Biosecurity of PRRS - Back to Basics - Jim McKean, D.V.M., M.S., J.D., Iowa State University, from the 2012 World Pork Expo, June 6-8, Des Moines, Iowa, USA.

1. James D. McKean, DVM, JD
Associate Director
Iowa Pork Industry Center
Iowa State University
x2mckean@iastate.edu

2.  Definition: Steps/processes for disease control
 Bio – exclusion = external
 Bio – containment = internal
 Bio – management = internal
 Each pathogen class requires specific steps
 Work to MINIMIZE opportunities for spread
 Biosecurity -“cost” to business –layer protection
 Not all risk can be eliminated!
 MUST BE REASONABLE, ENFORCABLE and
APPROPRIATE TO IDENTIFIED RISKS
2

3.  Reduce impacts of external factors
 Animal isolation – observation and testing
 Limit human entry or pig contact
 Shower or hand washing as barrier
 Changes in clothing/footwear for entry
 Wildlife/rodent, bird and insect control
 Transport sanitation – clean, dry, disinfect
 Load-out – prevent animal/people entry

4.  Organisms to be excluded – not equal
 viruses more difficult than bacteria
 survivability on fomites – variable
 Required compliance by staff/visitors
 Area aerosol transmission potentials
 Area wildlife/rodent control
 Use of commercial hauliers for transport

5.  Routes of introduction
 Pig-to-pig
 Pig contact – common air space
 Pig fluids – manure, saliva, semen
 Indirect contamination
 Best carried in cool/cold, moist environment
 Humans as carriers – mechanical
 Fomites as carriers – including transports
 Other animals as carriers
 Aerosol spread – controlled by local conditions

6.  Clean vehicles only
 Driver requirements
(clean/dirty areas)
 Don’t cross paths
with internal traffic
 Always enforced

7.  Source – shedding pig population nearby
 Heavy shedding episode(s)
 Winds in right direction at same time
 Infective dose presented to naïve pigs
 Environmental facilitators
 Cool/cold temperature, high moisture
 Light breeze and overcast (reduced UV)
 Topographical considerations – range limits
 Trees and other objects break plume
 Water and flat surfaces extend range

8.  Risk is proportionate to area pig density
 Risks from movement of infected pigs
 What other steps have been instituted
 Pig/pig product introduction practices
 People controls
 Blockage for external transport risks
 Costs vs. benefits
 Likelihood of infection – area knowledge
 Initial costs and annual maintenance
 Building adaptability – materials for use

9.  Risk based decision – area specific??
 Past infection history in area/unit
 Impact of infection vs. cost of implementation
 Type of operation – seedstock vs. finishing
 Financial resources available vs. other needs
 Are all other “layers” in biosecurity effective
 If not, consider lesser cost options first
 Be committed to compliance at all levels
 Transports are high risk = load–out protection
 “What keeps you up at night in current state”?

10. Thank you for your
attention