Mosquito surveillance for West Nile virus in Connecticut, 2000: isolation from Culex pipiens, Cx. restuans, Cx. salinarius, and Culiseta melanura

• Published in: Emerging infectious diseases Vol. 7; no. 4; pp. 670 - 674
• Main Authors: Andreadis, T G, Anderson, J F, Vossbrinck, C R
• Format: Journal Article
• Language: English
• Published: United States U.S. National Center for Infectious Diseases 01-07-2001; Centers for Disease Control and Prevention
• Subjects: Animals; Cercopithecus aethiops; Communicable diseases in animals; Connecticut - epidemiology; Culex - classification; Culex - virology; Culicidae - classification; Culicidae - virology; Demographic aspects; Health aspects; identification; Insect Vectors - classification; Insect Vectors - virology; Insects as carriers of disease; isolation; Mosquitoes; Mosquitoes as carriers of disease; RT-PCR; Sentinel Surveillance - veterinary; Vero cell culture; Vero Cells; West Nile fever; West Nile Fever - epidemiology; West Nile Fever - virology; West Nile virus; West Nile virus - genetics; West Nile virus - isolation & purification; Connecticut
• ISSN: 1080-6040; 1080-6059
• DOI: 10.3201/eid0704.017413

Fourteen isolations of West Nile (WN) virus were obtained from four mosquito species (Culex pipiens [5], Cx. restuans [4], Cx. salinarius [2], and Culiseta melanura [3]) in statewide surveillance conducted from June through October 2000. Most isolates were obtained from mosquitoes collected in densely populated residential locales in Fairfield and New Haven counties, where the highest rates of dead crow sightings were reported and where WN virus was detected in 1999. Minimum field infection rates per 1,000 mosquitoes ranged from 0.5 to 1.8 (county based) and from 1.3 to 76.9 (site specific). Cx. restuans appears to be important in initiating WN virus transmission among birds in early summer; Cx. pipiens appears to play a greater role in amplifying virus later in the season. Cs. melanura could be important in the circulation of WN virus among birds in sylvan environments; Cx. salinarius is a suspected vector of WN virus to humans and horses.