West Nile virus on the Prairies

of 31

Please download to get full document.

View again

All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
PDF
31 pages
0 downs
16 views
Share
Description
West Nile virus on the Prairies. Tasha Epp, DVM, PhD October 5, 2010. WNV 1999, New York. Spread across USA - 1999. Spread across USA - 2000. Spread across USA - 2001. Spread across USA – 2002. Spread across USA - 2003. Great Plains and WNv. Birds and WNv. Virus. Family: Flaviviridae
Transcript
1West Nile virus on the Prairies Tasha Epp, DVM, PhD October 5, 2010 2WNV 1999, New York 4Spread across USA - 1999 5Spread across USA - 2000 6Spread across USA - 2001 7Spread across USA – 2002 8Spread across USA - 2003 9Great Plains and WNv 10Birds and WNv 11Virus
  • Family: Flaviviridae
  • Genus: Flavivirus Japanese Encephalitis Antigenic complex
  • Includes JE, WNV, Kunjin, Murray Valley encephalitis, SLE, etc
  • RNA, single stranded
  • 12Natural Cycle 13Species affected
  • Birds
  • Mosquitoes
  • Humans, horses
  • alpacas, camels, sheep, squirrels, reptiles, etc
  • 14Clinical Disease
  • Humans
  • Asymptomatic
  • WNV Fever
  • WNV neuro-invasive
  • Other mammals or birds
  • Neurological symptoms (mild to severe)
  • Death
  • 15Long Term Outcomes - Humans
  • Symptoms reported “post-recovery”
  • Self-reported fatigue
  • Memory problems
  • Extremity weakness
  • Word-finding difficulty
  • Headaches
  • Depression
  • Attention deficits
  • 16Surveillance in Prairies from 2002-2010
  • 2002
  • Humans, horses and birds in Manitoba
  • first bird and clinical horses reported in SK
  • 2003
  • epidemic (birds, horses, humans, etc) in SK and MB
  • First cases in AB
  • 2004 – 2006
  • Mild years, very few cases
  • 2007
  • epidemic returns in full force on prairies
  • 2008-2010
  • Few cases reported
  • 172003: Horse, bird, human and mosq. 18Five Hills Health Region
  • Highest reported number of cases in SK
  • Seroprevalence
  • Overall 9.8% (7.4, 12.6)
  • Rural only 16.8%
  • Urban only 3.2%
  • Rural versus urban:
  • 6 times more likely to be positive (95% CI: 3, 13)
  • 19Present Surveillance in SK Regardless of the risk rating for your region, remember that there is no such thing as "risk-free". If you can be bitten by a mosquito, you can contract West Nile Virus. Source: Saskatchewan Ministry of Health, Population Health Branch 20Occupational Data
  • Mosquito exposure
  • Rural residents or workers
  • Farmers
  • Outdoor jobs or recreation
  • Tissue or fluid exposure
  • Laboratory, field or clinical workers
  • People involved in dead bird collection
  • Veterinarians
  • Pathologists
  • 21Precautions for workers http://www.cdc.gov/niosh/docs/2005-155/ http://www.phac-aspc.gc.ca/ols-bsl/wnvbio-eng.php 22Control Measures:
  • Source reduction
  • Remove standing water, etc
  • Mosquito control
  • Personnel protection
  • Larviciding
  • Adulticiding
  • Vaccination
  • Behavior modification
  • 23Mosquito Control
  • Preferred method for surveillance in SK
  • Best prevention of infection in people?
  • 24Vaccination?
  • Is this feasible?
  • Who would get vaccinated?
  • Cost-benefit analysis?
  • 25Human Behavior?
  • DEET
  • Drain
  • Dress
  • Dusk to dawn
  • 26Northern Colorado study
  • Loveland and Fort Collins
  • Similar ecology, demographics
  • High plains ecoregion
  • 90% white, around 10% >65 yrs
  • Loveland had mosquito control program
  • Less WNV-infected mosquitoes than Fort Collins
  • 27Northern Colorado study
  • Loveland had higher neuro-invasive disease rate
  • Loveland = 38.6/100,000
  • Fort Collins = 15.9/100,000
  • 28Northern Colorado study
  • Loveland residents
  • reported less use of DEET
  • Most influenced by age
  • Second influenced by risk perception
  • more likely to spend time outdoors at dusk and dawn
  • both weekdays and weekends
  • Long clothes not important
  • 29First Nations and WNv
  • Identified many activities resulting in exposure
  • Identified features of homes or yards resulting in exposure
  • Control measures
  • Smoke or Mosquito coils
  • DEET based products
  • Clothing (children versus adults)
  • 30Communicating Risk
  • When?
  • How?
  • What?
  • 31Future of WNv
  • What should we expect?
  • Is WNv here to stay?
  • Can we predict WNv years before they occur?
  • 32Questions?
    Related Search
    We Need Your Support
    Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

    Thanks to everyone for your continued support.

    No, Thanks