Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California

Ian A. Gardner, Susan J. Wong, Gregory L. Ferraro, Udeni B. Balasuriya, Pamela J. Hullinger, W. David Wilson, Pei-Yong Shi, N. James MacLachlan

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

A prospective cohort study was used to estimate the incidence of West Nile virus (WNV) infection in a group of unvaccinated horses (n = 37) in California and compare the effects of natural WNV infection in these unvaccinated horses to a group of co-mingled vaccinated horses (n = 155). Horses initially were vaccinated with either inactivated whole virus (n = 87) or canarypox recombinant (n = 68) WNV vaccines during 2003 or 2004, prior to emergence of WNV in the region. Unvaccinated horses were serologically tested for antibodies to WNV by microsphere immunoassay incorporating recombinant WNV E protein (rE MIA) in December 2003, December 2004, and every two months thereafter until November 2005. Clinical neurologic disease attributable to WNV infection (West Nile disease (WND)) developed in 2 (5.4%) of 37 unvaccinated horses and in 0 of 155 vaccinated horses. One affected horse died. Twenty one (67.7%) of 31 unvaccinated horses that were seronegative to WNV in December, 2004 seroconverted to WNV before the end of the study in November, 2005. Findings from the study indicate that currently-available commercial vaccines are effective in preventing WND and their use is financially justified because clinical disease only occurred in unvaccinated horses and the mean cost of each clinical case of WND was approximately 45 times the cost of a 2-dose WNV vaccination program.

Original languageEnglish (US)
Pages (from-to)109-116
Number of pages8
JournalVeterinary Research
Volume38
Issue number1
DOIs
StatePublished - Jan 2007
Externally publishedYes

Fingerprint

West Nile virus
Virus Diseases
Horses
horses
incidence
Incidence
infection
West Nile Virus Vaccines
vaccines
Costs and Cost Analysis
nervous system diseases
Nervous System Diseases
immunoassays
cohort studies
Microspheres
Immunoassay
Vaccination
Cohort Studies
Vaccines
vaccination

Keywords

  • Horses
  • Microsphere immunoassay
  • Vaccination
  • West Nile virus

ASJC Scopus subject areas

  • veterinary(all)

Cite this

Gardner, I. A., Wong, S. J., Ferraro, G. L., Balasuriya, U. B., Hullinger, P. J., Wilson, W. D., ... MacLachlan, N. J. (2007). Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. Veterinary Research, 38(1), 109-116. https://doi.org/10.1051/vetres:2006045

Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. / Gardner, Ian A.; Wong, Susan J.; Ferraro, Gregory L.; Balasuriya, Udeni B.; Hullinger, Pamela J.; Wilson, W. David; Shi, Pei-Yong; MacLachlan, N. James.

In: Veterinary Research, Vol. 38, No. 1, 01.2007, p. 109-116.

Research output: Contribution to journalArticle

Gardner, IA, Wong, SJ, Ferraro, GL, Balasuriya, UB, Hullinger, PJ, Wilson, WD, Shi, P-Y & MacLachlan, NJ 2007, 'Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California', Veterinary Research, vol. 38, no. 1, pp. 109-116. https://doi.org/10.1051/vetres:2006045
Gardner IA, Wong SJ, Ferraro GL, Balasuriya UB, Hullinger PJ, Wilson WD et al. Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. Veterinary Research. 2007 Jan;38(1):109-116. https://doi.org/10.1051/vetres:2006045
Gardner, Ian A. ; Wong, Susan J. ; Ferraro, Gregory L. ; Balasuriya, Udeni B. ; Hullinger, Pamela J. ; Wilson, W. David ; Shi, Pei-Yong ; MacLachlan, N. James. / Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. In: Veterinary Research. 2007 ; Vol. 38, No. 1. pp. 109-116.
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