Investigations and implications of associations between mycobacterial purified protein derivative hypersensitivity and MAP-antibody ELISA in Irish dairy cows

Kennedy, Aideen; Byrne, N.; O'Mahony, John B.; Sayers, Rí­ona

doi:10.1016/j.rvsc.2017.01.018

Cited by 12 publications

(18 citation statements)

References 8 publications

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“…This is a much less likely explanation for multiple IR results in the same animal. There could be a trend toward repeat IR animals never developing a positive reaction to the SICCT test despite TB infection due to immunomodulatory factors such as genetics or pre-exposure to Mycobacterium avium [18][19][20]. Amos et al (2013) investigated a possible effect of a particular TB genotype, which was noted to be prevalent in non-reactor animals.…”

Section: Discussionmentioning

confidence: 99%

Exploring the Risk Posed by Animals with an Inconclusive Reaction to the Bovine Tuberculosis Skin Test in England and Wales

May

Prosser

Downs

et al. 2019

Veterinary Sciences

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The single intradermal comparative cervical tuberculin (SICCT) test is the primary test for ante-mortem diagnosis of bovine tuberculosis (TB) in England and Wales. When an animal is first classified as an inconclusive reactor (IR) using this test, it is not subject to compulsory slaughter, but it must be isolated from the rest of the herd. To understand the risk posed by these animals, a case-control study was conducted to measure the association between IR status of animals and the odds of them becoming a reactor to the SICCT at a subsequent test. The study included all animals from herds in which only IR animals were found at the first whole herd test in 2012 and used data from subsequent tests up until the end of 2016. Separate mixed-effects logistic regression models were developed to examine the relationship between IR status and subsequent reactor status for each risk area of England and for Wales, adjusting for other explanatory variables. The odds of an animal becoming a subsequent reactor during the study period were greater for IR animals than for negative animals in the high-risk area (odds ratio (OR): 6.85 (5.98-7.86)) and edge area (OR: 8.79 (5.92-13.04)) of ). In the low-risk area of England, the odds were 23 times greater, although the confidence interval around this estimate was larger due to the smaller sample size (11-48, p < 0.001). These findings support the need to explore differential controls for IR animals to reduce the spread of TB, and they highlight the importance of area-specific policies.

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Section: Discussionmentioning

confidence: 99%

Exploring the Risk Posed by Animals with an Inconclusive Reaction to the Bovine Tuberculosis Skin Test in England and Wales

May

Prosser

Downs

et al. 2019

Veterinary Sciences

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“…It is plausible that such M. avium PPD reactors have been exposed to non‐ M. bovis mycobacteria, including M. avium subsp. paratuberculosis (MAP) the aetiological agent of Johne's disease (JD; Ameni et al., ; Gilardoni et al., ; Kennedy et al., ) or other mycobacteria (e.g., M. avium subsp. avium ).…”

Section: Discussionmentioning

confidence: 99%

“…Part of the goal of this study was to investigate potential interactions between endemic diseases, their impacts on the SICCT test and post‐mortem M. bovis pathological progression. Three exposures were considered in this study, as there was evidence in the literature to suggest they may impact TB diagnostics or progression—BVDV (Kao et al., ), liver fluke infection ( Fasciola hepatica ; Claridge et al., ) and non‐bTB Mycobacterium exposure (measured using the M. avium PPD tuberculin reaction; Gilardoni, Paolicchi, & Mundo, ; Kennedy, Byrne, O'Mahony, & Sayers, ). Details can be found in Byrne, Graham et al.…”

Section: Methodsmentioning

confidence: 99%

“…Note, that the third liver fluke metric is related to both categories (i) and (ii) and therefore not independent of these variables. Potential exposure to non‐bTB Mycobacterium was assessed using the relative reaction size to the bovine and M. avium tuberculin used during the disclosing test (Ameni et al., ; Bermingham et al., ; Gilardoni et al., ; Kennedy et al., ). We considered M. avium PPD reactors as animals with negative PPD b− PPD a tuberculin reactions (PPD b− PPD a < 0 mm) and as potentially indicative of exposure to non‐bTB Mycobacterium, including M. avium subsp.…”

Section: Methodsmentioning

confidence: 99%

“…We considered M. avium PPD reactors as animals with negative PPD b− PPD a tuberculin reactions (PPD b− PPD a < 0 mm) and as potentially indicative of exposure to non‐bTB Mycobacterium, including M. avium subsp. paratuberculosis the aetiological agent of Johne's disease in cattle (Ameni et al., ; Gilardoni et al., ; Kennedy et al., ).…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Modelling the variation in skin-test tuberculin reactions, post-mortem lesion counts and case pathology in tuberculosis-exposed cattle: Effects of animal characteristics, histories and co-infection

Byrne

Graham

Brown

et al. 2018

Transbound Emerg Dis

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Correctly identifying bovine tuberculosis (bTB) in cattle remains a significant problem in endemic countries. We hypothesized that animal characteristics (sex, age, breed), histories (herd effects, testing, movement) and potential exposure to other pathogens (co-infection; BVDV, liver fluke and Mycobacterium avium reactors) could significantly impact the immune responsiveness detected at skin testing and the variation in post-mortem pathology (confirmation) in bTB-exposed cattle. Three model suites were developed using a retrospective observational data set of 5,698 cattle culled during herd breakdowns in Northern Ireland. A linear regression model suggested that antemortem tuberculin reaction size (difference in purified protein derivative avium [PPDa] and bovine [PPDb] reactions) was significantly positively associated with post-mortem maximum lesion size and the number of lesions found. This indicated that reaction size could be considered a predictor of both the extent (number of lesions/tissues) and the pathological progression of infection (maximum lesion size). Tuberculin reaction size was related to age class, and younger animals (<2.85 years) displayed larger reaction sizes than older animals. Tuberculin reaction size was also associated with breed and animal movement and increased with the time between the penultimate and disclosing tests. A negative binomial random-effects model indicated a significant increase in lesion counts for animals with M. avium reactions (PPDb-PPDa < 0) relative to non-reactors (PPDb-PPDa = 0). Lesion counts were significantly increased in animals with previous positive severe interpretation skin-test results. Animals with increased movement histories, young animals and non-dairy breed animals also had significantly increased lesion counts. Animals from herds that had BVDV-positive cattle had significantly lower lesion counts than animals from herds without evidence of BVDV infection. Restricting the data set to only animals with a bTB visible lesion at slaughter (n = 2471), an ordinal regression model indicated that liver fluke-infected animals disclosed smaller lesions, relative to liver fluke-negative animals, and larger lesions were disclosed in animals with increased movement histories.

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The interpretation of serial Johne’s disease milk antibody results is affected by test characteristics, pattern of test results and parallel bovine tuberculosis testing

Barden

Smith

Higgins

2020

Preventive Veterinary Medicine

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Investigations and implications of associations between mycobacterial purified protein derivative hypersensitivity and MAP-antibody ELISA in Irish dairy cows

Cited by 12 publications

References 8 publications

Exploring the Risk Posed by Animals with an Inconclusive Reaction to the Bovine Tuberculosis Skin Test in England and Wales

Exploring the Risk Posed by Animals with an Inconclusive Reaction to the Bovine Tuberculosis Skin Test in England and Wales

Modelling the variation in skin-test tuberculin reactions, post-mortem lesion counts and case pathology in tuberculosis-exposed cattle: Effects of animal characteristics, histories and co-infection

The interpretation of serial Johne’s disease milk antibody results is affected by test characteristics, pattern of test results and parallel bovine tuberculosis testing

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