Update on PED Research

Lisa Becton, DVM, MS, DACVPM

Dir. Swine Health Information & Research

National Pork Board

History of PEDV • PEDV was confirmed in the US on May 16th, 2013 by

diagnostic tests at the USDA National Veterinary Services Laboratory (NVSL) in Ames, IA

– Found in multiple farms simultaneously and then additional farms diagnosed positive potentially from lateral spread

• In May of 2013, PEDV was new to the US and no existing information regarding basics of disease pathogenicity, virulence, epidemiology etc., existed.

• To address this urgent need, the Board has since approved >$2 million for use for research of PEDV. And, just recently approved an additional $886,500 for continued research focus.

Current Status of PEDV

• PEDV continues to be a major health challenge for U.S.

producers into 2014

• Since it was first diagnosed in May of 2013, there have

been a total of >6804 cases reported:

– CASE reports are different than SITE reports.

– 30 states (VA most recent state with positive case)

– Data can be found at www.aasv.org

National Pork Board Focus

• Research focus - New virus therefore needed research on PEDV and impact for US producers

• Development and communication of producer information/resources

• Containment/management strategies– Work with USDA/stakeholders and develop next steps

for emerging disease response

– Rapid Response Team pilot/Surveillance activities

PEDV Research Efforts

Development of Research Priorities

• *Swine Health Committee – producers,

veterinarians, advisors (university,

government, industry)

• PED Strategic Task Force

• Input from AASV and NPPC membership

• State Pork Associations input

PEDV Research Priorities

June 2013 Initial Research Priorities:

Needed to get answers quickly! (<6months)

Basic understanding of the characteristics and pathogenesis of PEDV

Development & validation of diagnostic tests (antigen and antibody)

Environmental stability on various surfaces and substrates and

effectiveness of sanitation efforts

Epidemiology of the disease

Funded 8 proposals early June for 2013 – “basics”

research for PEDV

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PEDV Research for Fall 2013

• Understanding sow immunity was high priority for the fall call and the Committee funded 3 proposals addressing multiple aspects of sow immunity:– Duration of immunity; Optimizing feedback protocols;

Diagnostic tests to assess sow and piglet immunity to PEDV

• Other areas of concern and focus for fall 2013: – Assessment of feed as a source of viable/infective virus

– Ability of disinfectants to denature PEDV

What we now know about the “basics” of PEDV

“Basic knowledge” for PEDV:

• Clinical signs: diarrhea starts at 2-3 dpi & stops after 10 dpi

• Severity of disease is age dependent

• Virus shed (fecal) starts at 24-48 hrs & peaks at 5-6 days post-challenge

• Pigs, in general, appear to stop shedding virus by 35 days post-infection

• *Important to understand for clean-up and management post-outbreak – long-time between stop of shedding vs. clinical signs

• PEDV did not shed via the air in the aerosol in the lab setting when pigs were housed in the same room but with no other direct contact

Development and Support for Diagnostic

Tests

• Researchers have been able to develop a method to propagate the virus in cell culture**This step is critical for future diagnostic tests and for

vaccine development

• Development and validation of key diagnostic tests for PEDV: virus detection (PCR); exposure (ELISA); immunity (IFA/FFN)

• Sequencing the genome of PEDV – is it changing?

• Evaluate diagnostic tests that can look for more than one disease:

• TGE; PEDV; Rotatvirus

• Validate samples for PEDV – oral fluids (screening test); feed; environmental samples

Survival of PEDV in various materials/surfaces

• Fresh feces (humidity dependent)

– 14 days @ 104ºF & 122ºF; 7 days @ 140ºF

• Manure Slurry

– 14 days @ 77ºF; >28 day @ 39ºF and -4ºF

• Feed

– Dry feed: 1 week survival but not @ 2 weeks

– Slurry: PCR+ @ 28 days; no diarrhea in weeks 1-3

Survival of PEDV in various materials/surfaces

• Amount of virus needed for infection: LOW

– Virus is shed in very high amounts in piglets

• Metal surfaces

– Virus can be killed at 160 F for 10 minutes OR

maintaining them at room temperature (68 F) for

at least 7 days.

Analysis of the Risk Factors for the Spread

of PEDV

Study done through the Swine Health Monitoring Project:

http://www.cvm.umn.edu/sdec/SwineDiseases/pedv/index.htm

• NC Cluster:

Type of farm: Fw – Fin (48.8%) vs. individual site (31.6%)

Location of POS farm and risk of being infected

1 mile – 8.4

2 miles – 6.3

>3 miles – no Î risk

Other risks that are being evaluated include the increased frequency

of trash hauling, dead removal, animal movements etc.

Analysis of the Risk Factors for the

Spread of PEDV

• OK Cluster:

Analysis is suggestive of airborne spread due to location

of positives and wind direction

Additional research needs to be done to evaluate fully

• Swine Health Monitoring Project: 718 premises signed up

and project is ongoing and includes summaries from

additional research projects within the industry

• http://www.cvm.umn.edu/sdec/SwineDiseases/PEDV/index.htm (Morrison

and Goede)

Transportation Research

• Completed in June 2013, an initial survey performed at 7 market hog plants in the Midwest (Lowe et al.)

– 669 environmental samples collected and found PEDV

– “Swiffered” trucks at entry to a plant and at exit from the plant

• June 2013: Buying station survey in NC – 4 locations (Turner)

– Swabbed chutes and pigs

Results of Transportation Surveys

• Virus was found in all 7 plants, but not all plants were equally contaminated

• Virus was found in the NC buying stations both in the facilities and from animals with clinical diarrhea

• Transportation activities pose a real risk for the spread of PEDV!!– More contact time within plant is a high risk

– Cross-contamination between plant and farms occurs

– Vehicles can serve as transfer vector for PEDV

What we learned in 2013

1. PEDV is a fecal-oral spread disease

2. PEDV can survive a fairly long time in different conditions and temperatures –best in cold/damp conditions

3. Transportation is a big risk for spreading the virus. More contact between trailer and plant is associated with higher rates of PEDV spread.

4. The virus can be killed at high temps or over long time.

5. Limit or eliminate contact with areas that could be contaminated from other pigs: packing plant, cull markets, other farms:

Provide a barrier between you and the plant (boots/coveralls)

Change your clothes/footwear before going into your farm

6. Focus needs to continue to be on clean and disinfected equipment/supplies/trailers coming into your farm to limit PEDV spread

Removal of all organic material is critical!!!

Allow for downtime if at all possible

What do we still need to know?

Key Questions in 2014:

• How is sow immunity developed?

• How long does it last?

• How do we measure those levels?

• Are feed/feed systems an issue for PEDV spread?

• What is the best way to test feed/feed samples for PEDV?

• What steps can you take to make feed/feed systems safe?

PEDV Research Funded for 2014

• For the Spring call for proposals, the Committee

selected projects for funding focusing on:

– Validation of new diagnostic tests: continue to dig into

PEDV and start to look at immunity vs. just present or not

– Continuation of a surveillance project to monitor incidence

and track transmission

– Assessment of efficacy of disinfectant to denature proteins

and provide negative PCR result

Sow Immunity – What do we know?

• Sow immunity is developed for PEDV and can be measured by diagnostic testing

• Immunity does not appear to be as long-lived as assumed (NOT similar to TGE)

• New tests are being developed to assess protocols for developing immunity

PEDV Research For 2014

• Late fall, questions arose as to whether or not PEDV

can be transmitted via feed and research focus for

feed was a high priority for 2014.

• March 19th: Feed Consortium meeting in Iowa to

discuss immediate needs for feed research;

collaboration and $$ support by feed industry

• Additional research focus, collaboration and $$

leverage with Genome Alberta $500K on research

priority needs and focused RFP for PEDV

PED Feed RFP 2014

• Investigate effectiveness and cost of feed or feed ingredient treatments that could be used to mitigate viral survival.

• Develop a viral dose-infection curve showing viral dose by time and by temperature for both pelleted and milled feed.

• Develop diagnostic procedures for determining potential live virus contamination of feed or feedstuffs.

PED Feed RFP 2014

• Feed-focused research: the Swine Health Committee selected 8 proposals for funding:– Risk assessment of feed ingredient as potential to transmit

PEDV

– Evaluation of feedmills for risk of transmission

– Look at birds as a potential mechanism for spread

– Look at the impact of pelleting time/temp and other feed interventions on PEDV

– Look at alternatives to the current bioassay methods other than the live-pig model

– Additional support from the feed industry to help fund this critical research

• NGFA

• AFIA

• Cargill

• State Associations: IA, IL

PEDV/PDCoV Focus

• PDCoV assessment for research needs

– Worked with diagnostic labs on immediate needs for

research: capabilities, pathogenesis, diagnosis etc.

• PEDV research RFP – finalized to be posted

April 15th with proposals due April 22nd.

– Working with Genome Alberta on priorities and

funding resources

Animal-based Research for 2014

• Additional questions arose due to the identification of PDCoV and PEDV

• Focused on understanding more about PDCoV and pathogenesis in the pig

• Develop additional diagnostic tests specifically for PDCoV

Additional funded research

• The Committee funded 7 projects:– PEDV antibody-based diagnostic test improvement for evaluation of immunity in

milk, feces and serum

– PDCoV ELISA development

– Development of pseudotyped reporter viruses for detection and characterization of

neutralizing antibody response to PEDV and Deltacoronavirus

– Development of reagents and serological assays for Porcine Deltacoronavirus

(PDCoV)

– Development of pig oral fluid based virus neutralization assay and mucosal B cell

responses to PEDV: potential tools to monitor herd immune status

– The pathogenesis and characterization of porcine epidemic diarrhea virus (PEDV)

and porcine enteric deltacoronavirus (PdCoV) in neonatal gnotobiotic swine

– Determination of the sites of tissue localization, routes of viral shedding, duration

of virus carriage, kinetics of antibody response, and potential of aerosol

transmission of Porcine Deltacoronavirus (PDCoV) following inoculation of nursing

pigs

PEDV Research

• Information and

updates on funded

projects available at

www.pork.org/PED

Communication of Research Results

(All research information is posted at www.pork.org/PEDV )

• Wanted to provide producers with as close to “real time” results as possible

• Utilized PEDV specific site for all information

• Research updates available bi-weekly until project completion

Development of Producer Resources

• Objective: Put together the best people possible to provide recommendations to address PEDV biosecurity and biocontainment; develop key areas of focus, and utilize current knowledge of the virus

• PED Strategic Task Force

– Review, advise, guide

– Urgency

• PED Working Groups

• NPB Staff Communications

• Collaborative efforts – NPB/NPPC/AASV/SAHO/etc.: target respective audiences

PED Transportation Guidelines

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PEDV Manure Hauling Guidelines

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Other PED Resources

• Recommendations available for:

– Exhibit Organizer Biosecurity

– Exhibitor Biosecurity

– Positive in Breeding Herd

– Positive in Nursery/Grow-Finish

– Line of Separation

– Create Clean Crossing

– Additional resources…

Summary

• PEDV and PDCoV are emerging diseases of swine that have proven to be very costly to producers

• Cooperation and collaboration between all sectors of industry and government is a must

• Need to continue to focus efforts for collaboration and cooperation on key research questions for disease management and control

Thank you!

lbecton@pork.org

515-223-2791