West Nile Virus: in SK Horses 2003 Tasha Epp, DVM MSc graduate student, Epidemiology WCVM

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West Nile Virus in SK Horses 2003Tasha Epp,
DVM MSc graduate student, Epidemiology WCVM
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WNV Clinical Cases

• Passive system of case identification
• Clinical case neurologic symptoms and
  positive IgM ELISA
• Telephone interview of owner

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Case Information

• 64 were lt 10 yrs
• 82 were light horses
• 55 were males
• 72 were dark colored
• 83 were pleasure horses
• 68 had no shelter
• 7 were vaccinated
• 96 had no travel history

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Clinical Picture in SK
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Multi-level model

• 2-level hierarchy Horse (130) within RHA (10)
• Outcome of interest
• Health status
• Significant variables
• Color
• Gender
• Week of Onset

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Interpretation of IgG results

• Impact of vaccination on ELISA results
• Kinetics of positive IgG result once infected
• Identify a
• cut-point for
• the ELISA
• test

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Vaccination study
Vaccination dates Nov 20 and Dec 10 Cut-point
0.300
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Kinetics study
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WNV Sero-Prevalence

• 20 herds
• Sampled 10 horses
• August and October
• IgG and IgM ELISA

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IgG results

• created 5 regions with 4 herds in each
• Originally results reported as Pos or Neg/Susp
• 79 were vacc

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(No Transcript)
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Thanks

• WCVM Equine Health Research Fund
• WCVM Interprovincial Graduate Student Fellowship
  Fund
• Saskatchewan Health
• Saskatoon Health Region
• Saskatchewan Agriculture
• Canadian Co-operative Wildlife Health Center
• Wyeth Animal Health