title: An evaluation of contaminated complete feed as a vehicle for porcine epidemic diarrhea virus infection of naïve pigs following consumption via natural feeding behavior: proof of concept.
abstract: BACKGROUND
  Since its initial detection in May 2013, porcine epidemic diarrhea virus (PEDV) has spread rapidly throughout the US swine industry. Initially, contaminated feed was proposed as a risk factor for PEDV; however, data were not available to support this theory. Here we provide proof of concept of this risk by describing a novel means for recovering PEDV-contaminated complete feed material from commercial swine sites and conducting an in vivo experiment to prove its infectivity.
  
  
  RESULTS
  For on-farm detection of PEDV RNA in feed, paint rollers were used to collect material from at-risk feed bins from 3 clinically affected breeding herds. This material was tested by PCR and determined to be positive for PEDV-RNA (Ct = 19.50-22.20 range). To test infectivity, this material was pooled (Ct = 20.65) and a Treatment group of 3-week old PEDV-naïve piglets were allowed to consume it via natural feeding behavior. For the purpose of a Positive control, piglets were allowed to ingest feed spiked with stock PEDV (Ct = 18.23) while the negative control group received PEDV-free feed. Clinical signs of PEDV infection (vomiting and diarrhea) and viral shedding were observed in both the Positive control and Treatment group' post-consumption with virus and microscopic lesions detected in intestinal samples No evidence of infection was observed in the Negative controls.
  
  
  CONCLUSIONS
  These data provide proof of concept that contaminated complete feed can serve as a vehicle for PEDV infection of naïve pigs using natural feeding behavior.
authors.affiliation: Pipestone Applied Research, Pipestone Veterinary Services, Pipestone, MN, USA. sdee@pipevet.com.
authors.forename: Scott
authors.initials: S
authors.lastname: Dee
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA. travis.clement@sdstate.edu.
authors.forename: Travis
authors.initials: T
authors.lastname: Clement
authors.affiliation: Pipestone Applied Research, Pipestone Veterinary Services, Pipestone, MN, USA. aschelkopf@pipevet.com.
authors.forename: Adam
authors.initials: A
authors.lastname: Schelkopf
authors.affiliation: Pipestone Applied Research, Pipestone Veterinary Services, Pipestone, MN, USA. jnerem@pipevet.com.
authors.forename: Joel
authors.initials: J
authors.lastname: Nerem
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA. david.knudsen@sdstate.edu.
authors.forename: David
authors.initials: D
authors.lastname: Knudsen
authors.affiliation: Animal Disease Research and Diagnostic Laboratory, South Dakota State University, Brookings, SD, USA. jane.hennings@sdstate.edu.
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. eric.nelson@sdstate.edu.
authors.forename: Eric
authors.initials: E
authors.lastname: Nelson
mesh_terms: D000821:Animal Feed / Q000032:analysis / Q000821:virology*; D000818:Animals; D000831:Animals, Newborn / Q000821:virology; D018352:Coronavirus Infections / Q000209:etiology / Q000662:veterinary* / Q000821:virology; D003967:Diarrhea / Q000209:etiology / Q000662:veterinary* / Q000821:virology; D005506:Food Contamination; D053485:Porcine epidemic diarrhea virus; D012367:RNA, Viral / Q000032:analysis; D013552:Swine; D013553:Swine Diseases / Q000209:etiology* / Q000821:virology
chemical_list: D012367:RNA, Viral
references.citation: J Clin Microbiol. 2014 Jan;52(1):234-43
references.pmid: 24197882
references.citation: Vet Microbiol. 2009 Apr 14;136(1-2):1-7
references.pmid: 19046835
references.citation: Emerg Infect Dis. 2014 May;20(5):872-4
references.pmid: 24750785
references.citation: Vet Rec. 1994 Dec 17;135(25):594-7
references.pmid: 7900243
references.citation: Virus Res. 2010 Dec;154(1-2):177-84
references.pmid: 20667494