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Carthage Veterinary Clinic Hancock Veterinary Clinic
Carthage, ILSuzhou, China
Solutions for the Food Supply Chain
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Epidemic
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PEDv Worldwide
Beek, Vincent
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Genetics
Woo, et al. J. Virol. 2012
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PEDv
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Swine Deltacoronavirus (SDCoV)
• Non-PED coronavirus– Clinical signs similar to PED and TGE– 40% PWM for 2-3 weeks
• Described in Hong Kong - 2012• First case - June 5, 2013• Diagnostic capabilities– SDCv PCR– No serological testing
ADDL
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Woo, et al. J. Virol. 2012
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SDCoV
Woo, et al. J. Virol. 2012
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Porcine Deltacoronavirus Bioassay
• Nine - 14 day old piglets – Inoculated with PDCoV from field samples
• Euthanized on:– Day 2 post-infection (PI)– Day 4 PI– Day 6 PI
• Showed no evidence of enterocyte infection• Negative for PDCoV by RT-PCRUniversity of Minnesota
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Porcine Deltacoronavirus
Retrospective analysis• 30% positive rate on cases• Co-infection (PEDv, TGEv, RVA, RVB, RVC)– 78% positive for PEDv, RVA, RVB, and/or RVC– RVC positive >50% of the samples
• 4 complete genomes– US isolates - 99.8% similar– Chinese strain - 98.9% - 99.2% similar
University of Minnesota
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Outbreak Management
Day 0
• Wean down in age• Begin oral live virus exposure• +/- oral progestins
Day
1-5
• Aggressive oral live exposure
Day 6-14
• Euthanize all piglets born• SANITATION
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PEDv Impact
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PEDv Impact
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Euthanize pigs on Day 0 – 14 days
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22Courtesy of Dr. Jim Lowe
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Herd Eradication Management
• Aggressive sanitation– Double de-grease, Double wash, Double disinfect
rooms• 2 nights downtime• Wash sows prior to loading
– No carts, change shoe– Full McREBEL– Do not touch pigs till day 7– Wash gestation barns continuously– Wash hallways after every pig movement
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Antibody Response
ISU. Gimenez-Lirola. NPB #13-264
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Song, D. Park, B, Virus Genes, 2012
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SDSU. Clement. NPB #13-263
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SDSU. Clement. NPB #13-263
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Conditional Vaccine License
Harrisvaccines, Inc• June 16, 2014 approval• Qualifications:– Safety– Purity– Reasonable expectation of efficacy
• Long term – Modified Live Vaccine
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PRRS and PEDv Site Classification Guidelines
PEDv Site ClassificationI Infected and SheddingII Stable, Weaned pigs are negative for PEDvIII Provisionally NegativeIV Negative
PRRS Site Classification1 Positive Unstable
2v Positive stable, Ongoing exposure2 Positive Stable3 Provisionally Negative4 ELISA Negative
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What do we need to learn?
• Epidemiology– Watch Canada• Have they identified a key transmission route?• Feed risk
– Origin of viral introduction to the US• Herd stability/eradication– Poor immune response or viral load?– Vaccine development
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Canadian PEDv
62 cases in Ontario
Accessed on 06/16/2014. http://www.ontariopork.on.ca/ped/ComfirmedCases.aspx
Carthage Veterinary Service, Ltd
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PEDv – Late Finishing Infection
• Looseness observed 2 days prior to ADFI drop– 7 lb/day prior to break– 2 lb/day at peak - ~80% reduction 2-3 days
• ADG– Reduced 31% Day 0-7 post infection
• F/G– No significant difference
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PEDv – Late Finishing InfectionWater Intake– Depressed for 7 days
One positive trailer in means 1.7 positive trailers at exit
PlantContaminated
at entryContaminated
at PlantContamination
RatioA 2.25% 8.05% 3.58B 7.00% 4.30% 0.61C 10.84% 10.81% 1.00D 2.00% 0.00% 0.00E 14.56% 3.08% 0.62G 3.00% 1.03% 0.34
All 5.98% 4.31% 0.72
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Biosafety of Spray Dried Plasma Relative to PEDv
1. PEDv does not survive spray-drying
2. Experimentally inoculated spray-dried plasma loses infectivity by 7 days when stored at room temperature
3. Retained samples from Canadian lot of spray-dried porcine plasma and 2 other samples of PCR positive commercial spray-dried porcine plasma did not contain infective PED virus
1. FDA acquired samples of the specific lot were negative on bioassay
4. Weaned pigs fed a diet with 5% PCR positive spray-dried plasma for 14 days post weaning remained PEDv negative for the 21 day feeding periodAPC Tech Brief – April, 2014
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Biosafety of Spray Dried Plasma
• Additional Questions– Is the lab simulation of spray drying similar to the
actual process?– What is the sensitivity of the bioassay?– Does the lab strain of PEDv have the same survivability
to the field strain?– Do all spray dry plants use the same processing
parameters?– What is the variation in the plasma production process?– What are the QA/QC procedures involved?
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Working Group
Focusing on research, control, and contamination – 4 Priorities:
• To investigate the effectiveness and cost of treatments that could be used to mitigate the survival of PEDV and other viruses in feeds
• To conduct contamination risk assessments at all steps within the feed processing and delivery chain
• To develop a substitute for the currently used swine bioassay procedures
• To continue to investigate the risk of feed and other pathways for pathogen entry into the U.S.
