Post on 15-Feb-2017
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Outbreak Investigation Program:A Systematic Approach to PRRS Outbreak Investigations
Kimberlee Gerardy
2015 North American PRRS Symposium
December 6th, 2015Chicago, IL
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
PRRSV Research Focuses on Two Areas
1. How do we return to baseline productivity faster after a break?
2. How do we keep PRRSV out?– 20 - 40% breeding herds have outbreaks annually (Swine
Health Monitoring Project, November 13, 2015)
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Outbreak Investigation Program• Pilot project was developed in 2013 through funding
by the Iowa Pork Producers Association (Checkoff $)
• Work with PRRS Regional Control Projects in Iowa– Share PRRSV history and production data for aggregate
analysis– Investigate PRRS outbreaks within the project
• 29 breeding herds currently enrolled in the pilot
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Objectives• Enhance knowledge of PRRSV spread and
prevention by investigating outbreaks in a timely, efficient, and uniform manner
• Determine most common gaps in biosecurity that may have lead to PRRSV introduction
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Methods: Standard Outbreak Investigation Form
• Background / Demographic Info– PRRSV History– Herd Characteristics– Premise Characteristics– Current Outbreak
• Questions on a set of risk events known to happen on farm and associated carrying agents
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Methods: Risk Events• Swine Movements– Semen– Gilts– Culls– Weaned Pigs
• Vehicles / Deliveries– Dead disposal– Feed– Propane / fuel– Garbage– Tools / Supplies
• People Movement– On-farm employees– Repair inside / outside barns– Other visitors (vets, vendors,
etc)• Pork / food product entry• Manure Removal• Other Animals• Air / Water
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Methods: Investigation• Interview– Veterinary outbreak facilitators– Herd veterinarians– Farm personnel
• Investigation Period: 4 weeks preceding the suspected onset
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Methods: Written Report• Identifies the likelihood
that each event was responsible for PRRSV introduction– Low– Medium– High
• Recommendations for biosecurity improvements
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Methods: Assignment of Risk Ratings
• Risk events are paired with multiple carrying agents
• Semen Entry– Semen– Semen packaging &
container(s)– Semen courier– Semen delivery vehicle
• Risk rating determined by:– Frequency of event
– Likelihood that a carrying agent is contaminated with PRRSV
– Likelihood that PRRSV gets from carrying agent to pigs in the herd
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Farms Investigated• 8 outbreak investigations between Jan 2015 – Aug 2015– All independent farrow-to-wean farms
Characteristic Farm 1 Farm 2 Farm 3 Farm 4 Farm 5 Farm 6 Farm 7 Farm 8Herd Size
(# sows) 670 1200 550 600 850 1085 1200 650
PRRSV Isolate 1-26-2 1-26-2 1-26-2 1-7-4 1-7-4 1-4-4 1-7-4 1-4-4
# Swine Sites within
5 Miles15 27 28 24 38 10 27 32
# PRRSV Outbreaks in Last 5
Years2 3 2 3 1 1 4 3
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Frequency of Risk EventsRisk Event Min Max Average (%)
Swine Movement
7 25 17 (9%)
Vehicles / Deliveries
9 39 17 (9%)
People Movement
42 114 91 (50%)
Pork / Food Entry
0 112 56 (31%)
Manure Removal
0 1 0.1 (<1%)
Total Risk Events
84 258 181.1
Large Farm Average44 31
330 282 3
690
Data from 8 medium sized (~850 sow) breeding herds
Data from 5 large (4500 sow)
breeding herds
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Events Rated High or Medium Risk for PRRSV Introduction
Cull So
ws
Feed
Delive
rieis
On-Farm
Emplo
yees
Dead R
emov
al
Repair
Insid
e Barn
sSe
men
New Su
pplie
s
Transf
erred
Supp
lies
Air/W
ater
Replac
emen
t Gilts
Other V
isitors
Weane
d Pigs
Manure
equip
ment /
pers.
..
Repair
Outside
Barns
012345678
1 1
4
1 1 1 1
42
4
1 1
5 4
3
2 2 1
# T
imes
Ran
ked
Hig
h or
Med
Ris
k
High Risk
Medium Risk
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
On-Farm Employees: Biosecurity Gaps & Connections
• Most frequent event on-farm
• Employees did not always practice downtime
• Sow farm employees worked at other swine sites or in other aspects of swine production (i.e. feed mills, market hog transport, etc.)
• Sanitation procedures were relaxed for employees that needed to exit and re-enter sow unit on the same day
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Cull Sow Movement: Biosecurity Gaps & Connections
• Cull sow transport was normally contracted non-exclusively to a 3rd party
• Trucks / trailers hauled multiple types of swine with no or unknown sanitation procedures
• Cull sow drivers and on-farm employees rarely observed lines of separation
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Feed Delivery: Biosecurity Gaps & Connections
• Feed mill biosecurity practices were highly variable
• Feed mill was located on a PRRS positive sow farm
• Feed mill equipment was shared with compost equipment in 3 outbreaks
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Operational Connections• Repairmen and their equipment worked at multiple
swine sites and did not practice downtime between the positive and negative sites
Farm A
Farm B
Farm C
Farm B
Farm C
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Conclusions• Timely identification of gaps in biosecurity– Identify most cost-effective biosecurity measures for the producer
• Immediate feedback after an outbreak
• Applicable to other endemic and emerging diseases– PEDV– Senecavirus A (SVA)
• People were high risk– Improved communication among personnel was needed– Additional layers of biosecurity were needed
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Acknowledgements• Iowa Pork Producers
Association• Iowa State University
Faculty and Staff– Derald Holtkamp– Christine Mowrer– Abbey Canon– SMEC
• SVIP Interns– Cassandra Fitzgerald and
Allysa Koethe
• Regional Project Coordinators– Cindy Gentz– Sonya Maas– Shamus Brown
• Producers and veterinarians of farms investigated
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Questions?
IOWA STATE UNIVERSITYVeterinary Diagnostic and Production Animal Medicine
Introduction of pathogens into a herd is the result of a series of “events” and “failures”
Carrying agent enters farm?
NoNo Risk
YesCarrying agent is
contaminated w/infectious pathogen?
NoNoRisk
Yes
Pathogen gets from carrying
agent to pigs in herd? Herd is
infected
NoRisk
NoYes
The 2015 North American PRRS Symposium wishes to thank the following sponsors for their generous
support: