title: Economic costs associated with two testing strategies for screening feeder calves for persistent infection with bovine viral diarrhea virus.
abstract: OBJECTIVE
  To develop partial budgets of the economic costs of 2 test strategies for screening cattle for persistent infection with bovine viral diarrhea virus (BVDV).
  
  
  METHODS
  Partial budget analysis.
  
  
  METHODS
  938 calves arriving at 2 stocker operations.
  
  
  METHODS
  Calves were tested to determine prevalence of persistent BVDV infection. Test strategies that were evaluated included a single-test strategy consisting of immunohistochemical staining of skin biopsy specimens from all animals and a 2-test strategy consisting of polymerase chain reaction (PCR) assaying of pooled blood samples followed by immunohistochemical staining of skin biopsy specimens from animals in pools for which assay results were positive. Break-even costs (i.e., cost of persistent BVDV infection per animal necessary to justify whole-herd diagnostic testing) associated with each test strategy were calculated as a function of disease prevalence and test cost.
  
  
  RESULTS
  Apparent prevalence of persistent BVDV infection was 0.32%. Sensitivity and specificity of the PCR assay for pooled samples were 100% and 89.7%, respectively. Regardless of the prevalence of persistent BVDV infection, the break-even cost for the 2-test strategy was lower than the break-even cost for the single-test strategy. However, the economic advantage was greatest when prevalence was low.
  
  
  CONCLUSIONS
  Results suggest that using a 2-test strategy to screen cattle for persistent BVDV infection, whereby the first test involves PCR assaying of pooled samples and the second involves immunohistochemical testing only of those animals represented in pooled samples with positive assay results, will reduce the cost of screening incoming feedlot cattle, compared with immunohistochemical testing of all animals.
authors.affiliation: Department of Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Larson
authors.forename: Robert B
authors.initials: RB
authors.lastname: Miller
authors.forename: Steve B
authors.initials: SB
authors.lastname: Kleiboeker
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Miller
authors.forename: Brad J
authors.initials: BJ
authors.lastname: White
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000175:diagnosis* / Q000453:epidemiology; D002417:Cattle; D003362:Cost-Benefit Analysis; D001908:Diarrhea Viruses, Bovine Viral / Q000302:isolation & purification*; D007150:Immunohistochemistry / Q000191:economics / Q000379:methods / Q000662:veterinary*; D008403:Mass Screening / Q000191:economics / Q000379:methods / Q000662:veterinary*; D015995:Prevalence; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000191:economics / Q000379:methods / Q000662:veterinary*; D012680:Sensitivity and Specificity