title: Inhibition of adult emergence of Aedes aegypti in simulated domestic water-storage containers by using a controlled-release formulation of pyriproxyfen.
abstract: Concrete domestic water-storage jars are a common larval habitat of the dengue vector Aedes aegypti in countries of Southeast Asia. The efficacy of a novel controlled-release formulation of the insect growth regulator pyriproxyfen, designed to inhibit adult emergence for 6 months (the approximate duration of the main dengue transmission season in many endemic countries) was tested in Cambodia against a local strain of Ae. aegypti in 200-liter jars. The resin-based formulation contained 4.8% active ingredient (AI). At target dosages of 18, 27, and 36 ppb of AI, inhibition of adult emergence remained above 95% for at least 2 months. After 3 months at 18 ppb AI, the residual efficacy was significantly lower than for the higher dosages (P < 0.05). At the higher dosages, inhibition of adult emergence was > or = 87% for 6 months. At a dosage of 27 ppb AI, monthly removal and replacement of two thirds of the water did not reduce efficacy (P > 0.05). Potential operational advantages and challenges of using the formulation are discussed. Larger-scale efficacy studies are recommended in community settings.
authors.affiliation: World Health Organization, PO Box 1217, Phnom Penh, Cambodia.
authors.forename: Chang Moh
authors.initials: CM
authors.lastname: Seng
authors.forename: To
authors.initials: T
authors.lastname: Setha
authors.forename: Ngan
authors.initials: N
authors.lastname: Chanta
authors.forename: Duong
authors.initials: D
authors.lastname: Socheat
authors.forename: Pierre
authors.initials: P
authors.lastname: Guillet
authors.forename: Michael B
authors.initials: MB
authors.lastname: Nathan
mesh_terms: D000330:Aedes; D000818:Animals; D002160:Cambodia; D003692:Delayed-Action Preparations; D007814:Larva; D009032:Mosquito Control / Q000379:methods*; D011725:Pyridines / Q000008:administration & dosage; D014881:Water Supply
chemical_list: D003692:Delayed-Action Preparations; D011725:Pyridines; C055613:pyriproxyfen