Keeping disease off the farm.




    Scott Dee, Andrea Pitkin, Satoshi Otake, Simone Olivera, John Deen,
          Peter ...
SDEC partners

   Corporate members               Practice members
       PIC                             Pipestone Ve...
Topics

   1. How does PRRSV spread between farms?
       What is the role of aerosol transmission?


   2. How can we ...
How far can PRRSV and M hyo travel in the air?




PRRSV




                                                 4
M hyo




The Production Region Model: New way to
conduct applied research on PRRSV
   Justification
       Proof of kno...
Year 1

   Low


               120m


                      Source Population
                         PRRSV (+)
        ...
Results: Year 1
   High level (MERV 16 filter)
     No infection (0/26 replicates)




   Medium level (no filter)
    ...
Results: Year 2

   No infection in filtered facility
       0/13 replicates (MERV 16 filter)


   PRRSV and M hyo infe...
Results: Year 3

   No infection in either filtered facility
       0/13 replicates (MERV 14)
       0/13 replicates (a...
Weather conditions present on days
in which PRRSV was not present in air




Summary

   Production region model
       ...
Where do we go next?




Application of air filtration to the field

   AI centers
       (Reicks, Spronk, Ruen, et al.)...
Application of air filtration to the field

   Sow herds
       (Reicks, Spronk, Ruen, et al.)
           Bigger challe...
Characteristics of filtered and non-filtered farms

    Treatments (n=10)                  Controls (n=21)
    BH Inven...
Prevention of back drafting:
AP Double shutter




Cost of filtering a sow farm
Dependent upon
  1. type of filter
  2. ve...
Progress so far…
   Year 1: Sept 08-Aug 09              Year 2: Sept 09-Jan 10

   External virus introduction in     ...
Big Picture

   1. We now understand and can
    impact PRRSV transmission
    between farms.
     The risk of long dist...
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PDF: Dr. Scott Dee - Keeping Disease off the Farm

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PDF of Keeping Disease off the Farm - Dr. Scott Dee, University of Minnesota, from the Iowa Pork Congress, January 27-28, 2010, Des Moines, IA, USA.

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PDF: Dr. Scott Dee - Keeping Disease off the Farm

  1. 1. Keeping disease off the farm. Scott Dee, Andrea Pitkin, Satoshi Otake, Simone Olivera, John Deen, Peter Davies, Gordon Spronk, Darwin Reicks, Paul Ruen Disclosure and Acknowledgements  USDA NRI PRRS CAP 1 and 2  National Pork Board  MN Pork Board  MN Rapid Agricultural Response Fund  Boehringer-Ingelheim  Genetiporc  Preserve International  MN Veterinary Diagnostic Laboratory  Midwest Microtek  Filtration Systems, Inc.  Noveko,Int. 1
  2. 2. SDEC partners  Corporate members  Practice members  PIC  Pipestone Vet Clinic  Genetiporc  Fairmont Vet Clinic  Boehringer-Ingelheim  Swine Vet Center  Pfizer  Clinique Demeter  Novartis  Cannon Valley Vets  Noveko  Carthage Veterinary  Camfil Farr/Filtration Service Systems, Inc.  Japanese Assn of Swine Vets  Bayer Disclosure  I do not  Receive royalties or commissions on the sales of filters or filtration equipment.  Hold any patents on filtration inventions.  Have research contracts or consulting agreements/retainers with filtration/equipment companies. 2
  3. 3. Topics  1. How does PRRSV spread between farms?  What is the role of aerosol transmission?  2. How can we stop it?  What is the role of air filtration? Routes of PRRSV spread between farms Route Example Intervention Genetics Pigs, semen Quarantine & Test Fomites Boots, coveralls, Disinfection containers Personnel Hands Entry protocols Transport Contaminated Drying trailers Insects Mosquitoes, Screens, Houseflies insecticides Airborne Bioaerosols Filtration 3
  4. 4. How far can PRRSV and M hyo travel in the air? PRRSV 4
  5. 5. M hyo The Production Region Model: New way to conduct applied research on PRRSV  Justification  Proof of knowledge of the routes of spread and the efficacy of biosecurity protocols is essential before large scale disease eradication efforts can begin.  Objective  To develop a model of a swine production region that is endemically infected with PRRSV and M hyo and evaluate identified routes of transmission and protocols of biosecurity on a day-to-day basis.  Hypothesis  Controlling airborne spread of pathogens is essential for sustainable control and elimination of both agents.  Certain meteorological conditions will influence airborne spread. 5
  6. 6. Year 1 Low 120m Source Population PRRSV (+) MN-184 120m High Medium Definition of biosecurity levels Route High Medium Low Aerosols yes no no Insects yes yes no Transport yes yes no Fomites yes yes no Personnel yes yes no 6
  7. 7. Results: Year 1  High level (MERV 16 filter)  No infection (0/26 replicates)  Medium level (no filter)  8/26 (31%) replicates PRRSV (+)  All by air  Low level (no filter)  14/21 (66%) replicates PRRSV (+)  2/7 insects  7/7 fomites/personnel  5/7 air Year 2: Production Region Model Source Population PRRSV MN-184 M hyo 232 120 m Treatment Control 7
  8. 8. Results: Year 2  No infection in filtered facility  0/13 replicates (MERV 16 filter)  PRRSV and M hyo infection in non-filtered facility via the airborne route  6/13 replicates: PRRSV  7/13 replicates: M hyo Year 3: Production Region Model Source Population PRRSV MN-184 M hyo 232 120 m Treatmen Treatmen Control t t 1 2 8
  9. 9. Results: Year 3  No infection in either filtered facility  0/13 replicates (MERV 14)  0/13 replicates (antimicrobial)  PRRSV and M hyo infection in non-filtered facility via the airborne route  8/13 replicates: PRRSV  5/13 replicates: M hyo Weather conditions present on days in which PRRSV was present in air 9
  10. 10. Weather conditions present on days in which PRRSV was not present in air Summary  Production region model  1091 days, 4331 pigs and 22,512 samples  no infection of susceptible populations housed in filtered facilities independent of filter type.  53% infection rate in non-filtered facilities (PRRSV)  46% infection rate in non-filtered facilities (M hyo)  Under controlled conditions, filtration technology is flawless, independent of filter type. 10
  11. 11. Where do we go next? Application of air filtration to the field  AI centers  (Reicks, Spronk, Ruen, et al.)  3-4 years underway  Swine dense regions  Successful protection against multiple airborne pathogens well documented  Easy to install and manage 11
  12. 12. Application of air filtration to the field  Sow herds  (Reicks, Spronk, Ruen, et al.)  Bigger challenge  Larger buildings  More people  Greater turnover  Less emphasis on biosecurity vs. studs Current project  Project Participants:  UMN, SDSU PVC, FVC, SVC, Production systems  Objective:  To evaluate the efficacy of air filtration for reduction of external PRRSV introduction to large sow herds located in swine dense regions  Selection criteria:  > 2400 sows  > 3 external virus introductions over the past 4 years  > 4 pig sites within 4.7 km radius of candidate herd  Industry standard biosecurity  Design:  Sample size: 6 treatment herds, 18 controls  Duration of study: 4 years  Outcomes measured:  External virus introduction  Cost-benefit 12
  13. 13. Characteristics of filtered and non-filtered farms  Treatments (n=10)  Controls (n=21)  BH Inventory  BH Inventory  Mean = 2903 sows  Mean = 3378 sows  Range = 2402-3827  Range = 2506-5578  External virus introduction  External virus introduction  Mean = 1 every 13.1 mths  Mean = 1 every 12.8 mths  Range = 1 every 8-15 mths  Range = 1 every 11-13 mths  # sites within 4.7 km  Mean = 8  # sites within 4.7 km  Range = 4-17  Mean = 8  Range = 4-13 Attic installation of filter boxes 13
  14. 14. Prevention of back drafting: AP Double shutter Cost of filtering a sow farm Dependent upon 1. type of filter 2. ventilation system 3. necessary modifications to existing system extras  Examples from 4-3200 sow herds  Farm 1  $251/sow  Farm 2  $195/sow  Farms 3 and 4  $141/sow  Cost of a PRRS break: >$500,000/3200 sow herd  Prevention of 1 break pays for the system! 14
  15. 15. Progress so far…  Year 1: Sept 08-Aug 09  Year 2: Sept 09-Jan 10  External virus introduction in  External virus introduction in 0/5 treatment herds. 2/10 treatment herds.  External virus introduction in  Transport and personnel 15/21 control herds. breaches confirmed via diagnostic evidence and security camera tape  No evidence of filter failure  External virus introduction has been documented in 7/19 control herds. Lessons Learned  In the field, a comprehensive approach to PRRSV biosecurity is required.  The “human factor” is a major risk, no matter how intense the training.  Continuous auditing/oversight/monitoring is required  Due to the “human factor”, filters cannot be considered as “silver bullets” for controlling PRRS.  However it is impossible to prevent airborne spread in swine-dense regions without them. 15
  16. 16. Big Picture  1. We now understand and can impact PRRSV transmission between farms.  The risk of long distance airborne spread of PRRSV is real.  2. Filtration is an effective tool for control the spread of airborne diseases for farms in swine-dense regions.  3.For the first time in 20 years, we can consistently produce a PRRSV-free weaned pig. 16

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