title: Diagnostic evaluation of assays for detection of antibodies against porcine epidemic diarrhea virus (PEDV) in pigs exposed to different PEDV strains.
abstract: Porcine epidemic diarrhea virus (PEDV) has caused economic losses in the Americas, Asia and Europe in recent years. Reliable serological assays are essential for epidemiological studies and vaccine evaluation. The objective of this study was to compare the ability of five enzyme-linked immunosorbent assays (ELISAs) to detect antibodies against different PEDV strains in pig serum. A total of 732 serum samples from North American or European pigs were tested. Samples included experimental samples from pigs infected with classical (G1a PEDV) or variant genogroup 1 PEDV (G1b PEDV), pandemic genogroup 2 PEDV (G2b PEDV) or non-infected controls. Field samples from herds with confirmed or unknown PEDV exposure were also used. Three indirect ELISAs based on G2b antigens (ELISAs 1, 2 and 3), a competitive ELISA based on the G2b antigen (ELISA 4) and a competitive ELISA based on the G1a antigen (ELISA 5) were compared. Overall, the tests had a moderate agreement (κ=0.61). G1a PEDV infected pigs were earliest detected by ELISA 3, G1b PEDV infected pigs were earliest detected by ELISAs 4 and 5 and the performance of all tests was similar for the G2b PEDV group. ELISA 1 showed the overall lowest detection on experimentally and field derived samples. Diagnostic sensitivity and specificity with a 95% probability interval were estimated to be 68.2% (62.1-74.4%) and 97.5% (95.2-99.0%) for ELISA 1, 73.7% (71.5-79.6%) and 98.4% (96.6-99.5%) for ELISA 2, 86.2% (81.1-90.6%) and 91.6% (87.7-94.8%) for ELISA 3, 78.3% (72.8-83.5%) and 99.7% (98.2-100%) for ELISA 4, and 93.5% (90.3-96.0%) and 91.2% (83.8-97.9%) for ELISA 5. Differences in detection among assays seem to be more related to intrinsic factors of an assay than to the PEDV antigen used.
authors.affiliation: The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom.
authors.forename: Priscilla F
authors.initials: PF
authors.lastname: Gerber
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini", Brescia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Lelli
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: DTU National Veterinary Institute, Kalvehave, Denmark.
authors.forename: Bertel
authors.initials: B
authors.lastname: Strandbygaard
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini", Brescia, Italy.
authors.forename: Ana
authors.initials: A
authors.lastname: Moreno
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini", Brescia, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lavazza
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini", Brescia, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Perulli
authors.affiliation: DTU National Veterinary Institute, Kalvehave, Denmark.
authors.forename: Anette
authors.initials: A
authors.lastname: Bøtner
authors.affiliation: Innovative Diagnostics IDvet, Grabels, France.
authors.forename: Loic
authors.initials: L
authors.lastname: Comtet
authors.affiliation: Innovative Diagnostics IDvet, Grabels, France.
authors.forename: Mickael
authors.initials: M
authors.lastname: Roche
authors.affiliation: Innovative Diagnostics IDvet, Grabels, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pourquier
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.affiliation: The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom; Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA. Electronic address: Tanja.Opriessnig@roslin.ed.ac.uk.
authors.forename: Tanja
authors.initials: T
authors.lastname: Opriessnig
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D003333:Coronaviridae Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D003718:Denmark; D019937:Diagnostic Techniques and Procedures / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D007558:Italy; D053485:Porcine epidemic diarrhea virus / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000821:virology; D014481:United States
chemical_list: D000914:Antibodies, Viral
keywords: Diagnosis; ELISA; Global comparison; Porcine epidemic diarrhea virus