scholarly journals Test characteristics of the tuberculin skin test and post-mortem examination for bovine tuberculosis diagnosis in cattle in Northern Ireland estimated by Bayesian latent class analysis with adjustments for covariates

2019 ◽  
Vol 147 ◽  
Author(s):  
M. J. H. O'Hagan ◽  
H. Ni ◽  
F. D. Menzies ◽  
A. V. Pascual-Linaza ◽  
A. Georgaki ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Bovine Tuberculosis ◽  
Latent Class ◽  
Latent Class Model ◽  
Diagnostic Tools ◽  
Post Mortem ◽  
Standard Interpretation ◽  
Posterior Median ◽  
Post Mortem Examination ◽  
Test Characteristics

AbstractThe single intradermal comparative cervical tuberculin (SICCT) test and post-mortem examination are the main diagnostic tools for bovine tuberculosis (bTB) in cattle in the British Isles. Latent class modelling is often used to estimate the bTB test characteristics due to the absence of a gold standard. However, the reported sensitivity of especially the SICCT test has shown a lot of variation. We applied both the Hui–Walter latent class model under the Bayesian framework and the Bayesian model specified at the animal level, including various risk factors as predictors, to estimate the SICCT test and post-mortem test characteristics. Data were collected from all cattle slaughtered in abattoirs in Northern Ireland in 2015. Both models showed comparable posterior median estimation for the sensitivity of the SICCT test (88.61% and 90.56%, respectively) using standard interpretation and for post-mortem examination (53.65% and 53.79%, respectively). Both models showed almost identical posterior median estimates for the specificity (99.99% vs. 99.80% for SICCT test at standard interpretation and 99.66% vs. 99.86% for post-mortem examination). The animal-level model showed slightly narrower posterior 95% credible intervals. Notably, this study was carried out in slaughtered cattle which may not be representative for the general cattle population.

scholarly journals Improvement of bovine tuberculosis diagnosis

2021 ◽  
pp. 261-265
Author(s):  
M. O. Baratov
Keyword(s):  
Red Blood Cells ◽  
Mycobacterium Bovis ◽  
Blood Cells ◽  
Bovine Tuberculosis ◽  
Intradermal Test ◽  
Mycobacterium Fortuitum ◽  
Post Mortem ◽  
Post Mortem Examination ◽  
Antibody Titers ◽  
Specific Reactions

Detection of animals with non-specific reactions to tuberculin is one of the major problems in bovine tuberculosis (TB) diagnosis. There is a need to find and improve methods for detection of the sensitization causes. This paper presents the results of comparative studies of different ways to stabilize red blood cells in order to obtain diagnosticums for indirect hemagglutination (IHA) test. The article describes the stages of red blood cells stabilization and sensitization and demonstrates the diagnostic significance of Fili stabilization method using formaldehyde as a fixative. The highest antibody titers (1:3000 and 1:4000) were received in hyperimmune sera of rabbits immunized with Mycobacterium bovis using a homologous diagnosticum. Practical importance of the sensitins homologous to the infection is shown during testing of 1,911 serum samples collected from animals of different categories (diseased; healthy and reacting to tuberculin; healthy and not reacting to tuberculin) with IHA test using diagnosticums produced from Mycobacterium bovis and Mycobacterium fortuitum. Based on the positive results of the IHA test, TB was diagnosed in 87.5% of animals originating from an infected farm during post-mortem examination. The results of the IHA test agreed with those of the intradermal tuberculin test in 37.7% of cases. Diagnostic antibody titers were found in 206 TB infected animals with no reaction to the intradermal test. However, the post-mortem examination revealed TB changes in internal organs. The obtained data suggest a possibility to use the IHA test to detect TB infected animals with non-specific reactions to tuberculin.

Evaluation of post-mortem diagnostic tests' sensitivity and specificity for bovine tuberculosis using Bayesian latent class analysis

2019 ◽  
Vol 125 ◽  
pp. 14-23
Author(s):  
Paulo Martins Soares Filho ◽  
Alberto Knust Ramalho ◽  
André de Moura Silva ◽  
Mikael Arrais Hodon ◽  
Marina de Azevedo Issa ◽  
...  
Keyword(s):  
Latent Class Analysis ◽  
Sensitivity And Specificity ◽  
Bovine Tuberculosis ◽  
Diagnostic Tests ◽  
Latent Class ◽  
Post Mortem ◽  
Class Analysis ◽  
Bayesian Latent Class Analysis

scholarly journals Testing cattle with Johnin: Being a report on the value of the intradermal test on cattle

1941 ◽  
Vol 41 (3) ◽  
pp. 297-319 ◽  
Author(s):  
Keyword(s):  
Bovine Tuberculosis ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Intradermal Test ◽  
Post Mortem ◽  
Wasting Disease ◽  
Post Mortem Examination ◽  
Prominent Symptom

In the last century a wasting disease of cattle in which diarrhoea was the prominent symptom was described by some veterinarians, but was at first often confused with tuberculosis although the distinctive lesions found in the latter disease were not present at post-mortem examination. However, it is only during the last forty years that Johne's disease has been clearly differentiated from bovine tuberculosis.

scholarly journals Post-mortem examination and laboratory-based analysis for the diagnosis of bovine tuberculosis among dairy cattle in Ecuador

2011 ◽  
Vol 101 (1-2) ◽  
pp. 65-72 ◽  
Author(s):  
Freddy Proaño-Pérez ◽  
Washington Benitez-Ortiz ◽  
Daniel Desmecht ◽  
Marco Coral ◽  
Julio Ortiz ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Bovine Tuberculosis ◽  
Post Mortem ◽  
Post Mortem Examination

An outbreak of Parasitic Necrosis in Turkeys caused by Plagiorchis laricola (Skrjabin)

1937 ◽  
Vol 15 (1) ◽  
pp. 35-36 ◽  
Author(s):  
Angus Foggie
Keyword(s):  
Northern Ireland ◽  
Post Mortem ◽  
Turkey Poult ◽  
Heavy Infection ◽  
Post Mortem Examination ◽  
Research Division ◽  
Veterinary Research

A turkey poult sent for post-mortem examination to the Veterinary Research Division, Ministry of Agriculture, Northern Ireland, was found to be suffering from a very heavy infection of a small fluke.

scholarly journals Performance of serological antibody tests for bovine tuberculosis in cattle from infected herds in Northern Ireland

2017 ◽  
Author(s):  
L. McCallan ◽  
C. Brooks ◽  
C. Couzens ◽  
F. Young ◽  
A.W. Byrne ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Skin Test ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Skin Testing ◽  
Gamma Interferon ◽  
Study Cohort ◽  
Post Mortem ◽  
Serological Tests

AbstractThe ability to accurately identify infected hosts is the cornerstone of effective disease control and eradication programs. In the case of bovine tuberculosis, caused by infection with the pathogenMycobacterium bovis, accurately identifying infected individual animals has been challenging as all available tests exhibit less than 100% discriminatory ability. Here we assess the utility of three serological tests and assess their performance relative to skin test (Single Intradermal Comparative Cervical Tuberculin; SICCT), gamma-interferon (IFNγ) and post-mortem results in a Northern Ireland setting. Furthermore, we describe a case-study where one test was used in conjunction with statutory testing.Serological tests using samples taken prior to SICCT disclosed low proportions of animals as test positive (mean 3% positive), despite the cohort having high proportions with positive SICCT test under standard interpretation (121/921; 13%) or IFNγ (365/922; 40%) results. Furthermore, for animals with a post-mortem record (n=286), there was a high proportion with TB visible lesions (27%) or with laboratory confirmed infection (25%). As a result, apparent sensitivities within this cohort was very low (≤15%), however the tests succeeded in achieving very high specificities (96-100%). During the case-study, 7/670 (1.04%) samples from SICCT negative animals from a large chronically infected herd were serology positive, with a further 10 animals being borderline positive (17/670; 2.54%). 9/17 of these animals were voluntarily removed, none of which were found to be infected (-lesions/-bacteriology) post-mortem; 1 serology test negative animal was subsequently lesion+ andM bovisconfirmed at slaughter.ImportanceEradication of bovine tuberculosis (bTB; caused byMycobacterium bovis) has remained elusive in a number of countries despite long-term coordinated test and cull programs. This can partially be explained by the limitations of available statutory tests; therefore supplementary test platforms that identify additional infected animals would be of significant utility. Overall, during our study three serological tests did not disclose a high proportion of animals as infected in high-risk cattle herds, and exhibited limited ability to disclose animals that were positive to the statutory skin test, the gamma interferon test (IFNγ), or were post-mortem confirmed withM. bovis. These serological tests could be used in a supplementary fashion to the statutory tests in particular circumstances; but may be of limited advantage where parallel use of IFNγ and skin testing is performed, as these tests together tended to disclose the majority of animals with post-mortem evidence of infection in our study cohort.

Prevalence of Bovine tuberculosis in Ethiopian slaughter cattle based on post-mortem examination

2008 ◽  
Vol 41 (5) ◽  
pp. 755-765 ◽  
Author(s):  
B. Demelash ◽  
F. Inangolet ◽  
J. Oloya ◽  
B. Asseged ◽  
M. Badaso ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Post Mortem ◽  
Post Mortem Examination ◽  
Slaughter Cattle

scholarly journals Efficiency of slaughterhouse surveillance for the detection of bovine tuberculosis in cattle in Northern Ireland

2016 ◽  
Vol 145 (5) ◽  
pp. 995-1005 ◽  
Author(s):  
A. V. PASCUAL-LINAZA ◽  
A. W. GORDON ◽  
L. A. STRINGER ◽  
F. D. MENZIES
Keyword(s):  
Risk Factors ◽  
Logistic Regression ◽  
Northern Ireland ◽  
Bovine Tuberculosis ◽  
Post Mortem ◽  
Univariable Analysis ◽  
Eradication Programme ◽  
Risk Status ◽  
Regression Modelling ◽  
Logistic Regression Modelling

SUMMARYPost-mortem examination continues to play an important surveillance role in the bovine tuberculosis (bTB) eradication programme in Northern Ireland. It is estimated that 18–28% of new bTB herd breakdowns are disclosed by the detection of bTB lesions in animals routinely slaughtered. The purpose of this study was to compare the performance of different slaughterhouses in Northern Ireland in detecting bTB-lesioned animals at routine slaughter (LRS) and to apply the findings to maximize the sensitivity of bTB slaughterhouse surveillance. Univariate statistical analysis on cattle slaughtered in Northern Ireland during 2011–2013 revealed that the risk of LRS disclosure varied between slaughterhouses, ranging from 0·08% to 0·54%. Furthermore, the risk of confirmation of these LRS as bTB varied between slaughterhouses, ranging from 57·9% to 72·4%. Logistic regression modelling of selected risk factors found that the risk of LRS disclosure increased with age, and was higher in purchased animals, during winter months, in animals coming from high bTB incidence areas and in animals slaughtered from herds with a bTB restriction in the last 2–3 years. Adjusting for these selected factors, the risk of LRS disclosure and bTB confirmation changed very little from the univariable analysis, suggesting that differences in disclosure risks between slaughterhouses were likely to be due to factors related to the slaughterhouses, rather than to the risk status of the animals presented. Examination of procedures within these slaughterhouses is recommended to identify ways that could increase the sensitivity of their bTB surveillance.

scholarly journals Evaluation using latent class models of the diagnostic performances of three ELISA tests commercialized for the serological diagnosis of Coxiella burnetii infection in domestic ruminants

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Thibaut Lurier ◽  
Elodie Rousset ◽  
Patrick Gasqui ◽  
Carole Sala ◽  
Clément Claustre ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Coxiella Burnetii ◽  
Latent Class ◽  
Latent Class Model ◽  
Diagnostic Errors ◽  
Latent Class Models ◽  
Serological Diagnosis ◽  
Diagnostic Tools ◽  
Conditional Dependence ◽  
Optimal Sample

AbstractELISA methods are the diagnostic tools recommended for the serological diagnosis of Coxiella burnetii infection in ruminants but their respective diagnostic performances are difficult to assess because of the absence of a gold standard. This study focused on three commercial ELISA tests with the following objectives (1) assess their sensitivity and specificity in sheep, goats and cattle, (2) assess the between- and within-herd seroprevalence distribution in these species, accounting for diagnostic errors, and (3) estimate optimal sample sizes considering sensitivity and specificity at herd level. We comparatively tested 1413 cattle, 1474 goat and 1432 sheep serum samples collected in France. We analyzed the cross-classified test results with a hierarchical zero-inflated beta-binomial latent class model considering each herd as a population and conditional dependence as a fixed effect. Potential biases and coverage probabilities of the model were assessed by simulation. Conditional dependence for truly seropositive animals was high in all species for two of the three ELISA methods. Specificity estimates were high, ranging from 94.8% [92.1; 97.8] to 99.2% [98.5; 99.7], whereas sensitivity estimates were generally low, ranging from 39.3 [30.7; 47.0] to 90.5% [83.3; 93.8]. Between- and within-herd seroprevalence estimates varied greatly among geographic areas and herds. Overall, goats showed higher within-herd seroprevalence levels than sheep and cattle. The optimal sample size maximizing both herd sensitivity and herd specificity varied from 3 to at least 20 animals depending on the test and ruminant species. This study provides better interpretation of three widely used commercial ELISA tests and will make it possible to optimize their implementation in future studies. The methodology developed may likewise be applied to other human or animal diseases.

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