Transcript Update on PEDV

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
7
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 postchallenge
• Pigs, in general, appear to stop shedding virus by 35 days postinfection
• *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.
Survival of PEDV in Drinking and
Recycled Water
• Drinking Water:
– By rRT-PCR, PEDV RNA was detected for >7 weeks.
– Bioassay results show that PEDV was infectious for 2
weeks.
– TGEV was also infectious for 7 weeks.
• Recycled Water:
– By rRT-PCR, PEDV RNA was detected for >7 weeks.
– Bioassay results show that PEDV was infectious for 1
week.
– TGEV was infectious for 7 weeks.
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:
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
6.
Provide a barrier between you and the plant (boots/coveralls)
Change your clothes/footwear before going into your farm
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
31
PEDV Manure Hauling Guidelines
32
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!
[email protected]
515-223-2791