title: Comparison of ear notch immunohistochemistry, ear notch antigen-capture ELISA, and buffy coat virus isolation for detection of calves persistently infected with bovine viral diarrhea virus.
abstract: Two techniques performed on skin biopsy samples (ear notches), immunohistochemistry (IHC) and antigen-capture ELISA (AgELISA), were compared for detection of bovine viral diarrhea virus (BVDV) persistent infection (PI) in 559 Angus calves between the ages of 1 and 5 months. The calves also were tested for BVDV infection using virus isolation (VI) and reverse transcription (RT)-PCR on buffy coat samples and for antibodies to BVDV types la and 2 by serum neutralization (SN). Sixty-seven of 559 (12.0%) calves tested positive at initial screening by IHC, AgELISA, or VI, and all 67 were kept for a minimum of 3 months and retested monthly by IHC, AgELISA, VI, RT-PCR, and SN. Of the calves positive at initial screening, 59/67 (88.1%) were determined PI and 8/67 (11.9%) were determined acutely infected. Both IHC and AgELISA detected 100% of PI calves; however, IHC and AgELISA also detected 6 and 8 acutely infected calves, respectively, at initial screening. Furthermore, IHC and AgELISA continued to detect 3 and 4 acutely infected calves, respectively, 3 months after initial screening. Three acutely infected calves had IHC staining indistinguishable from PI calves at initial screening. Both IHC and AgELISA are accurate at detecting BVDV-infected calves, but veterinarians and producers should be advised that both tests detect some calves acutely infected with BVDV in addition to PI animals. Repeat testing using VI or RT-PCR on buffy coat samples should be performed at 30 days after initial screening to conclusively discriminate between acute and PI.
authors.affiliation: Wyoming State Veterinary Laboratory, Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82070, USA.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Cornish
authors.forename: Alberto L
authors.initials: AL
authors.lastname: van Olphen
authors.forename: Jacqueline L
authors.initials: JL
authors.lastname: Cavender
authors.forename: Joan M
authors.initials: JM
authors.lastname: Edwards
authors.forename: Paula T
authors.initials: PT
authors.lastname: Jaeger
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Vieyra
authors.forename: Lynn F
authors.initials: LF
authors.lastname: Woodard
authors.forename: Dan R
authors.initials: DR
authors.lastname: Miller
authors.forename: Donal
authors.initials: D
authors.lastname: O'Toole
mesh_terms: D000208:Acute Disease; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000175:diagnosis*; D002417:Cattle; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D007120:Immunochemistry / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012680:Sensitivity and Specificity
chemical_list: D000956:Antigens, Viral