Comprehensive Discussion of PEDv

1. Comprehensive Discussion of PEDv 2014 Pork Management Conference June 19, 2014 Dr. Harry Snelson AASV

2. Disease Discovery Looks like TGE… Acts like TGE…. Ain’t TGE

3. PEDV Timeline – May 2013

5. Outcome of retrospective testing & on-boarding PEDVPCR

6. * for the weeks prior to 6-17-13, laboratories were able to provide diagnostic case submissions and number of premises testing positive for PEDv. Starting 6-17-13, the data are limited to ONLY diagnostic case submission numbers (aka Swine Accessions)

7. Clinical Signs • Clinically indistinguishable from TGE • Alpha coronavirus • Fecal-oral pathogen • Profuse diarrhea and vomiting • High mortality rates in neonatal pigs • High morbidity, lower mortality as pigs age • Not zoonotic, not a food safety concern

8. Diagnostics • PCR – ready quickly • Serology • IFA • ELISA • No VI – virus is difficult to grow • Bioassay to prove infectivity/viability • Time consuming • Expensive • Lacks sensitivity

12. Percent Survivability to Day 7

13. PED virus • New to North America • In Europe in 1970’s • Current virus present in Asia • U.S. virus 99+ % similar to 2012 isolate from Anhui Province in China • U.S. swine herd naïve, 100% susceptible • No vaccine • Easily transmitted

14. Response • USDA designated PED a “transboundary” disease • Not reportable • Non-regulatory • Production disease like PRRS or PCV • Turned the response over to the swine industry • NPB, NPPC and AASV coordinated effort with USDA to understand the epidemiology and develop a response strategy • Transmitted via contaminated manure • Concentrated on elevating biosecurity

15. AASV Response • Collaboration with producer groups, state/federal/international animal health officials • Outreach/education of veterinary members • Meeting at WPX • Website updated weekly • Collaborate with NPB on research efforts and educational outreach to producers • Epidemiology efforts • Initial introduction survey • RRT participation

16. Veterinary Survey • Concern: How did this virus come into the U.S.? • Objective: Identify any risk factors potentially associated with the introduction of the PEDv into the U.S. swine herd • Survey designed by AASV, NPB, NPPC & USDA-CEAH • Administered by practitioners, data transferred to CEAH via link designed by FAZD at Texas A&M • Data analyzed by CEAH • Questionnaire examined > 100 variables • 25 case herds, 18 matched control herds

17. Survey Results • Only seven variables were considered significantly likely to have some association with the introduction of PEDv • These seven risk factors were associated with the process of feeding the animals. • Did not implicate any specific finished feed, feed ingredient, feed manufacturer or ingredient supplier.

18. Epidemiology – Observational Study

19. Response • Development of 3 working groups • Biocontainment • How to limit spread off an infected premises • Biosecurity Transport • Review, modify, recommend biosecurity plans for transport, shows/exhibitions, producers • Packing Plant • Recommend biosecurity principles for packing plants, buying stations, etc • These working groups have developed a number of guides targeting biosecurity published on NPB website

20. Research • Pork Board -- $3 million for PEDv research • Rapid response to research call • Research objectives • Diagnosis • Pathogenesis • Environmental stability • Epidemiology • surveillance • Shortened timeline • 13 days to identify and initiate research projects • Progress updates every two weeks • Six month deadline

21. Research • NPB, NPPC and AASV funded a study by Dr. Jim Lowe to look at transmission in harvest plant lairage.

22. Lairage Study • Trailers do become contaminated at packing plants due in part to movement of drivers • The more contact that occurs, the higher the rate of contamination

23. One positive trailer in means 1.7 positive trailers at exit Courtesy Dr. Jim Lowe

24. Research • Dr. Matthew Turner surveyed cull sow buying stations in NC • Minimal biosecurity in place • Virus present, likely transmission occurring • Willingness on the part of the managers to make changes

25. Future research focus for PED • Funding: • NPB - $650,000 • AFIA - $100,000 • Genome Alberta - $500,000 • NGFA - $60,000 • Formation and duration of immunity after infection; What level of immunity is needed for full protection? • Can immunity be overwhelmed? • Continued development and implementation of surveillance strategies for PED • Evaluate strategies for trailer disinfection

26. Feed as a possible vector • AASV survey identified feed as likely associated with the introduction • Feed has anecdotally been associated with outbreaks • Numerous bioassays on suspect feed and ingredients have been unable to confirm feed as a source

27. Feed Testing May-June, 2013:  NVSL tested feed, mineral and vitamin premixes and dried plasma samples.  Laboratory testing results (PCR) were negative except for dried plasma products. June, 2013:  NVSL conducted a bioassay using a vitamin premix and plasma.  The bioassay pigs did not show evidence of infection through testing of the feces and serology. July, 2013:  NVSL conducted a bioassay using dried plasma that was obtained from the blender.  The bioassay pigs did not show evidence of infection through testing of the feces and serology. Feb., 2014:  NVSL tested dried plasma from the manufacturer.  The samples were positive utilizing the real time PCR assay, and confirmatory testing is being conducted utilizing the nested PCR. March, 2014:  The bioassay for the last group of plasma samples is currently on test. 

28. Feed as a possible vector • Private research– has been able to transmit PEDv via feed to naïve pigs • Canada achieved a positive bioassay using spray dried porcine blood plasma but not feed pellets

29. Educational Outreach • AASV.org • Pork.org

30. Guidelines for Diagnosis of PED Virus • Lab diagnosis needed for determining site status • Managing biosecurity or biocontainment • Specifics of specimen collection • Feces • Oral fluids

31. PED Biosecurity Guidelines

32. PED Biosecurity Guidelines

33. Current Statusas of 06/07/14 Courtesy of NAHLN

34. Courtesy of NAHLN

36. Canadian Experience • January 23 – PEDv confirmed in Ontario • February – CFIA announces PCR positive feed • Positive bioassay with U.S. origin porcine blood plasma • Negative feed bioassay • Has since spread to multiple farms in Ontario and one each in Quebec, Manitoba, and PEI

37. What We’ve Learned • Although similar to TGE, PEDv is a different bug • More active in warmer environments • More difficult to control in a sow herd • Clinical picture can be more severe • Apparently no cross protection with TGE or PRCV • Huge amounts of virus are present • Holes in our defense layers – obviously exist but hard to identify • Biosecurity at all levels should be evaluated • Particular emphasis on transport, packing plants

38. What We’ve Learned • VDLs responded quickly but challenges with ability to communicate effectively • Tools exist today to facilitate this communication • FAZD has done an excellent job working with industry to facilitate the transfer of information • VDLs and NAHLN have stepped up to try to provide weekly data on new cases but… • Without PINs the data is suspect • Current mechanism is too labor intensive and archaic

39. What We’ve Learned • The use and ability to capture PINs would significantly improve data sharing • Challenges exist with defining roles government and industry with transboundary diseases • We are seeing “rebreaks” in 30 – 40% of herds • Swine Deltacoronavirus introduction???

40. Swine Deltacoronavirus • Clinically looks like TGE/PED but tests negative • Differential PCR available • 1st seen in Hong Kong in 2012 • Identified in Ohio in February • Identified in Canada in March

41. PDCoV Results (as of week ending June 7, 2014) Courtesy of NAHLN

42. Acknowledgements • Dr. Matt Ackerman – Swine Vet Services • Dr. Rodger Main – ISU VDL • Dr. Brian McCluskey – USDA CEAH