detection and impact of bvdv in wild ruminants n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Detection and Impact of BVDV in Wild Ruminants PowerPoint Presentation
Download Presentation
Detection and Impact of BVDV in Wild Ruminants

Loading in 2 Seconds...

play fullscreen
1 / 24

Detection and Impact of BVDV in Wild Ruminants - PowerPoint PPT Presentation


  • 125 Views
  • Uploaded on

Detection and Impact of BVDV in Wild Ruminants. Julia Ridpath NADC/ARS/USDA. Picture courtesy of Michigan Department of Natural Resources. Impact of BVDV in wild ruminants?. Do wild ruminant populations act as BVDV reservoirs? Is there transfer between domestic and free living ruminants?

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Detection and Impact of BVDV in Wild Ruminants' - dillon-drake


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
impact of bvdv in wild ruminants
Impact of BVDV in wild ruminants?
  • Do wild ruminant populations act as BVDV reservoirs?
    • Is there transfer between domestic and free living ruminants?
  • Do BVDV infections have a negative impact on wildlife populations?
does bvdv circulate in wild ruminant populations
Does BVDV circulate in wild ruminant populations?
  • Two lines of evidence
    • Serology
      • Antelope (eland), African buffalo, Bison (European & American), Big horn sheep, camelids (llama, alpaca) Cervidae (roe deer, red deer, fallow deer, mule deer, white tailed deer, caribou), chamois, giraffe, pronghorn
    • Isolation of virus
      • Antelope (eland), Bison (European & American), Cervidae (roe deer, red deer, fallow deer, mule deer, white tailed deer)
slide6

Can wildlife act as reservoir for BVDV?

  • BVDV PI animals in wildlife populations?
    • prevalence?
  • Transmission between domestic and free living species?
    • Can it happen?
    • How efficient is transmission?
persistently infected wildlife
Persistently infected wildlife

Do they exist in the field?

slide8

Persistently infected wildlife

Can they be generated experimentally?

  • Passler et al., 2007 - inoculation
  • Duncan et al., 2008 - inoculation
  • Ridpath et al., 2008 - inoculation
  • Passler et al., 2008 - exposure to PI cattle
slide9

Are PI deer a source of infection for cattle?

  • How many PI deer are out there?
    • Survival rates
    • Limited size of herd may limit spread between deer
      • Confounded by feeding by humans
transmission
Transmission?
  • Can it occur?
  • How frequently does it occur?
    • Predominantly cattle to wildlife?
    • How efficient is transmission?
    • Does the virus change with transmission?
experimental transmission
Experimental Transmission
  • PI cattle to deer - Passler et al., 2008
  • PI deer to deer - Passler et al
  • Acutely infected deer to cattle - Ridpath et al.
transmission following acute infection of deer
Transmission following acute infection of deer
  • 3 fawns tested free of BVDV and antibodies against BVDV and 3 calves tested free of BVDV and antibodies against BVDV
  • Fawns inoculated by oral nasal route with 106 TCID BVDV2
  • Fawns and calves housed in BL2 containment
    • No direct contactbetween two species
    • Calves fed with feeding equipment used by fawns, housed in deer contaminated rooms
isolation of virus
Isolation of virus
  • Virus first isolated from all three fawns on day 6 post inoculation of fawns
  • Virus isolated from 2 calves on day 11 post inoculation of fawns
    • All three calves seroconverted
  • Sequence of virus isolated from fawns matched sequence of virus isolated from calves
slide15

Impact of BVDV infection in wildlife

  • Clinical presentation
  • Does infection have a signigicant negative impact?
experimental infection
Experimental infection
  • Acute disease
    • Subclinical
      • Van Campen et al., 1997
    • Clinically mild
      • Fever, reduced appetite, decrease in circulating lymphocytes (Ridpath et al, 2007)
  • Reproductive disease - Ridpath et al., 2008
    • Infects dam, crosses placenta
    • Fetal death
      • Fetal reabsorption
      • Mummification
      • Expulsion
    • Persistent infection
    • Serum antibodies in dam protect fetus
reproductive disease
Reproductive Disease

Does in 6th to 7th week of pregnancy

Inoculated with 106 TCID BVDV1b or BVDV2a isolated from free living deer

Housed in BL2 containment for entire experiment

impact in wildlife
Impact in Wildlife

Introduction or reintroduction of naïve species into ecosystem with circulating BVDV

slide20

BDV in reintroduced chamois

  • Game animal hunted to near extinction in Europe
  • Successfully reintroduced to Pyrenes
  • Population die off reported
  • Marco et al, 2003
  • Schelcher & Alzieu, 2003
  • Clinical presentation
    • Depression
    • Weakness and difficulty in movement
    • Alopecia and hyperpigmentation
  • Caused by BDV
slide22

Does a BVDV strain change when it is transmitted to a new host

  • Do changes occur?
  • Do changes affect detection or control?
adaptation of virus
Adaptation of virus

Binding

No Binding

slide24

Knowledge gaps

  • Prevalence of PI
  • Does virulence vary with species?
  • Does the virus change in response to new host?
  • What is the best approach to management of BVDV in free living ruminants?