Focus on the disease not ‘scape goats’?

NATIONAL BADGER DAY : TUESDAY 6 OCTOBER 2015

Badger & mayweed

A report has been draw to our attention and is worthy perhaps of a wider audience, click on the heading below for the full version. 

Despite the continuing call for abandonment of the expensive cull the Government persist in wholesale slaughter, in parallel as reported recently they also seek to consult on the reform of cost protection for Judicial Review applications by the public or environmental organisations and charities.  The phrase ‘evidence-based’ seems to have lost favour when it comes to addressing inconvenient issues?

Cattle testing key to bovine TB control & how Wales achieved a major decline in bTB

The role of cattle testing is fundamental to the control of the disease.

Accurate diagnosis is crucial to identify disease and remove infected cattle to prevent the disease spreading. But the SICCT test used to diagnose infected cattle can miss up to 1 in 5, or about 20%, of infected animals.

This means that infected animals can still be present in the herd when movement restrictions are lifted and Officially Tuberculosis Free (OTF) status is regained

Because of this limited sensitivity, intensive and repeated testing is needed to identify, locate and remove infected animals to prevent them spreading the disease within the herd or to other herds.

In the Area Eradication Strategy(AES) of 1950’s & 60’s the number of reactors slaughtered was brought down in just 4 years from 25,571 in 1959, to 5,901 in 1963.

This reduction was achieved by using a high testing intensity applied across the UK, in conjunction with strict movement controls and tight bio-security.   In 1959 over 11 million tests were carried out.

With the AES of the 1950’s & 60’s, the high level of testing was maintained for many years, and by 1976 the number of reactors slaughtered because of the disease had fallen to 1,058

By 1982 the number of reactors slaughtered had fallen to 569, but still circa 2.5 million tests were being carried out

But between the late 1980’s and 2006 various changes to the testing regime led to the re-establishment of the disease due to:

  • Major reduction in testing intensity
  • The relaxation of movement controls
  • The move to 2, 3 and 4 yearly testing which failed to identify emerging disease
  • Outbreak of BSE which required re-stocking, which was carried out without any pre-movement testing, and often with cattle not under annual testing
  • The abandonment of testing during the FMD epidemic
  • Re-stocking post FMD with cattle that had missed their tests, without any pre-movement testing and which were also moved to areas of the country not under annual testing, therefore any infection present may not have been identified for a considerable period of time, and also allowed for significant onward transmission
  • The scaling back of testing generally which allowed un-identified infected cattle to be moved, traded, etc leading to an expansion in disease incidence

These changes in the testing regime resulted in an ever increasing spread of infection. By 2012, although the incidence of disease was much higher than during the AES, (37,000 reactors slaughtered) only just over 8 million tests were carried out.

So currently, despite a much higher incidence of disease now, (37,000 reactors in 2012) the number of tests still lags far below the level needed to identify and remove all infected cattle.

DEFRA’s response:       In the last 2 years Defra has begun to greatly increase the number, frequency and effectiveness of the testing regime by:

  • Increasing the areas of the country under annual testing
  • Using gamma interferon testing to supplement the SICCT test
  • Zero-tolerance of overdue tests
  • Greater use of severe interpretation of test results
  • Treating inconclusive reactors as confirmed cases

These measures are beginning to take effect, with the number of cattle slaughtered in 2013 14% below that for 2012.  In Wales, which moved to annual testing in 2008 and has tightened up its testing programme, the number of cattle slaughtered in 2013 was 34% down on the number slaughtered in 2012.   Wales has nearly halved the number of cattle slaughtered per annum since 2009; from 11,671 in 2009 to 6,102 in 2013. This represents a very significant reduction of 48% in just 4 years.

https://www.gov.uk/government/publications/incidence-of-tuberculosis-tb-in-cattle-in-great-britain

In addition, other measures such as pre-movement testing, re-introduced in 2006 and 2007, have also identified infected cattle prior to movement and resulted in limiting the onward transmission of disease.

The level and frequency of testing, now introduced by Defra, is beginning to take effect, and should replicate the reduction in disease incidence as shown during the AES.

SICCT test limitations

Also Defra has recognised that the SICCT test (Single Intradermal Comparative Cervical Tuberculin test) has a variable sensitivity, which means that it can miss up to circa 20% of infected animals which are either in the early or late stages of disease.

This means that infected animals can still be present in the herd when movement restrictions are lifted and Officially Tuberculosis Free (OTF) status regained.

As a result Defra, has ramped up of the frequency of tests, increased the areas under annual testing and introduced gamma interferon testing as a supplementary test.

However, the limitations of the SICCT test do not appear to have been made clear to either farmers or those involved in the livestock industry. Indeed the NFU is silent on the matter in its advice to farmers.

Given the SICCT test limitations it is crucial to introduce and maintain high levels of testing across the country and ensure pre and post movement testing is carried out to identify, locate and remove latent infection before it can be passed on to other animals..

Such intensive testing regimes are onerous for the farming industry, but if the need for them could be carefully explained, then all involved would understand the need for these measures and how they will bring the disease under control.

Further information: including the AWG papers submitted to Defra, are available from: Animal Welfare Group, Co-ordinating Office: 3 The Common, Siddington, Cirencester, Glos GL7 6EY.   Tel: 01285 656812 / 01285 644319      Email janbayley@aol.com

The Government statistics available in Incidence of TB in cattle in Great Britain – statistical notice (data to June 2015) make interesting reading when considered against the revised costs of the cull (in excess of £16m or the equivalent of £6,775 per badger), one might ponder the value of the spend of public funds when there has been a demonstrable improvement in Wales through the adoption of an improved testing regime.  If better bio-security and vaccination were added to the tool kit as well, then a collaborative address would deliver better for both the dairy farmer and their customers as well as poor ‘brock’, a convenient scape goat?

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