title: Ecology of potential West Nile virus vectors in Southeastern Louisiana: enzootic transmission in the relative absence of Culex quinquefasciatus.
abstract: A study of West Nile virus (WNV) ecology was conducted in St. Tammany Parish, Louisiana, from 2002 to 2004. Mosquitoes were collected weekly throughout the year using Centers for Disease Control and Prevention (CDC) light traps placed at 1.5 and 6 m above the ground and gravid traps. A total of 379,466 mosquitoes was collected. WNV was identified in 32 pools of mosquitoes comprising four species; 23 positive pools were from Culex nigripalpus collected during 2003. Significantly more positive pools were obtained from Cx. nigripalpus collected in traps placed at 6 m than 1.5 m that year, but abundance did not differ by trap height. In contrast, Cx. nigripalpus abundance was significantly greater in traps placed at 6 m in 2002 and 2004. Annual temporal variation in Cx. nigripalpus peak seasonal abundance has important implications for WNV transmission in Louisiana. One WNV-positive pool, from Cx. erraticus, was collected during the winter of 2004, showing year-round transmission. The potential roles of additional mosquito species in WNV transmission in southeastern Louisiana are discussed.
authors.affiliation: Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA. mjg9@cdc.gov
authors.forename: Marvin S
authors.initials: MS
authors.lastname: Godsey
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: King
authors.forename: Kristen
authors.initials: K
authors.lastname: Burkhalter
authors.forename: Mark
authors.initials: M
authors.lastname: Delorey
authors.forename: Leah
authors.initials: L
authors.lastname: Colton
authors.forename: Dawn
authors.initials: D
authors.lastname: Charnetzky
authors.forename: Genevieve
authors.initials: G
authors.lastname: Sutherland
authors.forename: Vanessa O
authors.initials: VO
authors.lastname: Ezenwa
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Wilson
authors.forename: Michelle
authors.initials: M
authors.lastname: Coffey
authors.forename: Lesley E
authors.initials: LE
authors.lastname: Milheim
authors.forename: Viki G
authors.initials: VG
authors.lastname: Taylor
authors.forename: Charles
authors.initials: C
authors.lastname: Palmisano
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Wesson
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Guptill
mesh_terms: D000818:Animals; D003465:Culex / Q000145:classification / Q000502:physiology*; D007303:Insect Vectors / Q000145:classification / Q000502:physiology*; D008145:Louisiana; D009032:Mosquito Control / Q000295:instrumentation / Q000379:methods; D012621:Seasons; D013045:Species Specificity; D014901:West Nile Fever / Q000635:transmission* / Q000821:virology; D014902:West Nile virus