title: Modeling the transboundary risk of feed ingredients contaminated with porcine epidemic diarrhea virus.
abstract: BACKGROUND
  This study describes a model developed to evaluate the transboundary risk of PEDV-contaminated swine feed ingredients and the effect of two mitigation strategies during a simulated transport event from China to the US.
  
  
  RESULTS
  Ingredients imported to the USA from China, including organic & conventional soybeans and meal, lysine hydrochloride, D-L methionine, tryptophan, Vitamins A, D & E, choline, carriers (rice hulls, corn cobs) and feed grade tetracycline, were inoculated with PEDV. Control ingredients, and treatments (ingredients plus a liquid antimicrobial (SalCURB, Kemin Industries (LA) or a 2% custom medium chain fatty acid blend (MCFA)) were tested. The model ran for 37 days, simulating transport of cargo from Beijing, China to Des Moines, IA, US from December 23, 2012 to January 28, 2013. To mimic conditions on land and sea, historical temperature and percent relative humidity (% RH) data were programmed into an environmental chamber which stored all containers. To evaluate PEDV viability over time, ingredients were organized into 1 of 4 batches of samples, each batch representing a specific segment of transport. Batch 1 (segment 1) simulated transport of contaminated ingredients from manufacturing plants in Beijing (day 1 post-contamination (PC)). Batch 2 (segments 1 and 2) simulated manufacturing and delivery to Shanghai, including time in Anquing terminal awaiting shipment (days 1-8 PC). Batch 3 (segments 1, 2 and 3) represented time in China, the crossing of the Pacific and entry to the US at the San Francisco, CA terminal (day 1-27 PC). Batch 4 (segments 1-4) represented the previous events, including transport to Des Moines, IA (days 1-37 PC). Across control (non-treated) ingredients, viable PEDV was detected in soybean meal (organic and conventional), Vitamin D, lysine hydrochloride and choline chloride. In contrast, viable PEDV was not detected in any samples treated with LA or MCFA.
  
  
  CONCLUSIONS
  These results demonstrate the ability of PEDV to survive in a subset of feed ingredients using a model simulating shipment from China to the US. This is proof of concept suggesting that contaminated feed ingredients could serve as transboundary risk factors for PEDV, along with the identification of effective mitigation options.
authors.affiliation: Pipestone Applied Research, Pipestone Veterinary Services, 1300 Box, 188 Hwy 75 S, Pipestone, MN, 56164, USA. sdee@pipevet.com.
authors.forename: Scott
authors.initials: S
authors.lastname: Dee
authors.affiliation: Pipestone Applied Research, Pipestone Veterinary Services, 1300 Box, 188 Hwy 75 S, Pipestone, MN, 56164, USA.
authors.forename: Casey
authors.initials: C
authors.lastname: Neill
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Singrey
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA.
authors.forename: Travis
authors.initials: T
authors.lastname: Clement
authors.affiliation: Department of Grain Science, Kansas State University, Manhattan, KS, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Cochrane
authors.affiliation: Department of Grain Science, Kansas State University, Manhattan, KS, USA.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Jones
authors.affiliation: Center for Animal Health and Food Safety, University of Minnesota, St. Paul, MN, USA.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Patterson
authors.affiliation: Pipestone Applied Research, Pipestone Veterinary Services, 1300 Box, 188 Hwy 75 S, Pipestone, MN, 56164, USA.
authors.forename: Gordon
authors.initials: G
authors.lastname: Spronk
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA.
authors.forename: Jane
authors.initials: J
authors.lastname: Christopher-Hennings
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Nelson
mesh_terms: D000821:Animal Feed / Q000821:virology*; D000818:Animals; D001681:Biological Assay; D002681:China; D018352:Coronavirus Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000592:standards*; D006813:Humidity; D008962:Models, Theoretical; D053485:Porcine epidemic diarrhea virus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D013552:Swine; D013553:Swine Diseases / Q000635:transmission / Q000821:virology; D013696:Temperature; D014186:Transportation
keywords: Antimicrobial; Choline; Diarrhea; Epidemic; Ingredient; Lysine; Porcine; Soybean meal; Transboundary; Virus