Alberta Pork and Alberta Agriculture and Forestry hosted a town hall teleconference on March 13 for over 150 producers and industry partners, related to the discovery and investigation of the porcine epidemic diarrhea (PED) virus in our province this year.
Alberta Pork continues to work closely with Alberta Agriculture and Forestry to prevent the disease from spreading further and fully investigate the source of the outbreaks. At this time, no sources have been found, and any possible connection between the outbreaks remains uncertain.
Listen to a recording of the full teleconference and find a written summary of the discussion below.
Updates from Keith Lehman, Chief Provincial Veterinarian
Alberta Agriculture and Forestry
- PED was made a provincially reportable disease in Alberta following the first outbreaks in Canada in 2014. The disease is reportable in some provinces but not others.
- The first confirmed case was discovered on a farm northeast of Calgary, while the second and third confirmed cases were on farms near Lethbridge. All cases are 300- to 600-sow farrow-to-finish operations.
- The farm where the first case was detected has since emptied its inventory, while the farms where the second and third cases were detected are in the process of cleaning up and eliminating the disease while animals remain on-farm.
- Before any animals are moved, all animals are tested to ensure they are shedding at safe levels.
- When notified of an outbreak, the first response is biocontainment – keeping the virus from spreading to other farms by stopping pig movements and establishing restricted access zones (RAZ) around barns and controlled access zones (CAZ) for entire premises. If PED is suspected on a farm, even before tests can confirm it, biocontainment is recommended at the discretion of the producer and herd veterinarian.
- Following biocontainment, early steps in the investigation look at animal movements, based on manifests entered in the Alberta Swine Traceability Program, assisting producers and veterinarians to determine where the virus may have originated or where it could be going.
- All producers within a 50-kilometre radius of an affected premise are notified as soon as possible. Abattoirs, assembly yards and truck washes are notified if they are deemed a high risk.
- The PED Incident Command Centre is a military concept adapted to disease response. It is jointly run by Alberta Pork and Alberta Agriculture and Forestry. The command centre’s activities include daily phone calls with producers, processors, vets and other stakeholders in addition to the hands-on investigation.
- Counterparts in other provinces, especially Manitoba, have been instrumental in guiding Alberta’s response. Differences exist between Alberta and other known provinces where PED has been found, such as proximity of farms, and disease status of assembly yards. Alberta farms are farther apart, and assembly yards routinely test negative for diseases.
- In many cases, it is impossible to determine the exact source of the virus. In some cases, the source can be narrowed down to a short list of sites, but this is not often easy or quick to do.
- Investigation response is a lot of work and requires gathering a lot of information. Finite resources mean that the investigation process and the timeliness of communications can be competing priorities.
- The key priority at the beginning of an outbreak is to stop disease transmission, followed by communication with other stakeholders and the public. This process can take several hours or more depending on when the outbreak is discovered.
- Clear, accurate communication is imperative to ensure rumours do not spread. We must collaborate on this matter to prevent miscommunication.
Updates from Julia Keenliside, Veterinary Epidemiologist
Alberta Agriculture and Forestry
- Feed trucks and feed ingredients were considered possible sources of PED after other speculated sources were ruled out. Poor sanitation of people and equipment (especially clothing and vehicles) on-farm and a lack of proper RAZ and CAZ protocols are also a concern. With the Alberta outbreaks, no transport links have been confirmed so far for transmission of the virus.
- The first confirmed case was discovered in sows and several suckling pigs showing mild symptoms. This occurred on a Friday, and the vet came out on Saturday. He recognized the symptoms as possibly being PED, so he immediately contacted the Chief Provincial Veterinarian’s office on the after-hours phone number. Biosecurity measures were taken swiftly, and the virus was confirmed on the Monday after the weekend, with producer and public communication on Tuesday.
- The second confirmed case was over 300 kilometres away from the first case. It started as unusual diarrhea in a single farrowing group with no mortality, so PED was not initially suspected.
- The false positive case presented itself in piglet diarrhea with no mortality. No symptoms have been observed on this farm since it was first detected in the virus protein, which was present in a sample. Even if the PED virus is not alive, the protein (dead) can be detected by tests, hence the false positive.
- The third confirmed case is within 30 kilometres of the second case, and the producers in both cases use the same truck washes and assembly yards. These sites were tested, and the results were negative. It has also been difficult to determine an exact time of contamination. In this case, two- to three-week-old suckling pigs had unusual diarrhea but no mortality. As time went on, the virus was found in younger pigs, which resulted in mortality.
- The virus does not always show obvious signs quickly, but once it does, it works fast. Catching it early is the best way to limit impacts on herd.
- Hog transport links to areas where PED is known to exist outside the province—such as Manitoba and the U.S.—were the first to be identified and investigated as possible sources of transmission in all cases, but no links were found.
- Many types of feed, such as corn and soy, come from areas where PED is known to exist. Feed ingredients such as lysine (from China) and porcine blood plasma (from Quebec) are also speculated but not confirmed. Results were inconclusive with blood plasma, so further tests were sent to labs outside of the province, where the results were also inconclusive. These results have been frustrating for investigators and stakeholders alike.
- Both Manitoba and Ontario have had PED cases in the same span of time as Alberta—since the start of this calendar year. No blood plasma was used in those operations.
- All affected farms had feed located near the doors of barns, which can be a problem, especially if the virus is arriving on a transport vehicle near where the feed is being stored. This suggests a gap in biosecurity.
- Used equipment from Manitoba was used on the first affected farm but not the second or third farms. This is also a possible source of transmission but unlikely in these cases.
- Between second and third cases, there is suspected to be a transport link that could have transmitted the virus, but this remains unconfirmed.
- Rinsing with water alone is not enough to disinfect trailers; all vehicles must be washed thoroughly with soap, rinsed, disinfected and dried if moving between high-risk areas.
- Positive environmental test results will be reported and communicated publicly, if necessary, but none have been found to date.
- Outdoor operations make the virus more difficult to manage, but temperature and moisture will affect the length of time the virus survives. If the virus is frozen, it can live for several weeks but will not replicate outside of a pig.
- A negative test result does not mean a site is free from PED. Sampling can go only so far, and it’s possible the virus can be living on a surface, undetected, at a site that has tested negative. Caution is always advised against a false sense of security on these matters.
Updates from Javier Bahamon, Quality Assurance and Production Manager
- Alberta Pork’s environmental surveillance program is based on a plan developed in 2014.
- The program tracks the status of all coronaviruses in all high-traffic areas in Alberta.
- Over 20,000 samples have been collected since the beginning of the program. Of those samples, 73 per cent have come from processing facilities, 14 per cent from assembly yards and 13 per cent from truck wash bays.
- Over 3,000 samples were collected between January and March 2019 to be tested for PED. The number of weekly samples taken has more than doubled since the start of the outbreaks.