1921
Volume 78, Issue 1
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645

Abstract

Although horse cases frequently are reported during West Nile virus (WNV) outbreaks, few investigations have focused on the epidemiology of this transmission. From April to October 2003 to 2005, mosquito abundance and infection were monitored 3 days per week at an equine research facility at the University of California, Davis. Thirty-two nonvaccinated horses enrolled as controls in a vaccine study were bled monthly, and their serum was tested for evidence of WNV infection by plaque reduction neutralization test (PRNT). In 2004, one positive pool was associated with a single horse that presented with confirmed WNV disease in late September. The annual incidence of clinical and subclinical WNV infection in the nonvaccinated horses was 16%, with an apparent to inapparent ratio of 1:4 among infected horses. In 2005, two and two WNV-positive pools were associated with an equine infection incidence of 62%, with an apparent to inapparent ratio of 1:17. The majority (79%) of 70 blood-engorged fed on birds and the remaining on equines (21%). Conversely, fed primarily on equines (n = 23, 74%), followed by birds (n = 7, 23%) and 1 (3%) fed on a lagomorph. These data indicated that nonvaccinated horses were a sensitive indicator of WNV activity and that their risk of infection was associated with the presence of infection in and , which served as both enzootic and bridge vectors amplifying WNV among birds and transmitting WNV to horses.

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References

  1. USDA. 2007. Animal Health Monitoring & Surveillance. Available at: http://www.aphis.usda.gov/vs/nahss/equine/wnv/wnv-distribution_maps.htm.
  2. Kleiboeker SB, Loiacono CM, Rottinghaus A, Pue HL, Johnson GC, 2004. Diagnosis of West Nile virus infection in horses. J Vet Diagn Invest 16 : 2–10.
  3. Ostlund EN, Crom RL, Pedersen DD, Johnson DJ, Williams WO, Schmitt BJ, 2001. Equine West Nile encephalitis, United States. Emerg Infect Dis 7 : 665–669.
  4. Hullinger P, Sun B, Wetherall K, Stull J, Boone T, 2005. 2004 West Nile Virus Outbreak in California: Characterization of Equine Cases. CDC 6th National Conference on West Nile virus in the United States, San Jose, CA. February 8–9, 2005.
  5. Komar N, 2003. West Nile virus: epidemiology and ecology in North America. Adv Virus Res 61 : 185–234.
  6. Gubler DJ, Campbell GL, Nasci R, Komar N, Petersen L, Roehrig JT, 2000. West Nile virus in the United States: guidelines for detection, prevention, and control. Viral Immunol 13 : 469–475.
  7. Ng T, Hathaway D, Jennings N, Champ D, Chiang YW, Chu HJ, 2003. Equine vaccine for West Nile virus. Dev Biol (Basel) 114 : 221–227.
  8. CDFA, 2004. Surveillance Case Definitions for West Nile Virus Disease in Equines. Sacramento, CA: California Department of Food and Agriculture (CDFA).
  9. Reisen WK, Fang Y, Martinez VM, 2006. Effects of temperature on the transmission of West Nile virus by Culex tarsalis (Diptera: Culicidae). J Med Entomol 43 : 309–317.
  10. 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 : 1369–1378.
  11. Hom A, Marcus L, Kramer VL, Cahoon B, Glaser C, Cossen C, Baylis E, Jean C, Tu E, Eldridge BF, Carney R, Padgett K, Sun B, Reisen WK, Woods L, Husted S, 2005. Surveillance for mosquito-borne encephalitis virus activity and human disease, including West Nile virus, in California, 2004. Proc Mosq Vector Control Assoc Calif 73 : 66–77.
  12. Elnaimen DEA, Kelley K, Wright SA, Laffey R, Yoshimura G, Armijos V, Reed M, Goodman G, Reisen WK, Brown DA, 2006. Epidemic amplification of West Nile virus in Sacramento and Yolo Counties, June–September 2005. Proc Mosq Vector Control Assoc Calif 74 : 18–20.
  13. Anonymous, 2005. Horse Industry Statistics. Washington, DC: American Horse Council Foundation. Available at: http://www.horsecouncil.org/statistics.htm. Accessed January 17, 2007.
  14. CDFA, 2005. Equine West Nile Surveillance Results. Sacramento, CA: California Department of Food and Agriculture.
  15. Reeves WC, Asman SM, Hardy JL, Milby MM, Reisen WK, 1990. Epidemiology and Control of Mosquito-Borne Arboviruses in California, 1943–1987. Sacramento, CA: California Mosquito Vector Control Association.
  16. Reisen WK, Chambers TJ, Monath TP, 2003. Epidemiology of St. Louis encephalitis virus. Marmamorosch K, Murphy FA, eds. The Flaviviruses: Detection, Diagnosis and Vaccine Development. San Diego, CA: Elsevier Academic Press, 139–183.
  17. Turell MJ, O’Guinn M, Oliver J, 2000. Potential for New York mosquitoes to transmit West Nile virus. Am J Trop Med Hyg 62 : 413–414.
  18. Goddard LB, Roth AE, Reisen WK, Scott TW, 2002. Vector competence of California mosquitoes for West Nile virus. Emerg Infect Dis 8 : 1385–1391.
  19. Turell MJ, O’Guinn ML, Dohm DJ, Jones JW, 2001. Vector competence of North American mosquitoes (Diptera: Culicidae) for West Nile virus. J Med Entomol 38 : 130–134.
  20. Spielman A, 2001. Structure and seasonality of nearctic Culex pipiens populations. Ann NY Acad Sci 951 : 220–234.
  21. Apperson CS, Hassan HK, Harrison BA, Savage HM, Aspen SE, Farajollahi A, Crans W, Daniels TJ, Falco RC, Benedict M, Anderson M, McMillen L, Unnasch TR, 2004. Host feeding patterns of established and potential mosquito vectors of West Nile virus in the eastern United States. Vector Borne Zoonotic Dis 4 : 71–82.
  22. 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 : 116–127.
  23. Tempelis CH, Washino RK, 1967. Host-feeding patterns of Culex tarsalis in the Sacramento Valley, California, with notes on other species. J Med Entomol 4 : 315–318.
  24. Tempelis CH, Reeves WC, Bellamy RE, Lofy MF, 1965. A three-year study of the feeding habits of Culex tarsalis in Kern County, California. Am J Trop Med Hyg 14 : 170–177.
  25. Brownstein JS, Holford TR, Fish D, 2004. Enhancing West Nile virus surveillance, United States. Emerg Infect Dis 10 : 1129–1133.
  26. Gardner IA, Wong SJ, Ferraro GL, Balasuriya UB, Hullinger PJ, Wilson WD, Shi PY, MacLachlan NJ, 2007. Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. Vet Res 38 : 109–116.
  27. Ostlund EN, Andresen JE, Andresen M, 2000. West Nile encephalitis. Vet Clin North Am Equine Pract 16 : 427–441.
  28. 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 : 30–35.
  29. Rohe DL, Fall RP, 1979. A miniature battery powered CO2 baited trap for mosquito borne encephalitis surveillance. Bull Soc Vector Ecol 4 : 24–27.
  30. 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 : 170–176.
  31. 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 : 15–17.
  32. Meyer RP, 1985. 1987. The “walk-in” type red box for sampling resting adult mosquitoes. Proc N J Mosq Contr Assoc 72 : 104.
  33. Chow E, Wirtz RA, Scott TW, 1993. Identification of blood meals in Aedes aegypti by antibody sandwich enzyme-linked immunosorbent assay. J Am Mosq Control Assoc 9 : 196–205.
  34. Ebel GD, Dupuis AP 2nd, Nicholas D, Young D, Maffei J, Kramer LD, 2002. Detection by enzyme-linked immunosorbent assay of antibodies to West Nile virus in birds. Emerg Infect Dis 8 : 979–982.
  35. Chiles RE, Reisen WK, 1998. A new enzyme immunoassay to detect antibodies to arboviruses in the blood of wild birds. J Vector Ecol 23 : 123–135.
  36. Biggerstaff BJ, 2003. PooledInfRate, u.3.0, http://www.cdc.gov/Ncidod/dvbid/westnile/software.htm. Ft. Collins, CO: Centers for Disease Control and Prevention, 1–5.
  37. Rothman KJ, Greenland S, 1988. Modern Epidemiology. Philadelphia: Lippincott-Raven.
  38. California Department of Public Health, 2006. California West Nile Virus. http://westnile.ca.gov, accessed March 20, 2007.
  39. Hom A, Houchin A, McCaughey K, Kramer VL, Chiles RE, Reisen WK, Tu E, Glaser C, Cossen C, Baylis E, Eldridge BF, Sun B, Padgett K, Woods L, Marcus L, Hui LT, Castro M, Husted S, 2004. Surveillance for mosquito-borne encephalitis activity and human disease, including West Nile virus in California, 2003. Proc Mosq Vector Control Assoc Calif 72 : 48–54.
  40. Armijos V, Wright SA, Reisen WK, Kelly K, Yamamoto S, Brown DA, 2005. West Nile Virus in Sacramento and Yolo counties, 2004. Proc Calif Mosq Control Assoc 73 : 24–27.
  41. Ward MP, 2005. Epidemic West Nile virus encephalomyelitis: a temperature-dependent, spatial model of disease dynamics. Prev Vet Med 71 : 253–264.
  42. Trock SC, Meade BJ, Glaser AL, Ostlund EN, Lanciotti RS, Cropp BC, Kulasekera V, Kramer LD, Komar N, 2001. West Nile virus outbreak among horses in New York State, 1999 and 2000. Emerg Infect Dis 7 : 745–747.
  43. Murgue B, Murri S, Zientara S, Durand B, Durand JP, Zeller H, 2001. West Nile outbreak in horses in southern France, 2000: the return after 35 years. Emerg Infect Dis 7 : 692–696.
  44. Reisen WK, 1995. Effect of temperature on Culex tarsalis (Diptera: Culicidae) from the Coachella and San Joaquin Valleys of California. J Med Entomol 32 : 636–645.
  45. Apperson CS, Harrison BA, Unnasch TR, Hassan HK, Irby WS, Savage HM, Aspen SE, Watson DW, Rueda LM, Engber BR, Nasci RS, 2002. Host-feeding habits of Culex and other mosquitoes (Diptera: Culicidae) in the borough of Queens in New York City, with characters and techniques for identification of Culex mosquitoes. J Med Entomol 39 : 777–785.
  46. Kilpatrick AM, Kramer LD, Jones MJ, Marra PP, Daszak P, 2006. West Nile virus epidemics in North America are driven by shifts in mosquito feeding behavior. PLoS Biol 4 : e82.
  47. Gingrich JB, Williams GM, 2005. Host-feeding patterns of suspected West Nile virus mosquito vectors in Delaware, 2001–2002. J Am Mosq Control Assoc 21 : 194–200.
  48. Petersen LR, Roehrig JT, Hughes JM, 2002. West Nile virus encephalitis. N Engl J Med 347 : 1225–1226.
  49. Tempelis CH, Francy DB, Hayes RO, Lofy MF, 1967. Variations in feeding patterns of seven culicine mosquitoes on vertebrate hosts in Weld and Larimar counties, Colorado. Am J Trop Med Hyg 16 : 111–119.
  50. Fonseca DM, Keyghobadi N, Malcolm CA, Mehmet C, Schaffner F, Mogi M, Fleischer RC, Wilkerson RC, 2004. Emerging vectors in the Culex pipiens complex. Science 303 : 1535–1538.
  51. Reisen WK, Presser SB, Lin J, Enge B, Hardy JL, Emmons RW, 1994. Viremia and serological responses in adult chickens infected with western equine encephalomyelitis and St. Louis encephalitis viruses. J Am Mosq Control Assoc 10 : 549–555.
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  • Received : 30 Apr 2007
  • Accepted : 23 Oct 2007

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