Dr. Darin Madson - Porcine Epidemic Diarrhea Virus Update

3,287
-1

Published on

Porcine Epidemic Diarrhea Virus Update - Dr. Darin Madson, Iowa State University, Veterinary Diagnostic Lab, from the 2013 Boehringer Ingelheim Swine Health Seminar, August 16-18, 2013, Wrightsville Beach, NC, USA.

More presentations at http://www.swinecast.com/2013-boehringer-ingelheim-carolina-swine-health-seminar

Published in: Health & Medicine, Technology
0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
3,287
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
154
Comments
0
Likes
4
Embeds 0
No embeds

No notes for slide

Dr. Darin Madson - Porcine Epidemic Diarrhea Virus Update

  1. 1. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus Update Darin Madson ISU-VDL madson@iastate.edu
  2. 2. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Coronavirus – TGE-like outbreaks  England  1971 • Multiple European Countries » Most often in nursery/grow finish pigs • More recently an issue in Asia » China » Japan » Korea – Severe epizootic outbreaks Other swine coronaviruses 1. TGE 2. PRCV 3. HEV
  3. 3. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Difficult to propagate in cell culture • Vero cells with trypsin – African green monkey kidney cells • Only one serotype known – European isolates similar to Asian isolates • US isolate(s) • 99.8% similar to 2012 china isolate in genbank
  4. 4. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Enveloped, single-stranded RNA virus • 7 open reading frames  encode 4 structural proteins – Spike protein (S gene) – Membrane (M) – Envelope (E) – Nucleoprotein (N gene) • Highly conserved; best for testing Dr. E. Burrough
  5. 5. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  6. 6. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Transmission – Only infectious to swine – Not humans or other species – Fecal-oral transmission • Outbreaks with 4-5 days after pig movements • Pig-to-pig transmission – Shedding for 7-9 days – No long term virus carriers have been reported to date • Biosecurity – Trucks, boots, fomites, etc. – Similar to TGE
  7. 7. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Outcomes of infection – Endemic • Lactogenic immunity is protective to piglets – Eliminated
  8. 8. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Pathogenesis – Viral attack of mature villous enterocytes • Diffusely through the small intestine • Cytoplasmic replication • Incubation time = 12-18 hrs • Severe diarrhea at  24-36 hrs (maximum effect) – Post infection • Rare detection in colonocytes – No destruction though
  9. 9. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus Villous to crypt ratio 7:1
  10. 10. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  11. 11. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  12. 12. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus Villous to crypt ratio 3:1
  13. 13. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  14. 14. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  15. 15. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • PEDV has not been detected outside the intestinal tract • Previous reports, anyway • Lung and mesenteric lymph node? • PEDV is supposedly less severe than TGE • ISU cases support similar severity to TGE
  16. 16. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Clinical disease – Watery diarrhea • Smells like TGE (literally if you can smell TGE) • Suckling pigs most severely affected • ~100% morbidity in acute cases • ~50% mortality from dehydration – Vomiting (possible)
  17. 17. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  18. 18. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • Properties – Stable between a pH of 5-9 – Heat inactivated at 60°C of 30 mins – Moderately stable at 50°C
  19. 19. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus Pospischil et al 2002
  20. 20. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • The story……………….. Case Date Location Farm type 1 04/29/13 Iowa Sow 2 05/01/13 Iowa Sow 3 05/06/13 Iowa Nursery 4 05/06/13 Iowa Nursery 5 05/07/13 Indiana Sow 6 05/08/13 Indiana Sow
  21. 21. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • All cases had severe diarrhea – Some vomiting • All TGE negative – Samples sent to SDSU and Minnesota as well • Severe atrophic enteritis • Sent feces to NVSL for Election microscopy (EM) – Positive for coronavirus-like particle (5-10-13)
  22. 22. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus • NVSL PCR testing for PEDV – Positive on 5-11-2013 • Announcement – 5-17-2013 • My life changed 5-17-2003 
  23. 23. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  24. 24. Veterinary Diagnostic Laboratory Iowa State University Porcine Epidemic Diarrhea Virus
  25. 25. Veterinary Diagnostic Laboratory Iowa State University Available PEDv Diagnostics • PCR • Multiple PCR tested • S gene, N gene, and nested • Currently running – N gene real-time – S gene gel based is the back up – Nested is the third confirmatory test • PCR samples – Feces, intestine, oral fluids, feed, Swiffer Retrospective testing – 800+ samples
  26. 26. Veterinary Diagnostic Laboratory Iowa State University Available PEDv Diagnostics • Immunohistochemistry – Fixed samples • Not as sensitive as PCR • Serology – IFA (very soon) • Dr. Yoon’s Lab has been able to culture the virus – ELISA  not yet IHC development 5-25-2013 No retrospective testing to date
  27. 27. Veterinary Diagnostic Laboratory Iowa State University PEDv Research and Hearsay • Feed; potential infection source?????? – Numerous samples tested • Whole feed, premixes, plasma sources, etc. • 2 samples  positive on multiple PCRs – Vitamin premix – Plasma product • Infectivity unknown – Swine bioassays needed
  28. 28. Veterinary Diagnostic Laboratory Iowa State University PEDv Research • Pathogenesis studies  underway – Weaned pig study – Neonatal pig study • Evaluating • Shedding • Oral fluid detected • Microscopic lesions • Clinical signs
  29. 29. Veterinary Diagnostic Laboratory Iowa State University PEDv Research Weaned Pig Study • Diarrhea 2-3 days post inoculation • Little vomiting @ 3-4 days • Extensive diarrhea @ 4-6 days post inoculation • Recovery @ 8 days; no depression with scant diarrhea • No weight gain for 7 days • PCR testing  N/A yet Neonatal pig study • Diarrhea at 24 hours post inoculation • Severe diarrhea at 36 hours; all pigs • Severe emaciation and dehydration @ 48 hours • Mortality 36-72 hours Preliminary data
  30. 30. Veterinary Diagnostic Laboratory Iowa State University PEDv Research Weaned pigs DPI 3
  31. 31. Veterinary Diagnostic Laboratory Iowa State University PORCINE EPIDEMIC DIARRHEA VIRUS What is next????? Questions??? Acknowledgments Dr. Drew Magstadt Dr. Paulo Arruda Dr. Yoon Dr. Stevenson

×