PEDv Pork Management Conference June 19, 2014 Carthage Veterinary Service, Ltd. [email protected].

PEDvPork Management Conference

June 19, 2014Carthage Veterinary Service, [email protected]

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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.