title: West Nile virus in California.
abstract: West Nile virus (WNV) was first isolated in California during July 2003 from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV transmission then increased and spread in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside to San Diego County. WNV was reported concurrently from Arizona in mid-August and from Baja, Mexico, in mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed.
authors.affiliation: University of California, Davis, California, USA. arbo123@pacbell.net
authors.forename: William
authors.initials: W
authors.lastname: Reisen
authors.forename: Hugh
authors.initials: H
authors.lastname: Lothrop
authors.forename: Robert
authors.initials: R
authors.lastname: Chiles
authors.forename: Minoo
authors.initials: M
authors.lastname: Madon
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cossen
authors.forename: Leslie
authors.initials: L
authors.lastname: Woods
authors.forename: Stan
authors.initials: S
authors.lastname: Husted
authors.forename: Vicki
authors.initials: V
authors.lastname: Kramer
authors.forename: John
authors.initials: J
authors.lastname: Edman
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology / Q000635:transmission / Q000821:virology; D001717:Birds / Q000821:virology; D002140:California / Q000453:epidemiology; D002645:Chickens / Q000821:virology; D002980:Climate; D003465:Culex / Q000821:virology; D018571:Sentinel Surveillance; D014901:West Nile Fever / Q000453:epidemiology* / Q000635:transmission* / Q000662:veterinary / Q000821:virology; D014902:West Nile virus