Clicky

Most recent
 Data needed to achieve meaningful results in the 2013 badger culls
Added or updated 3 days ago
 Launch of farmer-led TB governance in New Zealand
Added or updated 5 days ago
 Gassing of badger setts
Added or updated 2 months ago
 Accuracy of the TB test for cattle
Added or updated 2 months ago
 Bovine TB in the UK, England, Ireland, Wales and New Zealand
Added or updated 2 months ago
 Did culling affect TB infection in badgers?
Added or updated 2 months ago
 Bovine TB in GB. Latest SAM data, maps and older VETNET data.
Added or updated 2 months ago
PDF icon Wildlife management and zoonotic infections. A one day symposium held at The Royal Society of Medicine, London on 17 November 2010.
Added or updated 2 months ago
PDF icon Badgers prefer cattle pasture but avoid cattle: implications for bovine tuberculosis control. R Woodroffe et al. Ecology Letters. 2016.
Added or updated 3 months ago
PDF icon Programme for the eradication of bovine Tuberculosis, bovine Brucellosis or sheep and goat Brucellosis (B. melitensis) for obtaining EU cofinancing. Submitted by the Republic of Ireland on 28th May 2015.
Added or updated 3 months ago
PDF icon Post-mortem Examination of TB Reactors (R), Inconclusive Reactors (IRs) and Direct Contacts (DCs): PRELIMINARY RESULTS
Added or updated 3 months ago
 An example of how badger culling in the UK is being cast in a negative light
Added or updated 3 months ago
PDF icon Standard requirements for the submission of programme for eradication, control and monitoring. Submitted 21 Sep 2016 by Rosanne Greene of DAFM of the Irish Republic to the European Commission.
Added or updated 4 months ago
PDF icon Ireland to be bovine TB free by 2030 under new Government plans - FarmIreland.ie. @farm_ireland. May 10 2018 6:00 AM
Added or updated 4 months ago
PDF icon Differences between bovine TB indicators in the IAA and the Comparison Area. First six years, 1st May 2010 to 30th April 2016.
Added or updated 4 months ago
PDF icon Results of Badger Vaccination Modelling Report. 3 February 2016. Rebecca Evans, Deputy Minister for Farming and Food.
Added or updated 4 months ago
 Bovine TB in Ireland
Added or updated 4 months ago
PDF icon Badgers removed in the Irish Republic
Added or updated 4 months ago
 Does badger culling make economic sense?
Added or updated 4 months ago
PDF icon Bovine TB Eradication Programme IAA Vaccination Project - Year 4 Report
Added or updated 4 months ago

Evidence of TB during post-mortem

Is an animal infected with bovine TB if bovine TB infection was not found in a post-mortem examination?

The following extracts explain why post-mortem examination does not reveal all incidences of infection.

About 6% of confirmed reactor cattle in GB show no grossly visible lesions at post-mortem examination. Given the high throughput of animals in slaughterhouses and the fact that many confirmed reactor cattle have only one or two small grossly visible lesions, or none, it is perhaps unrealistic to expect slaughterhouse inspection to provide anything other than cursory surveillance. This is not to underestimate its important role in protecting public health, but its role in surveillance is secondary to herd testing. 1

Q7. Negative culture results from the lab must mean no infection is present?
A7. No. Detection of M. bovis by culture is affected by many factors including the sampling process, with visibly lesioned animals giving a greater chance of detecting infection. Animals at early stages of disease and latently infected animals do not present with visible lesions at post-mortem and will result in some animals escaping detection.
2

5-10% of latently infected humans develop clinical tuberculosis during their lifetime through re-activation of the latent infection (re-activation tuberculosis). The argument that latently infected individuals (culturenegative NVL, skin test reactors for example) constitute a continuous and unpredictable source of reinfection, is equally valid for cattle as it is for human TB. At the early stages of infection, or in latently infected cattle, a period will occur when M. bovis appears to be absent because the bacillary load is not large enough to be detected by culture. In addition, the pathological changes caused by the bacilli are not yet profound enough to be detected during routine abattoir inspection. However, cellular immune responses will be detectable in these animals at an earlier stage of infection than the pathological changes caused by the disease (e.g.visible lesions), or before the bacterial loads exceed the numbers necessary to be able to culture M. bovis from tissue samples. 3

Q1. Is it true that skin test positive animals that show no signs of diseased tissue at post-mortem examination (known as NVL or no visible lesions) have never had the infection?
A1. The false positive rate for the skin test is very low (1 in 1000) and so it is very likely that any animal that tests positive is infected, regardless of whether this is confirmed at post -mortem.
2

References
  1. Final Report of the Independent Scientific Group on Cattle TB
  2. Bovine TB- the facts
  3. Government Veterinary Journal

Back to main site
Javascript is disabled