Open AccessAgreement Among 4 Sampling Methods to Identify Respiratory Pathogens in Dairy Calves with Acute Bovine Respiratory Disease
Author(s) -
Doyle D.,
Credille B.,
Lehenbauer T.W.,
Berghaus R.,
Aly S.S.,
Champagne J.,
Blanchard P.,
Crossley B.,
Berghaus L.,
Cochran S.,
Woolums A.
Publication year - 2017
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.14683
Subject(s) - bovine respiratory disease , mcnemar's test , medicine , pasteurella multocida , bronchoalveolar lavage , virology , pathogen , veterinary medicine , microbiology and biotechnology , biology , immunology , bacteria , lung , statistics , mathematics , genetics
Background Four sampling techniques commonly are used for antemortem identification of pathogens from cattle with bovine respiratory disease ( BRD ): the nasal swab ( NS ), guarded nasopharyngeal swab ( NPS ), bronchoalveolar lavage ( BAL ), and transtracheal wash ( TTW ). Agreement among these methods has not been well characterized. Objective To evaluate agreement among TTW and NS , NPS , or BAL for identification of viral and bacterial pathogens in dairy calves with BRD . Animals One hundred dairy calves with naturally acquired BRD. Methods Calves were sampled by all 4 methods. Viral agents were identified by real‐time RT ‐ PCR , bacteria were identified by aerobic culture, and Mycoplasma bovis ( M. bovis ) isolates were speciated by PCR . Agreement among TTW and NS , NPS , or BAL was evaluated by calculating the kappa statistic and percent positive agreement. McNemar's exact test was used to compare the proportions of positive results. Results Agreement among TTW and NS , TTW and NPS , and TTW and BAL , was very good for identification of P. multocida, M. haemolytica, and M. bovis . For bovine respiratory syncytial virus ( BRSV ), agreement with TTW was moderate for NS , good for NPS , and very good for BAL . For bovine coronavirus ( BCV ), agreement with TTW was moderate for NS and NPS , and good for BAL . McNemar's test was significant only for BCV , indicating that for this pathogen the proportion of positive results from NS and NPS could not be considered comparable to TTW . Conclusions and Clinical Importance This study provides guidance for veterinarians selecting diagnostic tests for antemortem identification of pathogens associated with BRD .