title: Investigation into the role of potentially contaminated feed as a source of the first-detected outbreaks of porcine epidemic diarrhea in Canada.
abstract: In January 2014, approximately 9 months following the initial detection of porcine epidemic diarrhea (PED) in the USA, the first case of PED was confirmed in a swine herd in south-western Ontario. A follow-up epidemiological investigation carried out on the initial and 10 subsequent Ontario PED cases pointed to feed as a common risk factor. As a result, several lots of feed and spray-dried porcine plasma (SDPP) used as a feed supplement were tested for the presence of PEDV genome by real-time RT-PCR assay. Several of these tested positive, supporting the notion that contaminated feed may have been responsible for the introduction of PEDV into Canada. These findings led us to conduct a bioassay experiment in which three PEDV-positive SDPP samples (from a single lot) and two PEDV-positive feed samples supplemented with this SDPP were used to orally inoculate 3-week-old piglets. Although the feed-inoculated piglets did not show any significant excretion of PEDV, the SDPP-inoculated piglets shed PEDV at a relatively high level for ≥9 days. Despite the fact that the tested PEDV genome positive feed did not result in obvious piglet infection in our bioassay experiment, contaminated feed cannot be ruled out as a likely source of this introduction in the field where many other variables may play a contributing role.
authors.affiliation: Canadian Food Inspection Agency, National Centres for Animal Disease, National Centre for Foreign Animal Disease, Winnipeg, MB, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Pasick
authors.forename: Y
authors.initials: Y
authors.lastname: Berhane
authors.forename: D
authors.initials: D
authors.lastname: Ojkic
authors.forename: G
authors.initials: G
authors.lastname: Maxie
authors.forename: C
authors.initials: C
authors.lastname: Embury-Hyatt
authors.forename: K
authors.initials: K
authors.lastname: Swekla
authors.forename: K
authors.initials: K
authors.lastname: Handel
authors.forename: J
authors.initials: J
authors.lastname: Fairles
authors.forename: S
authors.initials: S
authors.lastname: Alexandersen
mesh_terms: D000821:Animal Feed / Q000821:virology*; D000818:Animals; D002170:Canada / Q000453:epidemiology; D018352:Coronavirus Infections / Q000662:veterinary* / Q000821:virology; D003967:Diarrhea / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D004196:Disease Outbreaks / Q000662:veterinary*; D005506:Food Contamination; D008969:Molecular Sequence Data; D053485:Porcine epidemic diarrhea virus; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000209:etiology*
keywords: porcine epidemic diarrhea; spray-dried porcine plasma; transmission
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