PEDV Update: Biosecurity & Disease Management

Considerations

R.B. Baker DVM, MSIowa Pork Industry Center

College of Veterinary MedicineIowa State University

Iowa Pork Congress 1/22/14

Talk Focus• Brief review of our advancing

knowledge –The PED virus in our herds–Farm Biosecurity Methods–Other biosecurity areas–Disease Management

– Resources: www.pork.org/pedv

Porcine Epidemic Diarrhea Virus

• A coronavirus similar to TGE virus

• Like TGE - high mortality in suckling

piglets (30-100%) “TGE on steroids”

• Never been in the U.S. before

• First observed in England 1971

Porcine Epidemic Diarrhea Virus

• PED is primarily spread by the fecal-

oral route

• Incubation is very short: 12-36 hours

• Vomiting and diarrhea in all ages

• PEDV only infects pigs

Porcine Epidemic Diarrhea Virus

• Elimination similar to TGE programs

– reported successful – takes longer (90days)

– Failures are reported but little data

• In single site continuous flow farms the virus often becomes endemic

• A generation II vaccine is on the market

Differential Diagnosis • Viral gastroenteritis – the PED virus is similar to, but

distinct from Transmissible Gastroenteritis Virus (TGEV).

• Porcine rotavirus groups A and B are also major causes in viral enteric diseases of piglets with similar clinical presentation.

• Bacterial gastroenteritis – Clostridium spp, E. coli, Salmonella spp, Brachyspira spp, Ileitis

• Parasitic gastroenteritis – Coccidia, Cryptosporidium, Nematodes.

Keeping it out• Biosecurity Challenges–Fecal Oral Routes are Numerous• Pigs (Isolation of new stock) • Pig Trailers & Truck Drivers –Rendering, Slaughter, Cull Sows etc.

• Feed Trucks and Drivers • Pig handling equipment – cut boards

etc. • Employees – hands, shoes, clothing

Keeping it out–Manure handling equipment and operators– Service personnel–Water supply– Tools – Supplies– Any fecal contaminated object that enters

the farm and contacts a pig

• Winter weather greatly enhances virus spread

Bio-Exclusion Considerations

Pest/WildlifeControl

Water

Feed

Pig handling equipment

Farm Biosecurity Clothing, boots,

hands – employees and Service

Supplies & Product

Deliveries

Transportation

Rendering & Culls

Tools/Equipment

Replacements

Aerosol – weather

Daily Biosecurity Priorities

Bio-Exclusion Considerations

• Limiting traffic (people and equipment) onto the farm,

• Thoroughly cleaning and disinfecting anything coming onto the farm including personal items

• Enforcing downtime requirements and maintaining a log of visitors

• Manure handlers should be careful not to track the virus between herds on their person, equipment or vehicles.

Disinfectants ?

Bio-Exclusion Considerations

• Establish practical barriers – “clean/dirty” concept.– Load-in/out– Feed deliveries– Service personnel– Supply deliveries– You if you deliver pigs to slaughter, haul to

other sites, and if you visit where other pig people go!!!

Daily Biosecurity Priorities

Bio-Exclusion Considerations• Taking care when disposing of dead stock

particularly if using a communal disposal method

• Isolating newly arriving animals and continuing vet to vet discussions about animal health at the herd of origin. Pre-entry testing For PEDV in the isolation

• Showering into the facility where practical and changing into clean boots and coveralls

• Shower out protects other producers

Bio-Exclusion Considerations• When entering a non-shower facility wash

hands or wear disposable gloves and wear site boots and coveralls or new disposables

• Inspect all transport vehicles before they back up to the load-out

• Take extreme caution with boots, clothing, haul trailer, truck, cutting boards and other loading equipment after visiting a slaughter or cull facility

• Avoid visiting where other producers may frequent without biosecurity precautions

Bio-Exclusion Considerations• Require that farm employees shower

back in when checking feed bins or check bins before showering-in at start of day

• Proactively plan feed delivery routes • Ideally, trucks should be able to unload

feed without entering site – outside the site fence

• Invoices should be left in mailbox at entry to farm

Daily Biosecurity Priorities

Bio-Exclusion Considerations

• Feed Drivers should keep a log of previous history of deliveries to other farms

• Ask your commercial feed supplier for a copy of their last biosecurity audit– Encourage them to develop one

Pig Transport Biosecurity

• Historically, transport was often incriminated in the spread of many infectious diseases – PRRS virus– Porcine circovirus– Transmissible Gastroenteritis Virus (TGE)– Salmonella and E. coli– Mycoplasma – Streptococcus suis and Haemophilus parasuis – Foreign Animal Diseases – FMD, CSF, ASF, others– Now PEDV

Pig Transport Biosecurity

• Next to the pig – transportation equipment has always been the greatest risk for disease agent dissemination and new disease introduction in the pig industry!

Pig Transportation

• Much of PEDV spread since the earliest cases has been associated with pig transport but not all

• Contaminated trailers, the tractors, and drivers are all high risk after visiting a cull sow buying station, truck washes or slaughter plant

Biosecurity and the transport driver

• The driver can be a significant cross or re-contamination risk– Tractor cabs should always be cleaned,

disinfected, and dried before the next haul– Drivers should carry clean clothing and boots for

each stop including the truck wash. – When entering the truck wash drivers should

shed outer wear (boots and coveralls) before entering the clean zone of the wash

Transport sanitization summary

1. Truck wash personnel, and drivers must be held accountable for deviations in standard operation procedures

2. Remove all bedding and visible organic matter during the scrape and flush step

3. Wash with hot water and detergent4. Disinfect with a field proven disinfectant5. Inspect 6. Repeat the wash and disinfection process if necessary7. Dry or superheat (160° F for 10 minutes) 8. Monitor the process

The AP Bio-DryTruck and trailer are heated 160 for 10 minutes or 120 for 20 minutes

Daily Biosecurity Priorities

Biosecurity is effective against PEDV!

BIOSECURITY

THINK!!

Elimination

• First Step has been early weaning off site

• Immediate feedback of infected material to the breeding herd

• Herd closure

Source: Geiger J.O., Connor, J.F. Porcine Epidemic Diarrhea, Diagnosis, and Elimination. www.aasv.org, accessed 11/10/13.

Elimination• If Possible:• All replacement gilts necessary for a period of

four to six months should be in the farm during the feedback exposure period

• Sentinel animals are best to determine if the virus has been eliminated prior to resumption of replacement flow (introduction of naïve animals)

Feedback protocols are like those for TGEV

• Consist of fecal material and/or the intestinal tracts (viscera) from infected / scouring piglets

• Process the viscera through a garbage disposal/blender etc. to macerate thoroughly

• Cold water may be used to extend/carry the feedback material– The virus is temperature sensitive – warm, hot, or

chlorinated water should be avoidedSource: Geiger J.O., Connor, J.F. Porcine Epidemic Diarrhea, Diagnosis, and Elimination. www.aasv.org, accessed 11/10/13.

What About Vaccine

• One on the market

• Several in the works

• Many in Asia

Impact on price of live hogs “Worst case scenario”

• Assuming a Price Flexibility of 2.37 and a reduction in supply of 7.7%

• Market hog prices would rise by7.7% * 2.37 = 18.25%

(Up $16.42 from $90 to 106.42)

(Provided by Dr. Derald Holtkamp)

Thank you