Inhibition of adult emergence of Aedes aegypti in simulated domestic water-storage containers by using a controlled-release formulation of pyriproxyfen.
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.
Seng
Chang Moh
CM
World Health Organization, PO Box 1217, Phnom Penh, Cambodia.
Setha
To
T
Chanta
Ngan
N
Socheat
Duong
D
Guillet
Pierre
P
Nathan
Michael B
MB
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
D003692:Delayed-Action Preparations; D011725:Pyridines; C055613:pyriproxyfen