Comparative field evaluation of residual-sprayed deltamethrin WG and deltamethrin WP for the control of malaria in Pahang, Malaysia.
The bioefficacy of indoor residual-sprayed deltamethrin wettable granule (WG) formulation at 25 mg a.i./m2 and 20 mg a.i./m2 for the control of malaria was compared with the current dose of 20 mg/m2 deltamethrin wettable powder (WP) in aboriginal settlements in Kuala Lipis, Pahang, Malaysia. The malaria vector has been previously identified as Anopheles maculatus. The assessment period for the 20 mg/m2 dosage was six months, but for the 25 mg/m2 dosage, the period was 9 months. Collections of mosquitoes using the bare-leg techniques were carried out indoors and outdoors from 7:00 PM to 7:00 AM. All mosquitoes were dissected for sporozoites and parity. Larval collections were carried out at various locations to assess the extent and distribution of breeding of vectors. A high incidence of human feeds was detected during May 2005 and a low incidence during January 2005 for all the study areas. Our study showed that deltamethrin WG at 25 mg/m2 suppressed An. maculatus biting activity. More An. maculatus were caught in outdoor landing catches than indoor landing catches for all the study areas. The results indicate that 25 mg/m2 WG is good for controlling malaria for up to 9 months. Where residual spraying is envisaged, the usual two spraying cycles per year with 20 mg/m2 deltamethrin may be replaced with 25 mg/m2 deltamethrin WG every 9 months.
Rohani
Ahmad
A
Medical Entomology Unit, Infectious Disease Research Center, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia. rohania@imr.gov.my
Zamree
Ismail
I
Lim
Lee Han
LH
Rahini
Hassan
H
David
Luben
L
Kamilan
Demin
D
D016902:Air Pollution, Indoor; D000818:Animals; D000852:Anopheles / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D001733:Bites and Stings / Q000469:parasitology; D003140:Communicable Disease Control; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D006798:Housing; D006801:Humans; D007303:Insect Vectors / Q000187:drug effects / Q000469:parasitology; D007306:Insecticides / Q000008:administration & dosage* / Q000633:toxicity; D007814:Larva / Q000187:drug effects; D008288:Malaria / Q000453:epidemiology / Q000517:prevention & control*; D008296:Malaysia / Q000453:epidemiology; D009570:Nitriles / Q000008:administration & dosage* / Q000633:toxicity; D015397:Program Evaluation; D011722:Pyrethrins / Q000008:administration & dosage* / Q000633:toxicity
D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin