title: Diagnostic efficacy of a reverse transcriptase-polymerase chain reaction assay to screen cattle for persistent bovine viral diarrhea virus infection.
abstract: OBJECTIVE
  To evaluate diagnostic efficacy of a reverse transcriptase-PCR assay performed on pooled supernatant from fresh tissue samples to screen cattle for persistent infection with bovine viral diarrhea virus (BVDV).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  174 pooled supernatant samples representing 12,528 animals between 1 and 12 months old.
  
  
  METHODS
  The supernatant was collected from fresh tissue samples suspended in phosphate-buffered saline solution that had been submitted for testing for BVDV infection. Supernatant samples were pooled, with pool size limited to < or = 100 samples, and assayed with a reverse transcriptase-PCR assay for BVDV. Results of the PCR assay were compared with results of an antigen-capture ELISA performed on individual tissue samples.
  
  
  RESULTS
  Results of the PCR assay were positive for 27 of the 174 pooled samples (mean pool size, 72 samples). For 23 of these 27 pooled samples, results of the ELISA were positive for 1 or more of the individual tissue samples represented in the pooled sample, whereas for 4 of these pooled samples, results of the ELISA were negative for all individual tissue samples represented in the pooled sample. Results of the ELISA were negative for all individual tissue samples represented in the 147 pooled samples with negative PCR assay results.
  
  
  CONCLUSIONS
  Results suggested that the reverse transcriptase-PCR assay can be used to screen cattle for persistent BVDV infection, with calculated sensitivity of 100% (95% confidence interval, 85.2% to 100%) and calculated specificity of 97.5% (95% confidence interval, 93.4% to 99.3%).
authors.affiliation: Colorado State University Veterinary Diagnostic Laboratory, Rocky Ford Branch, 27847 Rd 21, Rocky Ford, CO 81067, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D002417:Cattle; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D001908:Diarrhea Viruses, Bovine Viral / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D008403:Mass Screening / Q000662:veterinary*; D015995:Prevalence; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000592:standards / Q000662:veterinary*; D012680:Sensitivity and Specificity