title: Efficacy of aerial spraying of mosquito adulticide in reducing incidence of West Nile Virus, California, 2005.
abstract: Epidemic transmission of West Nile virus (WNV) in Sacramento County, California, in 2005 prompted aerial application of pyrethrin, a mosquito adulticide, over a large urban area. Statistical analyses of geographic information system datasets indicated that adulticiding reduced the number of human WNV cases within 2 treated areas compared with the untreated area of the county. When we adjusted for maximum incubation period of the virus from infection to onset of symptoms, no new cases were reported in either of the treated areas after adulticiding; 18 new cases were reported in the untreated area of Sacramento County during this time. Results indicated that the odds of infection after spraying were approximately 6x higher in the untreated area than in treated areas, and that the treatments successfully disrupted the WNV transmission cycle. Our results provide direct evidence that aerial mosquito adulticiding is effective in reducing human illness and potential death from WNV infection.
authors.affiliation: California Department of Public Health, Richmond, California, USA. ryan.carney@yale.edu
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Carney
authors.forename: Stan
authors.initials: S
authors.lastname: Husted
authors.forename: Cynthia
authors.initials: C
authors.lastname: Jean
authors.forename: Carol
authors.initials: C
authors.lastname: Glaser
authors.forename: Vicki
authors.initials: V
authors.lastname: Kramer
mesh_terms: D000818:Animals; D002140:California / Q000453:epidemiology; D003465:Culex; D006801:Humans; D015994:Incidence; D007303:Insect Vectors; D007306:Insecticides / Q000008:administration & dosage; D009032:Mosquito Control / Q000379:methods*; D011722:Pyrethrins / Q000008:administration & dosage; D014901:West Nile Fever / Q000453:epidemiology* / Q000517:prevention & control* / Q000821:virology; D014902:West Nile virus
chemical_list: D007306:Insecticides; D011722:Pyrethrins