title: Evaluation of porcine epidemic diarrhea virus transmission and the immune response in growing pigs.
abstract: Clinical disease associated with porcine epidemic diarrhea virus (PEDV) infection in naïve pigs is well chronicled; however, information on endemic PEDV infection is limited. To characterize chronic PEDV infection, the duration of infectious virus shedding and development of protective immunity was determined. On Day 0 (D0), a growing pig was challenged with PEDV and 13 contacts were commingled. On D7, 9 contact pigs (principal virus group (PG)), were selected, moved to a separate room and commingled with one sentinel pig (S1). This process was repeated weekly with S2, S3 and S4. The PG was PEDV-positive by PCR from D3-11, with some pigs intermittently positive to D42. Pigs S1 and S2 were PEDV-positive within 24 hours of commingling. Antibodies were detected in all PG by D21 and by 7 days post-contact in S1 and S2. Pigs S3 and S4 were PCR and antibody negative following commingling. To evaluate protective immunity, 5 naïve pigs (N) and the PG were challenged (N/C, PG/C) with homologous virus on D49. All N/C pigs were PEDV PCR-positive by D52 with detection out to D62 in 3/5 N/C pigs. All PG/C pigs were PEDV PCR-negative post-challenge. By D63, all N/C seroconverted. Although PEDV RNA was demonstrated in pigs after primary infection until D42, infectious PEDV capable of horizontal transmission to naïve pigs was only shed 14-16 days after infection to age-matched pigs. Homologous re-challenge 49 days post initial PEDV exposure did not result in re-infection of the pigs. This demonstrates potential for an effective PEDV vaccine.
authors.affiliation: National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA. Kimberly.crawford@ars.usda.gov.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Crawford
authors.affiliation: National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA. Kelly.lager@ars.usda.gov.
authors.forename: Kelly
authors.initials: K
authors.lastname: Lager
authors.affiliation: National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA. Laura.miller@ars.usda.gov.
authors.forename: Laura
authors.initials: L
authors.lastname: Miller
authors.affiliation: Veterinary Diagnostic and Production Animal Medicine, Iowa State University College of Veterinary Medicine, Ames, IA, USA. tanjaopr@iastate.edu.|The Roslin Institute, University of Edinburgh, Midlothian, UK. tanjaopr@iastate.edu.
authors.forename: Tanja
authors.initials: T
authors.lastname: Opriessnig
authors.affiliation: Veterinary Diagnostic and Production Animal Medicine, Iowa State University College of Veterinary Medicine, Ames, IA, USA. pgerber@iastate.edu.|The Roslin Institute, University of Edinburgh, Midlothian, UK. pgerber@iastate.edu.
authors.forename: Priscilla
authors.initials: P
authors.lastname: Gerber
authors.affiliation: Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA. dhesse@vet.k-state.edu.
authors.forename: Richard
authors.initials: R
authors.lastname: Hesse
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D018352:Coronavirus Infections / Q000276:immunology / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D007113:Immunity, Innate; D053485:Porcine epidemic diarrhea virus / Q000502:physiology*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000635:transmission* / Q000821:virology; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral