Performance of the single intradermal comparative tuberculin test in identifying cattle with tuberculous lesions in Irish herds

Costello, Eamon; Egan, John; Quigley, Frances; O’Reilly, Paul

doi:10.1136/vr.141.9.222

Cited by 47 publications

(30 citation statements)

References 8 publications

(12 reference statements)

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“…We take a diagnostic test sensitivity of p ϭ 2͞3, this value corresponding broadly to reports in the literature (12,13) to obtain the effective removal rate as r ϭ 1.3 yr Ϫ1 . Lower sensitivity would imply decreased r 1 , and it is clear from Eq.…”

Section: Numerical Results Based On Modelmentioning

confidence: 99%

Simple model for tuberculosis in cattle and badgers

Cox

Donnelly

Bourne

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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As an aid to the study of bovine tuberculosis (TB), a simple model has been developed of an epidemic involving two species, cattle and badgers. Each species may infect the other. The proportion of animals affected is assumed relatively small so that the usual nonlinear aspects of epidemic theory are avoided. The model is used to study the long-run and transient effect on cattle of culling badgers and the effect of a period without routine testing for TB, such as occurred during the 2001 epidemic of foot-and-mouth disease in Great Britain. Finally, by examining the changes in cattle TB over the last 15 years, and with some other working assumptions, it is estimated that the net reproduction number of the epidemic is Ϸ1.1. The implications for controlling the disease are discussed.animal ecology ͉ epidemiology ͉ mathematical model M athematical modeling of infectious disease, especially in humans, has a long history (1). Two very different kinds of dynamical model are simple outline and quasirealistic models. The former aim to capture the essence of a complex situation in a few key aspects and then to use these to explain the qualitative patterns of behavior to be expected and even to give semiquantitative predictions. Quasirealistic models, by contrast, aim to get much closer to reality by representing, almost inevitably in a model implemented by computer rather than by mathematical analysis, as many features of reality as is feasible. Despite the attractions of greater realism, a common problem with such models is the need to specify the values of a considerable number of forms of dependence and the numerical values of unknown parameters, often, as in the present instance, aspects about which little is known. The consequent need for extensive and systematic sensitivity analyses may undermine the usefulness of such models and mean that such data as are available are consistent with many different interpretations.In the present work we consider a deterministic multispecies transmission model of the former simpler type to describe Mycobacterium bovis infection in cattle and badgers. After setting out a fairly general model framework allowing both within-and between-species transmission, we look at a number of special situations corresponding in particular to interventions on one or other species. General Model SpecificationWe consider a reasonably homogeneous area such that at time t there are X 1 (t) ϭ C(t) infected cattle per km 2 and X 2 (t) ϭ B(t) infected badgers per km 2 . We suppose that the proportions of infected animals are relatively small, say Ͻ0.2, so that the nonlinear effects characteristic of epidemic theory, because of the depletion of the pool of susceptible animals, are not important. This assumption seems reasonable because reports of more than a small number of reactor cattle within individual herd breakdowns are rare. Also, we do not distinguish between infected and infectious animals, thus making the approximation that all infected animals of a particular species are equally infectious.A majo...

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Section: Numerical Results Based On Modelmentioning

confidence: 99%

Simple model for tuberculosis in cattle and badgers

Cox

Donnelly

Bourne

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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“…All animals within the chosen herds were tested except for recently calved cows (within two months post-partum) and calves less than six months old because of immuno-suppression in lactating cows and high maternal antibodies in calves which desensitise them to tuberculin (Costello et al 1997;Shirima et al 2003). Placed ear tags and skin tattoos were used to identify test animals and herdsmen had also memorised features for each animal under their care (e.g., vocals, body markings, mannerisms).…”

Section: Tuberculin Skin Tests In Cattle: Study Area and Selection Ofmentioning

confidence: 99%

Prevalence of bovine tuberculosis in cattle in the highlands of Cameroon based on the detection of lesions in slaughtered cattle and tuberculin skin tests of live cattle

Awah-Ndukum¹,

Kudi²,

Bradley³

et al. 2012

Vet. Med. - Czech

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Bovine tuberculosis (TB) is an important neglected zoonosis in Cameroon, where many communities depend on their livestock for livelihood and the incidence of human TB and TB-HIV/AIDS co-infection are high and increasing annually. The aim of this study was to estimate the prevalence of bovine TB in cattle in the highlands of Cameroon. The magnitude and trend of detecting TB lesions in slaughtered cattle (1994 to 2010) and tuberculin skin tests (TST) in 2853 cattle (84 herds) of 39 livestock rearing communities were analysed. Of 129 165 slaughtered cattle inspected, 599 (0.46%; 95% CI: 0.43%-0.50%) showed suspected TB lesions among a total of 983 (0.76%; 95% CI: 0.71%-0.81%) identified pathologies. The monthly TB detection rates ranged from 0.30% (95% CI: 0.20%-0.40%) to 0.81% (95% CI: 0.64%-0.98%) and annual rates from 0.04% (95% CI: 0%-0.11%) to 1.46% (95% CI: 1.22%-1.69%). The rates were not affected (P < 0.05) by season and fluctuating peaks were also recorded. The comparative TST revealed that bovine TB was widely distributed in live cattle (4.67%; 95% CI: 3.89%-5.44%) and was higher (χ 2 = 17.50, P ≤ 0.001) in the Western highlands than Adamawa plateaux.Comparative TST bovine TB reactors were higher (P < 0.05) in cattle managed in semi-intensive and beef production systems compared to the others. Animals in small herds showed higher (χ 2 = 4.283, P = 0.038) rates than those in large herds. Bovine TB prevalence in exotic/upgraded cattle was comparable to that of the Red Bororo zebu but higher than the rates in Guadali (χ 2 = 4.971, P = 0.026) and White Fulani (χ 2 = 5.6, P = 0.018) zebus.Among the indigenous zebus, the rate was higher in Red Bororo than the Guadali (χ 2 = 6.244, P = 0.012) and White Fulani (χ 2 = 6.568, P = 0.010). Sex did not influence (χ 2 = 0.410, P = 0.522) bovine TB prevalence in this study but diagnosis of the disease was higher (χ 2 = 5.787; P = 0.016) among adult/older cattle than in younger animals. Further analysis of the TST responses revealed that atypical mycobacterial infections was widespread and 6.83% of tested animals showed positive reactions at both bovine and avian tuberculin injection sites and a strong association (χ 2 = 2.512; P = 0.113) between skin responses to both tuberculins. The study confirms that bovine TB is prevalent in live cattle and meat production abattoirs in Cameroon and we recommend strict a interpretation of TST results for maximum diagnosis of the disease in the local environment. A need for comprehensive investigation of the molecular epidemiology, zoonotic risks and the public health importance of bovine TB in Cameroon cannot be overemphasised.

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“…If exclusion of cross-reactivity with M. avium is required, a parallel injection of M. avium tuberculin is used. Literature data indicate that the sensitivity (% of infected animals correctly identified) of the M. bovis tuberculin skin test can vary with an average of around 90%, while the specificity (% of uninfected animals correctly identified) can be as high as >99.9% (Wilesmith et al, 1982;Costello et al, 1997). The meat safety implications of the sensitivity of tuberculin test being less than 100% include that during on-farm testing the TB infection with M. bovis can remain undetected in some animals in multiple-reactors herds, or in herds containing single reactors.…”

Section: Alternative Methods For Detection Of Bovine Tuberculosismentioning

confidence: 99%

Opinion of the Scientific Panel on biological hazards (BIOHAZ) on Revision of Meat Inspection for Beef raised in Integrated Production Systems

2005

EFSA Journal

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Performance of the single intradermal comparative tuberculin test in identifying cattle with tuberculous lesions in Irish herds

Cited by 47 publications

References 8 publications

Simple model for tuberculosis in cattle and badgers

Simple model for tuberculosis in cattle and badgers

Prevalence of bovine tuberculosis in cattle in the highlands of Cameroon based on the detection of lesions in slaughtered cattle and tuberculin skin tests of live cattle

Opinion of the Scientific Panel on biological hazards (BIOHAZ) on Revision of Meat Inspection for Beef raised in Integrated Production Systems

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