Volume 83, Issue 2
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



West Nile virus (WNV) invaded Los Angeles in September 2003, and during the subsequent five-year period followed a pattern of amplification, subsidence, and resurgence. Enzootic transmission was tracked by abundance and infection incidence in and and by seroprevalence in peridomestic passerine birds, infection in dead birds, and seroconversions in sentinel chickens. served as the primary vector of WNV, with gravid traps serving as the best sampling method and the most consistent indicator of viral activity. Spatial scan statistics applied to mosquito infection and positive dead bird data delimited three major clusters of WNV transmission, with introduction occurring in the Los Angeles Basin, and amplification and dispersal events carrying transmission to the San Fernando and Santa Clarita valleys. Los Angeles experienced major epidemics in 2004 and 2008, providing a unique opportunity to investigate specific patterns of enzootic amplification preceding epidemics.


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  1. Reisen W, Lothrop H, Chiles R, Madon M, Cossen C, Woods L, Husted S, Kramer V, Edman J, , 2004. West Nile virus in California. Emerg Infect Dis 10: 13691378.[Crossref] [Google Scholar]
  2. Reisen WK, Lothrop HD, Chiles RE, Madon MB, Cossen C, Woods L, Husted S, Kramer VL, Edman JD, , 2004. West Nile virus in California. Emerg Infect Dis 10: 13691378.[Crossref] [Google Scholar]
  3. Wilson J, Hazelrigg JE, Reisen WK, Madon MB, , 2004. Invasion of Greater Los Angeles by West Nile virus - 2003. Proc Mosq Vector Control Assoc Calif 72: 611. [Google Scholar]
  4. Reeves WC, Asman SM, Hardy JL, Milby MM, Reisen WK, , 1990. Epidemiology and Control of Mosquito-borne Arboviruses in California, 1943–1987. Proc Mosq Vector Control Assoc Calif 71: 1727. [Google Scholar]
  5. Reisen WK, Milby MM, Presser SB, Hardy JL, , 1992. Ecology of mosquitoes and St. Louis encephalitis virus in the Los Angeles Basin of California, 1987–1990. J Med Entomol 29: 582598.[Crossref] [Google Scholar]
  6. Murray RA, Habel LA, Mackey KJ, Wallace HG, Peck BA, Mora SJ, Ginsberg MM, Emmons RW, , 1985. Epidemiological aspects of the 1984 St. Louis encephalitis epidemic in southern California. Proc Calif Mosq Vector Control Assoc 53: 59. [Google Scholar]
  7. Emmons RW, Milby MM, Walsh JD, Reeves WC, Bayer EV, White K, Woodie JD, Murray RA, , 1985. Surveillance for arthropod-borne viral activity and disease in California during 1984. Proc Calif Mosq Vector Control Assoc 53: 14. [Google Scholar]
  8. Los Angeles County, 2009. Available at: http://portal.lacounty.gov/wps/portal/lac/residents/.
  9. U.S. Census Bureau, 2009. United States Census Bureau QuickFacts. Bureau USC, ed. State and County QuickFacts. Washington, DC: U.S. Census Bureau. Available at: http://quickfacts.census.gov/qfd/states/06/06037.html. [Google Scholar]
  10. Reveal JL, , 2000. Biomes of North America. College Park, MD: Norton-Brown Herbarium, University of Maryland. [Google Scholar]
  11. State of California Department of Water Resources, 2009. California Irrigation Management Information System. Sacramento, CA: State of California Department of Water Resources. Available at: http://www.water.ca.gov/. [Google Scholar]
  12. Los Angles County Department of Public Works, 2009. Available at: http://dpw.lacounty.gov.
  13. Greater Los Angels County Vector Control District, 2009. Available at: http://glacvcd.org.
  14. Melton F, Nemani RR, Michaelis A, Barker CM, Park B, Reisen WK, , 2008. Monitoring and modeling environmental conditions related to mosquito abundance and virus transmission risk with the NASA Terrestrial Observation and Prediction System. Proc Mosq Vector Control Assoc Calif 76: 4. [Google Scholar]
  15. PostgreSQL Global Development Group, 2009. Available at: http://www.postgresql.org/.
  16. Centers for Disease Control and Prevention, 2009. West Nile Virus: Clinical Description. Atlanta, GA: Centers for Disease Control and Prevention. [Google Scholar]
  17. Newhouse VF, Chamberlain RW, Johnston JG, Jr Sudia WD, , 1966. Use of dry ice to increase mosquito catches of the CDC miniature light trap. Mosq News 26: 3035. [Google Scholar]
  18. Rohe DL, Fall RP, , 1979. A miniature battery powered CO 2 baited trap for mosquito borne encephalitis surveillance. Bull Soc Vector Ecol 4: 2427. [Google Scholar]
  19. Cummings RF, , 1992. Design and use of a modified Reiter gravid mosquito trap for mosquito-borne encephalitis surveillance in Los Angeles County, California. Proc Mosq Vector Control Assoc Calif 60: 170176. [Google Scholar]
  20. Lanciotti RS, Kerst AJ, , 2001. Nucleic acid sequence-based amplification assays for rapid detection of West Nile and St. Louis encephalitis viruses. J Clin Microbiol 39: 45064513.[Crossref] [Google Scholar]
  21. Graham RR, Hardy JL, Presser SB, , 1986. Use of the in situ enzyme immunoassay for the rapid detection of arbovirus infections in mosquitoes in California. Proc Calif Mosq Vector Control Assoc 54: 10. [Google Scholar]
  22. Chiles RE, Green EN, Fang Y, Reisen WK, Edman JD, Brault AC, , 2004. Surveillance for arboviruses in California mosquito pools: current and future protocols. Proc Mosq Vector Control Assoc Calif 72: 1517. [Google Scholar]
  23. Biggerstaff BJ, , 2003. Pooled Infection Rate. Fort Collins, CO: Centers for Disease Control and Prevention. [Google Scholar]
  24. McCaughey K, Miles SQ, Woods L, Chiles RE, Hom A, Kramer VL, Jay-Russel M, Sun B, Reisen WK, Scott TW, Hui LT, Steinlein DB, Castro M, Houchin A, Husted S, , 2003. The California West Nile virus dead bird surveillance program. Proc Mosq Vector Control Assoc Calif 71: 3843. [Google Scholar]
  25. Lanciotti RS, Kerst AJ, Nasci RS, Godsey MS, Mitchell CJ, Savage HM, Komar N, Panella NA, Allen BC, Volpe KE, Davis BS, Roehrig JT, , 2000. Rapid detection of West Nile virus from human clinical specimens, field-collected mosquitoes, and avian samples by a TaqMan reverse transcriptase-PCR assay. J Clin Microbiol 38: 40664071. [Google Scholar]
  26. Reisen WK, Chiles RE, Martinez VM, Fang Y, Green EN, , 2003. Experimental infection of California birds with western equine encephalomyelitis and St. Louis encephalitis viruses. J Med Entomol 40: 968982.[Crossref] [Google Scholar]
  27. Reisen WK, Lin J, Presser SB, Enge B, Hardy JL, , 1993. Evaluation of new methods for sampling sentinel chickens for antibodies to WEE and SLE viruses. Proc Calif Mosq Vector Control Assoc 61: 3336. [Google Scholar]
  28. Patiris PJ, Peck GW, Chiles RE, Reisen WK, Hanson CV, , 2008. Serological diagnosis of West Nile and St. Louis encephalitis virus infections in domestic chickens. Am J Trop Med Hyg 78: 7. [Google Scholar]
  29. McClure HE, , 1984. Bird Banding. Pacific Grove, CA: Boxwood Press. [Google Scholar]
  30. Chiles RE, Reisen WK, , 1998. A new enzyme immunoassay to detect antibodies to arboviruses in the blood of wild birds. J Vector Ecol 23: 123135. [Google Scholar]
  31. Kulldorff M, and Information Management Services Inc., 2009. SaTScantm v8.0: Software for the Spatial and Space-Time Scan Statistics. Rockville, MD: Information Management Services, Inc. [Google Scholar]
  32. Kulldorff M, Athas WF, Feuer EJ, Miller BA, Key CR, , 1998. Evaluating cluster alarms: a space-time scan statistic and brain cancer in Los Alamos, New Mexico. Am J Public Health 88: 13771380.[Crossref] [Google Scholar]
  33. Kulldorff M, Nagarwalla N, , 1995. Spatial disease clusters: detection and inference. Stat Med 14: 799810.[Crossref] [Google Scholar]
  34. Reisen WK, Lothrop HD, , 1999. Effects of sampling design on the estimation of adult mosquito abundance. J Am Mosq Control Assoc 15: 104114. [Google Scholar]
  35. Dawson SW, Jr Ebel GD, Young DS, Galinski DS, Pensabene JP, Franke MA, Eidson M, Kramer LD, , 2007. Crow deaths caused by West Nile virus during winter. Emerg Infect Dis 12: 19121914.[Crossref] [Google Scholar]
  36. Oke TR, , 1982. The energetic basis of the urban heat-island. Q J R Meteorol Soc 108: 124. [Google Scholar]
  37. Acute Communicable Disease Control Los Angeles County, Department of Health Services, Public Health, 2004. West Nile virus. Wkly Epidemiol Rep 42: 2. [Google Scholar]
  38. Hayes EB, Komar N, Nasci RS, Montgomery SP, O'Leary DR, Campbell GL, , 2005. Epidemiology and transmission dynamics of West Nile Virus disease. Emerg Infect Dis 11: 11671173.[Crossref] [Google Scholar]
  39. Komar N, , 2003. West Nile virus: epidemiology and ecology in North America. Adv Virus Res 61: 185234.[Crossref] [Google Scholar]
  40. Busch MP, Wright DJ, Custer B, Tobler LH, Stramer SL, Kleinman SH, Prince HE, Bianco C, Foster G, Petersen LR, Nemo G, Glynn SA, , 2006. West Nile virus infections projected from blood donor screening data, United States, 2003. Emerg Infect Dis 12: 395402.[Crossref] [Google Scholar]
  41. Mostashari F, Bunning ML, Kitsutani PT, Singer DA, Nash D, Cooper MJ, Katz N, Liljebjelke KA, Biggerstaff BJ, Fine AD, Layton MC, Mullin SM, Johnson AJ, Martin DA, Hayes EB, Campbell GL, , 2001. Epidemic West Nile encephalitis, New York, 1999: results of a household-based seroepidemiological survey. Lancet 358: 261264.[Crossref] [Google Scholar]
  42. Reisen WK, Meyer RP, Tempelis CH, Spoehel JJ, , 1990. Mosquito abundance and bionomics in residential communities in Orange and Los Angeles Counties, California. J Med Entomol 27: 356367.[Crossref] [Google Scholar]
  43. Molaei G, Andreadis TG, Armstrong PM, Bueno R, Dennett JA, Real SV, Sargent C, Bala A, Randle Y, Guzman H, da Rosa AT, Wuithiranyagool T, Tesh RB, , 2007. Host feeding pattern of Culex quinquefasciatus (Diptera: Culicidae) and its role in transmission of West Nile virus in Harris County, Texas. Am J Trop Med Hyg 77: 7381. [Google Scholar]
  44. Urbanelli S, Silvestrini F, Reisen WK, deVito E, Bullini L, , 1997. California hybrid zone between Culex pipiens pipiens and Cx. p. quinquefasciatus revisited (Diptera: Culicidae). J Med Entomol 34: 116127.[Crossref] [Google Scholar]
  45. Barr AR, , 1957. The distribution of Culex p. pipiens and Culex p. quinquefasciatus in North America. Am J Trop Med Hyg 6: 153165. [Google Scholar]
  46. Tabachnick WJ, Powell JR, , 1983. Genetic analysis of Culex pipiens populations in the central valley of California. Ann Entomol Soc Am 76: 715720.[Crossref] [Google Scholar]
  47. Reisen WK, Fang Y, Martinez VM, , 2005. Avian host and mosquito (Diptera: Culicidae) vector competence determine the efficiency of west nile and St. Louis encephalitis virus transmission. J Med Entomol 42: 367375.[Crossref] [Google Scholar]
  48. Reisen WK, Barker CM, Fang Y, Martinez VM, , 2008. Does variation in Culex (Diptera: Culicidae) vector competence enable outbreaks of West Nile virus in California? J Med Entomol 45: 11261138.[Crossref] [Google Scholar]
  49. Wheeler SS, Barker CM, Fang Y, Armijos MV, Carroll BD, Husted S, Johnson WO, Reisen WK, , 2009. Differential impacts of West Nile virus on California birds. Condor 111: 120.[Crossref] [Google Scholar]
  50. Nielsen CF, Reisen WK, , 2007. West Nile virus-infected dead corvids increase the risk of infection in Culex mosquitoes (Diptera: Culicidae) in domestic landscapes. J Med Entomol 44: 10671073.[Crossref] [Google Scholar]
  51. Reisen WK, Barker CM, Carney R, Lothrop HD, Wheeler SS, Wilson JL, Madon MB, Takahashi R, Carroll B, Garcia S, Fang Y, Shafii M, Kahl N, Ashtari S, Kramer V, Glaser C, Jean C, , 2006. Role of corvids in epidemiology of West Nile virus in southern California. J Med Entomol 43: 356367.[Crossref] [Google Scholar]

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  • Received : 04 Feb 2010
  • Accepted : 14 Apr 2010
  • Published online : 05 Aug 2010

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