Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama)

D. F. Twomey, T. R. Crawshaw, J. E. Anscombe, J. E.F. Barnett, L. Farrant, L. J. Evans, W. S. McElligott, Robert Higgins, G. S. Dean, H. M. Vordermeier, R. De La Rua-Domenech

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

An outbreak of tuberculosis (TB) caused by Mycobacterium bovis in a llama herd is described. Over a 25-month period, a total of 70 llamas were selected for postmortem examination using four distinct criteria: clinical suspicion of disease (15 animals), positive tuberculin skin test result (three animals), antibody positive using a novel serological test (Rapid Test, 54 animals) and elective cull (five animals). Some animals qualified on more than one criterion. Gross lesions of TB were detected in 15 animals, with lung and lymph node lesions consistently observed. Samples were collected from 14 of 15 animals with visible lesions as well as those with no visible lesions, for histopathology and mycobacterial culture. All 14 llamas with visible lesions had caseonecrotic granulomatous lesions associated with acid-fast bacteria and variable mineralisation, and M bovis was isolated from 13. There were no histopathological lesions of TB in llamas with no grossly visible lesions, and M bovis was not isolated from any of these. The predictive value of suspicious gross lesions at postmortem examination was therefore high in the herd. Molecular typing results indicated that the outbreak was caused by a single strain likely to have originated from a local reservoir, probably cattle or wildlife. Antemortem indicators of infection assisted control of the outbreak, but no single test accurately identified all TB cases. Visible lesions were detected in nine of 15 llamas with clinical suspicion of disease, in two of three that had positive tuberculin skin test results and in 10 of 54 that were antibody positive; there was none (zero out of five) in llamas that were electively culled.

Original languageEnglish (US)
Pages (from-to)475-480
Number of pages6
JournalVeterinary Record
Volume167
Issue number13
DOIs
StatePublished - Sep 25 2010
Externally publishedYes

Fingerprint

New World Camelids
llamas
tuberculosis
lesions (animal)
Disease Outbreaks
Tuberculosis
Tuberculin Test
testing
Skin Tests
animals
Autopsy
tuberculin
skin tests
Molecular Typing
Animal Diseases
Antibodies
Serologic Tests
Infection Control
Mycobacterium bovis
necropsy

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Twomey, D. F., Crawshaw, T. R., Anscombe, J. E., Barnett, J. E. F., Farrant, L., Evans, L. J., ... De La Rua-Domenech, R. (2010). Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama). Veterinary Record, 167(13), 475-480. https://doi.org/10.1136/vr.c4192

Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama). / Twomey, D. F.; Crawshaw, T. R.; Anscombe, J. E.; Barnett, J. E.F.; Farrant, L.; Evans, L. J.; McElligott, W. S.; Higgins, Robert; Dean, G. S.; Vordermeier, H. M.; De La Rua-Domenech, R.

In: Veterinary Record, Vol. 167, No. 13, 25.09.2010, p. 475-480.

Research output: Contribution to journalArticle

Twomey, DF, Crawshaw, TR, Anscombe, JE, Barnett, JEF, Farrant, L, Evans, LJ, McElligott, WS, Higgins, R, Dean, GS, Vordermeier, HM & De La Rua-Domenech, R 2010, 'Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama)', Veterinary Record, vol. 167, no. 13, pp. 475-480. https://doi.org/10.1136/vr.c4192
Twomey DF, Crawshaw TR, Anscombe JE, Barnett JEF, Farrant L, Evans LJ et al. Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama). Veterinary Record. 2010 Sep 25;167(13):475-480. https://doi.org/10.1136/vr.c4192
Twomey, D. F. ; Crawshaw, T. R. ; Anscombe, J. E. ; Barnett, J. E.F. ; Farrant, L. ; Evans, L. J. ; McElligott, W. S. ; Higgins, Robert ; Dean, G. S. ; Vordermeier, H. M. ; De La Rua-Domenech, R. / Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama). In: Veterinary Record. 2010 ; Vol. 167, No. 13. pp. 475-480.
@article{5cbd53adccdd4a33a7f49ba14cb36827,
title = "Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama)",
abstract = "An outbreak of tuberculosis (TB) caused by Mycobacterium bovis in a llama herd is described. Over a 25-month period, a total of 70 llamas were selected for postmortem examination using four distinct criteria: clinical suspicion of disease (15 animals), positive tuberculin skin test result (three animals), antibody positive using a novel serological test (Rapid Test, 54 animals) and elective cull (five animals). Some animals qualified on more than one criterion. Gross lesions of TB were detected in 15 animals, with lung and lymph node lesions consistently observed. Samples were collected from 14 of 15 animals with visible lesions as well as those with no visible lesions, for histopathology and mycobacterial culture. All 14 llamas with visible lesions had caseonecrotic granulomatous lesions associated with acid-fast bacteria and variable mineralisation, and M bovis was isolated from 13. There were no histopathological lesions of TB in llamas with no grossly visible lesions, and M bovis was not isolated from any of these. The predictive value of suspicious gross lesions at postmortem examination was therefore high in the herd. Molecular typing results indicated that the outbreak was caused by a single strain likely to have originated from a local reservoir, probably cattle or wildlife. Antemortem indicators of infection assisted control of the outbreak, but no single test accurately identified all TB cases. Visible lesions were detected in nine of 15 llamas with clinical suspicion of disease, in two of three that had positive tuberculin skin test results and in 10 of 54 that were antibody positive; there was none (zero out of five) in llamas that were electively culled.",
author = "Twomey, {D. F.} and Crawshaw, {T. R.} and Anscombe, {J. E.} and Barnett, {J. E.F.} and L. Farrant and Evans, {L. J.} and McElligott, {W. S.} and Robert Higgins and Dean, {G. S.} and Vordermeier, {H. M.} and {De La Rua-Domenech}, R.",
year = "2010",
month = "9",
day = "25",
doi = "10.1136/vr.c4192",
language = "English (US)",
volume = "167",
pages = "475--480",
journal = "Veterinary Record",
issn = "0042-4900",
publisher = "British Veterinary Association",
number = "13",

}

TY - JOUR

T1 - Assessment of antemortem tests used in the control of an outbreak of tuberculosis in llamas (Lama glama)

AU - Twomey, D. F.

AU - Crawshaw, T. R.

AU - Anscombe, J. E.

AU - Barnett, J. E.F.

AU - Farrant, L.

AU - Evans, L. J.

AU - McElligott, W. S.

AU - Higgins, Robert

AU - Dean, G. S.

AU - Vordermeier, H. M.

AU - De La Rua-Domenech, R.

PY - 2010/9/25

Y1 - 2010/9/25

N2 - An outbreak of tuberculosis (TB) caused by Mycobacterium bovis in a llama herd is described. Over a 25-month period, a total of 70 llamas were selected for postmortem examination using four distinct criteria: clinical suspicion of disease (15 animals), positive tuberculin skin test result (three animals), antibody positive using a novel serological test (Rapid Test, 54 animals) and elective cull (five animals). Some animals qualified on more than one criterion. Gross lesions of TB were detected in 15 animals, with lung and lymph node lesions consistently observed. Samples were collected from 14 of 15 animals with visible lesions as well as those with no visible lesions, for histopathology and mycobacterial culture. All 14 llamas with visible lesions had caseonecrotic granulomatous lesions associated with acid-fast bacteria and variable mineralisation, and M bovis was isolated from 13. There were no histopathological lesions of TB in llamas with no grossly visible lesions, and M bovis was not isolated from any of these. The predictive value of suspicious gross lesions at postmortem examination was therefore high in the herd. Molecular typing results indicated that the outbreak was caused by a single strain likely to have originated from a local reservoir, probably cattle or wildlife. Antemortem indicators of infection assisted control of the outbreak, but no single test accurately identified all TB cases. Visible lesions were detected in nine of 15 llamas with clinical suspicion of disease, in two of three that had positive tuberculin skin test results and in 10 of 54 that were antibody positive; there was none (zero out of five) in llamas that were electively culled.

AB - An outbreak of tuberculosis (TB) caused by Mycobacterium bovis in a llama herd is described. Over a 25-month period, a total of 70 llamas were selected for postmortem examination using four distinct criteria: clinical suspicion of disease (15 animals), positive tuberculin skin test result (three animals), antibody positive using a novel serological test (Rapid Test, 54 animals) and elective cull (five animals). Some animals qualified on more than one criterion. Gross lesions of TB were detected in 15 animals, with lung and lymph node lesions consistently observed. Samples were collected from 14 of 15 animals with visible lesions as well as those with no visible lesions, for histopathology and mycobacterial culture. All 14 llamas with visible lesions had caseonecrotic granulomatous lesions associated with acid-fast bacteria and variable mineralisation, and M bovis was isolated from 13. There were no histopathological lesions of TB in llamas with no grossly visible lesions, and M bovis was not isolated from any of these. The predictive value of suspicious gross lesions at postmortem examination was therefore high in the herd. Molecular typing results indicated that the outbreak was caused by a single strain likely to have originated from a local reservoir, probably cattle or wildlife. Antemortem indicators of infection assisted control of the outbreak, but no single test accurately identified all TB cases. Visible lesions were detected in nine of 15 llamas with clinical suspicion of disease, in two of three that had positive tuberculin skin test results and in 10 of 54 that were antibody positive; there was none (zero out of five) in llamas that were electively culled.

UR - http://www.scopus.com/inward/record.url?scp=79952058163&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79952058163&partnerID=8YFLogxK

U2 - 10.1136/vr.c4192

DO - 10.1136/vr.c4192

M3 - Article

C2 - 20871080

AN - SCOPUS:79952058163

VL - 167

SP - 475

EP - 480

JO - Veterinary Record

JF - Veterinary Record

SN - 0042-4900

IS - 13

ER -