Ontario appears to have turned the corner on Porcine
Epidemic Diarrhea virus, but the hog industry needs to remain on high
biosecurity alert.
The Ontario Pork Industry Council and the Ontario Swine
Health Advisory Board report that since the first outbreak at the end of
January, there have been 58 farms hit by the highly-infectious virus.
But there have been no new cases since April 30.
And some farms have cleaned up and are back in business.
These include two all-in all-out nurseries, one all-on
all-out finishing barn, one sow herd that has successfully eliminated Delta
coronavirus via herd depopulation and one sow herd that eliminated PED virus
via herd depopulation.
They say there are a number of nurseries and finisher sites
working on PED elimination over the next few months.
They are applying the ARC&E protocol they have developed
for the regional elimination of Porcine Reproductive and Respiratory Syndrome
(PRRS) virus.
That includes maps pin-pointing the location of outbreaks so
anyone nearby or with any type of contact with those places can be on high
alert for an outbreak. Tight biosecurity is essential, especially to make sure
no speck of manure can be carried from infected locations into hog barns.
Hog transportation remains the major concern.
The Ontario Pork Council is passing on this message from a
meeting of swine veterinarians in the United States:
- PED virus is highly infective with a
10-8 dilution of mucosal scrapings able to cause infection – this means
approximately one pencil eraser of diarrhea diluted in 130 cubic yards can still
cause infection, making fecal-oral the principle route of infection. As well,
infective PED has been found in fecal slurry after more than14 days at room
temperature. That means stringent clean
and disinfect protocols are essential.
- Analysis of number pigs weaned per week
suggests it takes six weeks on average to return to normal production at
farrowing sites
- The majority of protection to piglets
is expected to come for colostrum IgA antibodies; this is a passive immunity
and will quickly reduce after weaning. These antibodies do not protect against
infection with PED virus.
- Proximity to an infected site and size
of herd may be factors that impact the risk of PED infection.
- Control of PED is not the same as
elimination of PED and not eliminating the virus can result in the risk of
repeated outbreaks of clinical disease.
- PED elimination at sow sites should be
done in consultation with your veterinarian. Consideration of other disease
issues in the herd is essential before initiating an elimination program.
Work to date suggests the following actions are required to
eliminate PED at sow sites:
- loading with replacement animals.
- herd closure for a minimum of three months
(and perhaps as long as five months).
- infection of the entire herd through
feedback procedures.
- strict all in all out and
uni-directional flow of pigs and people.
- strict sanitation and McRebel protocols, which are posted on the OPIC website under PRRS toolkit.
- do not introduce negative replacement
animals until the flow is verified negative (testing and sentinels).
Evidence suggests PED is more highly transmissible than
PRRS, has a higher stability in the environment and shows lower levels of sow
immunity. However, duration of clinical signs is dramatically shorter.
