for a year (August 2007 - September 2008) at two different dengue endemic sites in Shah Alam, Selangor, Malaysia, 50 km from Kuala Lumpur. Aedes aegypti collected from these 2 locations were raised to the F3 stage and subjected to a WHO standard bioassay method to determine lethal time (LT) against pyrethroids (permethrin 0.75%, cyfluthrin 0.15%), organophosphates (malathion 5.0%, fenitrothion 1.0%), carbamates (propoxur 0.1%, bendiocarb 0.1%) and organochlorine (DDT 4.0%). Insecticide susceptibilities were analyzed for one year. Aedes aegypti were resistant to DDT with a mortality range of 0 - 13.3% throughout the year at both sites. Susceptibilities to pyrethroids and carbamates varied throughout the year. In contrast, susceptibilities to pyrethroids and carbamates varied throughout the year: resistant to propoxur, bendiocarb and permethrin with mortality of < 80% in most months; but, showed incipient resistant to cyfluthrin in most months. Mosquitoes were consistently susceptible to malathion and fenitrothion, with complete mortality during most months. They were especially susceptible to malathion with LT50 values of 21.32 - 36.37 minutes, suggesting effectiveness of malathion for control of dengue.
Institute of Biological Science, Faculty of Sciences, University of Malaya, Kuala Lumpur, Malaysia. joserong@yahoo.com
Loke Seau
LS
Rong
Andy Tan Wei
AT
Ann
Nazni Wasi
NW
Ahmad
Lee Han
LH
Lim
Mohd Sofian
MS
Azirun
D000330:Aedes / Q000187:drug effects*; D000818:Animals; D002219:Carbamates / Q000494:pharmacology; D003634:DDT / Q000494:pharmacology; D003715:Dengue / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D007305:Insecticide Resistance / Q000187:drug effects*; D007306:Insecticides / Q000494:pharmacology*; D008296:Malaysia / Q000453:epidemiology; D010755:Organophosphates / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology; D012621:Seasons
D002219:Carbamates; D007306:Insecticides; D010755:Organophosphates; D011722:Pyrethrins; D003634:DDT