In-Depth Outbreak Investigation

Dyneah M. Classen, DVMCarthage Veterinary Service, Ltd.303 North Second StreetPO Box 220 Carthage, IL 62321www.hogvet.comPhone: (217) 357-2811

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Outbreak Investigation

1. Review the check list 2. Preliminary Report3. Map of the production area4. Have a brief conference call prior to the face-

to-face5. Schedule a face-to-face interview and tour of

the production area/farm6. Report

• Conclusions and Summarize Interview

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Preliminary Report

• Acute PEDv outbreak on Wednesday, April 1, 2015– Starting in Unit 1

• Laboratory confirmed PEDv original strain• All clinical signs began in farrowing

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Preliminary Report

Health Status• PRRS LVI off-site replacement gilts• Mycoplasma vaccinated• APP negative• PEDv negative

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Conference Call

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Preliminary Report• Production system consisting of 9 Units.

– 1 internal multiplier– 1 nursery– 1 GDU– 5 farrow-to-wean – 1 finisher

• Parity segregated system– Gilts are bred and farrowed at one unit then moved as sows to the

other• Operates own feed mill• Farm dedicated trailers• Internal truckwash

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Map of the Production Area

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Preliminary Report

• All employees (farm and feed mill) use an exchange site – Employees change from street clothing to

provided clothing– Food items are exchanged into plastic bag

provided– Leave personal vehicle in the dedicated parking lot

and take farm vehicles to each Unit.

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Rapid Response Outbreak Investigation FormOutline

1. Introduction 2. Site (and Flow, Production System) Summary and History of Past Outbreaks and

Pathogen Elimination Projects (Last 5 Years) 3. Description of Current Outbreak 4. Evaluation of Risks for How the Virus Entered the Herd

a. Characteristics of the premises, herd and surrounding area b. Maps of Production Site (from Google Earth or Mapquest) c. Maps of Surrounding Area (from Google Earth or Mapquest) d. Density of pigs in surrounding area e. Risk events in x weeks prior to outbreak

i. Swine Movements 1. Semen delivered to farm 2. Breeding replacements entered into herd 3. Cull sows hauled from farm 4. Weaned pigs hauled from farm

ii. Vehicles/Deliveries 1. Rendering truck removes dead pigs from farm 2. Feed or feed ingredients delivered to farm 3. Propane and fuel delivered to farm 4. Garbage collection from farm 5. New or transferred tools and supplies delivered to farm 16

iii. People Movement 1. On-farm employees 2. Equipment repair service personnel, working inside barns 3. Equipment repair service personnel, working outside barns 4. Electrical, plumbing, veterinarian, vendors, visitors, and off-farm

production personnel iv. Pork/Food Product Entry

1. Pork and other food products v. Manure Removal from Farm

vi. Entry of Other Animals 1. Birds 2. Rodents 3. Wild, Non-rodent Mammals 4. Domestic Animals 5. Insects

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Investigation

• Acute PEDv outbreak starting in Unit 1• Moved parity one sows to 2 other Units• What is different about Multiplier Unit?

– It remained PEDv negative.

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Investigation

Swine MovementsVehicles DeliveriesPeople MovementsManure RemovalEntry of Other Animals

(pest)Air and Water Entry

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Investigation

• Meeting in the herd veterinarian office• Tour of the production area• Tour of the feed mill• Meeting in with the production team in the

office

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Summary• Animal movement highly likely to have moved

PEDv• Mortalities are collected at a central location

for disposal – no rendering• Issues at the exchange site with vehicle usage,

located across the road to the Unit 1 outbreak• People movement/exchange vehicle usage to

the spread of PEDv through the production system

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Summary

• Maintenance equipment is kept separate for each Unit

• Real time ultrasound is shared between sites

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Summary

• Feed mill did have birds, but the overall biosecurity procedure were good. – Local ingredients only on “blue bird” days.– Own feed trucks– Delivery of feed ingredients to a box truck and

held for 30 days prior to use– No animal products are used in feed– No Asian sourced trace minerals

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Summary

• Dedicated truck wash• Transfer station for cull sows and wean pigs• Manure removal is done by production system

employees and equipment is owned by employees

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Summary

• Birds did have access to the feed mill and several of the older farrow-to-wean units

• Migratory Fowl (Snow Geese and Canada Geese) populations in fields surrounding the farms

• Units are not filtered• Water sourced from

individual wells

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Conclusions:1. Based on non-published data from Carthage Innovative Swine

Solutions, LLC (CISS) on environmental swabs collected Fall 2013 – Winter 2014 the PEDv virus can be detected inside the farm offices, shower and foyer areas 3 days prior to clinical signs exhibited by the animals. a. This would put the introduction of PEDv into Unit 1 between March

25, 2015 and March 29, 2015.

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2. At this time I could not determine an entry point for PEDv into the index herd Unit 1. a. Propane delivery to Unit 1 on March 27, 2015 would fit

this timeline. i. However the thoroughness of the production team makes this

seem the unlikely event. ii. The Propane delivery truck was washed and disinfected at the

Production Managers home prior to going to Unit 1.

3. Most likely explanation of PEDv movement to Unit 27 and Unit 28 is due to sow movement on April 1st and March 30th respectively from Unit 1.

Conclusions:

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4. The dedicated use of production system farm vehicles to a Unit appears questionable, especially over the weekends. a. Extensive swabbing conducted following an outbreak of

PEDv showed, the PEDv could be found in the employee shoes, vehicles, and personal items like cell phones.

i. Note in this system cell phones were not permitted in the farm, but may have been in the employees street clothing in the shower or pocket of the employee’s coat in the foyer.

5. Maintenance equipment was not permitted to be shared between Units, but the Real Time Ultrasound was. a. This is also a fomite that could have carried virus between

Units. b. Due to the lack of log/tracking

Conclusions:

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6. Unit 4 has significant differences from the other production system sow farm Units that may have decreased its risk of PEDv exposure. a. No onsite garbage dumpster for pick up. b. No FURST McNess product. c. No PRRS Live Virus Inoculation (LVI) material. d. No gilt introduction as it’s an internal multiplication.e. Low human impact – only two employees that are related and live in

the same home.

Conclusions:

Thank You