Porcine epidemic diarrhea virus RNA present in commercial spray-dried porcine plasma is not infectious to naïve pigs

PLoS One. 2014 Aug 12;9(8):e104766. doi: 10.1371/journal.pone.0104766. eCollection 2014.

Abstract

Porcine epidemic diarrhea virus emerged in North America in April 2013 and has since been identified in 30 U.S. States, Canada and Mexico. The rapid spread of PEDV has raised concerns about the role of feed and particularly pork-by-product components such as spray-dried porcine plasma (SDPP) in PEDV transmission. The aim of this study was to determine the infectivity of PEDV RNA present in commercial SDPP. Specifically, 40 3-week-old PEDV naïve pigs were randomly assigned to one of five treatment groups. At day post inoculation (dpi) 0, NEG-CONTROL pigs were sham-inoculated, PEDV-CONTROL pigs received cell culture propagated PEDV, and SDPP-CONTROL pigs were switched to a diet with 5% SDPP containing 5.1±0.1 log10 PEDV RNA copies/g. To evaluate a potential positive effect of anti-PEDV antibodies in SDPP on PEDV challenge, four days prior to PEDV challenge the pigs in the SDPP-PEDV group were switched to and remained on a 5% SDPP diet through dpi 28. Another group, EGG-PEDV, was orally administered a commercial egg-derived liquid PEDV globulin product from dpi -4 through 6. All PEDV-CONTROL pigs began shedding PEDV in feces by dpi 3 and seroconverted between dpi 7 and 14, whereas pigs in NEG-CONTROL and SDPP-CONTROL groups remained PEDV RNA negative and did not seroconvert to PEDV for the study duration. This indicates no evidence of infectivity of the PEDV RNA in the SDPP lot utilized. Furthermore, under the study conditions SDPP or egg-derived liquid PEDV globulin addition did not significantly alter PEDV-shedding or overall disease course after experimental challenge.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed / virology
  • Animals
  • Antibodies, Viral / immunology
  • Communicable Diseases / blood
  • Communicable Diseases / transmission*
  • Communicable Diseases / virology
  • Coronavirus Infections / blood
  • Coronavirus Infections / transmission*
  • Coronavirus Infections / virology
  • Diet / veterinary
  • Feces / virology
  • Porcine epidemic diarrhea virus / genetics
  • Porcine epidemic diarrhea virus / pathogenicity*
  • RNA, Viral / blood
  • Random Allocation
  • Swine / blood*
  • Swine Diseases / blood
  • Swine Diseases / transmission*
  • Swine Diseases / virology
  • United States
  • Viremia / blood

Substances

  • Antibodies, Viral
  • RNA, Viral

Grants and funding

Funding for this study was provided in part by APC, Inc., Ankeny, Iowa, United States of America and EPFX/EGCO Protein, Provanco Feeds, Le Center, Minnesota, United States of America. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.