title: Comparison of different commercial ELISAs for detection of antibodies against porcine respiratory and reproductive syndrome virus in serum.
abstract: BACKGROUND
  In recent years, several new ELISAs for the detection of antibodies against the porcine reproductive and respiratory disease virus (PRRSV) in pig serum have been developed. To interpret the results, specificity and sensitivity data as well as agreement to a reference ELISA must be available. In this study, three commercial ELISAs (INgezim PRRS 2.0 - ELISA II, Priocheck® PRRSV Ab porcine - ELISA III and CIVTEST suis PRRS E/S PLUS - ELISA IV, detecting PRRSV type 1 antibodies) were compared to a standard ELISA (IDEXX PRRS X3 Ab Test - ELISA I). The serum of three pigs vaccinated with an attenuated PRRSV live vaccine (genotype 2) was tested prior to and several times after the vaccination. Furthermore, serum samples of 245 pigs of PRRSV positive herds, 309 pigs of monitored PRRSV negative herds, 256 fatteners of assumed PRRSV negative herds with unknown herd history and 92 wild boars were tested with all four ELISAs.
  
  
  RESULTS
  ELISAs II and III were able to detect seroconversion of vaccinated pigs with a similar reliability. According to kappa coefficient, the results showed an almost perfect agreement between ELISA I as reference and ELISA II and III (kappa > 0.8), and substantial agreement between ELISA I and ELISA IV (kappa = 0.71). Sensitivity of ELISA II, III and IV was 96.0%, 100% and 91.5%, respectively. The specificity of the ELISAs determined in samples of monitored PRRSV negative herds was 99.0%, 95.1% and 96.4%, respectively. In assumed negative farms that were not continually monitored, more positive samples were found with ELISA II to IV. The reference ELISA I had a specificity of 100% in this study.
  
  
  CONCLUSIONS
  All tested ELISAs were able to detect a PRRSV positive herd. The specificity and sensitivity of the tested commercial ELISAs, however, differed. ELISA II had the highest specificity and ELISA III had the highest sensitivity in comparison to the reference ELISA. ELISA IV had a lower sensitivity and specificity than the other ELISAs.
authors.affiliation: Large Animal Clinic for Internal Medicine, University of Leipzig, An den Tierkliniken 11, 04103, Leipzig, Germany. tasat@vetmed.uni-leipzig.de.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Sattler
authors.affiliation: Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria. eveline.wodak@ages.at.
authors.forename: Eveline
authors.initials: E
authors.lastname: Wodak
authors.affiliation: Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria. sandra.revilla-fernandez@ages.at.
authors.forename: Sandra
authors.initials: S
authors.lastname: Revilla-Fernández
authors.affiliation: Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria. friedrich.schmoll@ages.at.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Schmoll
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D005260:Female; D008297:Male; D019318:Porcine Reproductive and Respiratory Syndrome / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D012367:RNA, Viral / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine / Q000097:blood / Q000276:immunology / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral