Friday, February 11, 2005

ISG Statement on skin test - Miss - Herd??

The ISG (Independent Scientific Group) has advised government to take tougher controls to combat the spread of tuberculosis cattle to cattle.

The full report can be viewed at
but the gist is that the intradermal tuberculin skin test "fails to accurately identify infected animals" and therefore enhanced cattle to cattle controls are needed.

We have already reported the Seminar 16th. September 2004, at whch John Bourne of the ISG told the great and the good, including Mr. Bradshaw, that the intradermal skin test was "an excellent herd test".
So was his statement miss-herd?

To be fair he quantified it with the proviso that "it was not an effective individual animal test".
(see later)

And Mr. Bradshaw confirmed both statements in PQ's (archived).

8 Dec 2003 Col 218W
"The tuberculin skin test has been compulsory in Britain since 1950. This is a test prescribed by the for OIE (Office of International Epizootics) for international trade, as well as under EU directive 64/432/EEC."

As the rest of the world considers that the intradermal skin test is the gold standard for measuring tuberculosis infection in cattle, any other diagnostic tool can only be supplementary to it.

30th Jan 2004 Col 540W
To ask the Secretary of State (pursuant to her answer above) how many countries use the current skin sensitivety test, and how many have reported problems with it.
"All countries have either eradicated, or have a programme to control bovine tuberculosis using one or more forms of the skin test"
"The Government are not aware of any country that has replace the skin test as a primary test for bovine tuberculosis".

On its effectiveness when used on a single animal, Mr. Bradshaw confirmed;

25th March 2004 Col 988W
"Any test with imperfect sensitivety (The skin test has 98% as a herd test but 68% on a single individual) when applied more than once to a single animal, will cause the overall sensitivety to rapidly approach 100 percent."

Which is why when a cattle herd test reveals reactors to the skin test which subsequently become confirmed as carrying tuberculosis, TWO herd skin tests are required to lift the restriction - always assuming that 'somebody' has ordered the tuberculin, which must now be used 'judiciously' as it is short supply.
(see post below.)

Strange that - if it's all a waste of time anyway.

The ISG continues " Regardless of the role of wildlife intervention, we (the ISG) believe it is essential that more effective disease control measures directed at cattle, should be put in place without further delay"

And when we've done that..??

What part of "96 percent drop in herds under restriction" (Irish Trials) does the ISG not understand?
And Battersea's battling Boadicea - the lovely Elaine has said "Badger culling only reduces TB in cattle if every single badger is exterminated". (see posts below)

"Regardless of the role of wildlife intervention..."

How can we be regardless of it, when it accounts for 96 percent of the problem?
How much does the ISG need continued funding?


Anonymous said...

Why on earth should we be FAIR to John Bourne and the ISG???

Richard said...

"Furious And Indignant, Really" = FAIR

Matthew said...

Thanks. We could come up with all manner of adjectives.
Seriously p*****d off springs to mind!