Porcine Epidemic Diarrhea Virus

Transcription

1 Porcine Epidemic Diarrhea Virus (PEDV) Miles Beaudin

2 Current Status of Infection

3 PEDV Porcine Epidemic Diarrhea Virus Is not Zoonotic Which means that it does not affect people or other animals Is not a food safety concern Is not a new disease PEDv looks like TGEv

4 Pathogenesis The pathogenesis of a disease is the mechanism that causes the disease. The term can also describe the origin and development of the disease and whether it is acute, chronic or recurrent. The types of pathogenesis include microbial infection, inflammation, malignancy and tissue breakdown. Replicates in the enterocytes on villi and the small intestine. Degeneration/necrosis of enterocytes

5 Subtitle Bullet Bullet A)Litter of pigs infected with this virus, showing watery diarrhea and emaciated bodies. B) Emaciated piglet with yellow, water-like feces. C)Yellow and white vomitus from sucking piglet. D)Thin-walled intestinal structure with light yellow water-like content. E)Congestion in the small intestinal wall and intestinal villi; shedded epithelial cells from the intestinal villus. F)Degeneration, necrosis, and shedding/peeling of cells of the intestinal villi

6 The intestinal villi from a normal neonatal pig. Note that the villi are very long (black arrow) with large surface area to absorb nutrients and water. The crypts are where new cells are produce which will eventually slide up and replace the cells on the villi. Villi are long, covered with absorptive epithelium (arrow)

7 PED infection in a neonatal pig. The brown staining is infected cells lining the villi in a piglet roughly 8 hours after infection. All of the brown cells will die, releasing billions of virus particles to infect more cells and more pigs. Villi are covered with infected epithelial cells stained brown Crypt epithelium is spared and will be the source of new cell growth

8 Pathology Dehydration Intestine filled with yellow fluid.

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10 Sow and Piglets

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15 Nursery

16 Nursery

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18 Nursery

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20 Nursery

21 Growing Pigs Extensive necrosis of back muscles. Microscopically, villi in the small intestine of piglets are atrophic (degeneration/decrease). Atrophic=A wasting away of the body, from the defective nutrition.

22 Gross Signs Growing and Breeding Swine Gross Signs Growing and Breeding Swine Feeders, finishers and adult swine have Diarrhea; much more subtle than TGE May move more slowly than TGE Low prevalence of vomiting Depression Anorexia Signs of abdominal pain Sows Severe Diarrhea Morbidity may be high; affected animals are quite sick Mortality is rare; occasional sudden death

23 Clinical Signs Sows Sows were fevered, lethargic and scouring during late gestation or 2-3 days before farrowing Bullet Bullet

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26 Clinical Signs Sows Mastitis of sows contribute to high piglet mortality

27 Clinical Signs Sows

28 Risks Of Introduction Herd or System Transportation Dead Removal/Disposal Gilts People Feed Supplies

29 Cross Contamination Fecal Mater-Risk Areas Transportation Highest risk activity for movement of PED From processing and cull buying stations back to sites Truck Trailer Fomites (object or substance capable of carrying infectious organisms, such as germs or parasites, and hence transferring them from one individual to another. Skin cells, hair, clothing, and bedding are common hospital sources of contamination.) Boots, clothing sort panes, transporter Mortality disposal-rendering Contract Washers, Manure pumpers

30 Risk Reduction of Fecal-Oral Spread Transportation Dedicated Trailers Cull sows Market pigs Premarket pigs weaners

31 Virus is heat sensitive Virus Any thermal processing method is going to reduce infectivity such as pelleting. Sensitive to drying

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33 Reduce the Risk of Fecal-Oral Spread Transportation 1. All trailers are washed after movement 2. Wash, dry, disinfect all transport 3. Dry-increase temperatures to 140 degrees F for 20 minutes 4. Survives at 122 degrees F but not 140 degrees

34 Reduce the Risk of Fecal-Oral Spread Transportation Truck wash sanitation 3 rd party audits truck wash Trailer inspection with Pass/Fail Wash floor between trailers Disinfect at end of day and dry Boots, clothing, hose, wand sanitation Transporter s cab and supplies inspected

35 Reduce the Risk of Fecal-Oral Spread Loading/Unloading Staff Loading Establish a clean/dirty line from barn to the chute. Dedicated boots and coveralls in chute area Use plastic boots After Completion of Load - Wash and disinfect the chute

36 Clean/Dirty Line

37 Reduce the Risk of Fecal-Oral Spread Dead Disposal Review disposal procedures Rendering Risky activity No cross over traffic Separate drive ways Moves off site Equipment to transport dead pigs is washed after dropping at rendering site.

38 Reduce the Risk of Fecal-Oral Spread Isolation/Quarantine All replacement gilts are quarantined a minimum of 28 days Careful observation of signs of diarrhea Diagnostics testing performed if any signs of observed.

39 Feedback Material Formulation Piglet age not more than 5 days Only small intestine Take out put in plastic bag KEEP ON ICE 1 set of intestine per 10 sows 1 set per 250 ml fresh milk or Non chlorine water

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42 Results Diarrhea and mortality were not prevented in litter of sows that received feedback 1-2 weeks before farrowing. Antibiotics, electrolytes, sow milk replacer and colostrum replacer were of no help in controlling PED

43 Breed to Wean What to do now Walk rows twice a day Mark each sow when clinical signs appear (diarrhea, vomiting, anorexia, fever)

44 What to do now Wean to finish -Walk barns and pens twice a day -Mark each animal when clinical signs appear (diarrhea)

45 Reality If a packer was to get PEDv 1 out of every 10 trucks that back up to that facility would contract PEDv!