There are times when the predictable is so obvious that, like the ‘elephant in the room’, it is unseen by those closest to the beast. We saw it with the previous Industry Strategy on bTb, when a three pronged attack on the disease, worded to happen simultaneously, together and concurrently was whittled down to two parts acceptance by government - and the appallingly unnecessary, polemic ‘consultation’ which predictably and conveniently kicked any action on infected badgers into the long grass. Pre movement testing, and tabular valuation stay, and as we have said, Defra got its ‘quid’ but failed to deliver the ‘pro quo’.
Last week, industry ‘stakeholders’ – how we hate that word – met in London to thrash out yet another Industry Strategy. The core of the agreement is as follows:
* That a Strategy working group be set up, aligned with DVM areas involving vets, farmers, the SVS and other ‘stakeholders’, to advise on policy for the area and create local Tb management groups.
* Licences would be applied for to cover the area – by individual farmers or for a designated area is by no means clear at this stage – and culling would be carried out by contractors employed by landowners.
* First choice methods would be cage traps and shooting , with CO gassing and occasionally stop snaring , when these methods are approved.
* Initially culling to be focussed in hot spot areas, within a framework of larger control area of up to 300 sq km and using if possible, hard geographical boundaries.
Other points in the Strategy outline deal with vague reference to those words beloved of government;
* Partnerships, provision of resources, industry and Government working together, focus and public information. We are surprised they missed out 'holistic' . Has that one fallen off the radar?
Full story on this link:
http://www.farmersguardian.com/story.asp?sectioncode=1&storycode=4178
So what happened to the last initiative and why should this one be any different ? Well, for a start, Defra have their pre movement testing, paid for by farmers. No sunset clause on it, and at a confirmed reactor rate of about 120 found out of 102,000 cattle tested, not a value for money exercise either – but then it is not Defra’s money.
They also have tabular valuation, the second tranche of the original three pronged attack, but with no action whatsoever on the maintenance reservoir of bTb in wildlife, and despite the alleged ‘drop’ in detection – we don’t buy ‘drop in incidence’ – farmers are still unable to obtain bTb insurance to cover higher value animals – at any price. Insurance cover should have been the pay off for returning to tabular valuation, but ‘exposure to risk is too great’ the man-from-the-Pru still says.
So what can be the lever this time? As our readers will have realised by now, we have a disturbingly cynical view of any weasel words from either Defra or the NFU that mention ‘partnership’. It usually means that Government want something, and need ‘industry’ support to sell what they want, to farmer members. – and the rest of us. The Minister says 'Jump', and the industry 's finest from the other side of their politically revolving door answer "How high?". In Parliamentary questions (archived on this site) our Ben, yup he’s still there bless him, (doesn’t want to be, but let that pass) spoke of ‘rationalisation’ of disease compensation; that was about 18 months before he achieved it via tabular valuations.
And on 31st March 2004, Column 1462W, Mr. Bradshaw, bruised from his FMD carnage and under not inconsiderable pressure from the Treasury with bTb costs spiralling at a 20 per cent growth rate per year, answered a question on disease levies, thus:
"The levy we have in mind would be raised on a per head basis, on all animals susceptible to any disease covered by the levy fund. Different rates of levy would be set for different categories of animals, in line with the categories which are set for the compensation regime".
You see where we’re coming from? The authors of this site have no problem in principle with levies – providing, and it is a big proviso – that government take their part of this much vaunted ‘partnership’ seriously. Prevention and insurance should be first choice, and would be if this disease - bTB - was under control. But we understand that even a proposal of a shared ‘responsibility’ between the Insurance companies and such industry levies, overseen by Defra, was laughed out of court a couple of years ago. That was a ‘No’ then.
So what have we got this time? Another Industry strategy working as a Trojan horse for unpopular measures, while Government have no intention whatsoever in delivering their half of the bargain? And what a bargain! Examined carefully, we see ‘farmer’ licenses and ‘farmer’ employed contractors using cage traps. And over an area of 300 sq km, when the diminutive John Bourne achieved his wonderful exercise in badger dispersal in just 100 ?? And ‘farmers’ will be paying for the privilege, when control of bTb ( a Grade 3 pathogen) is totally and completely Defra’s responsibility. Absolutely brilliant.
And the pay off this time? We think levies. Sold to a gullible and politically lightweight industry as a ‘joint initiative’ against a promise vaguely and certainly no time soon, of badger control by farmers. Been there, done that. Got the pre movement testing, and tabular valuation. But no insurance offers and no sick badgers sorted. And we see no reason to suppose this will be any different. The farming 'industry', aka the NFU, has a history of taking hard talk to the wire. But no further. And government know that, and use it. Unfortunately we now have a complete lack of HM's Opposition, since Owen Paterson's foray into battle with his questions, visits to see other country's solutions and enquiries into PCR technology. In Parliamentary Questions, he asked about the influence of these populous 'stakeholder' focus groups. Ben's enlightening answer should be "engraved on the hearts of all who take part - preferably without anaesthetic", a highly descriptive phrase plagiarised from our partner Richard, on www.eu.referendum.blogspot
27th January 2004: Col 246W
"Ministers consider carefully the advice of these bodies in formulating policy. However, there is no requirement for Ministers or the Department to abide by their advice, nor do these bodies have any formal power to veto departmental proposals".
That would seem pretty clear. You do as you're told, and we do as we like - and we do not like culling badgers. Ever. But we are quite happy to let 'farmers' do it for us. And pay for it. And they'll also pay a levy for the privilege.
Game, set and match to Defra.
Thursday, August 31, 2006
Friday, August 18, 2006
More on 'Going Dutch'.
A surf around the website of the makers of ID Lelystad tuberculin, imported since June 2005 as a 'stopgap' measure when VLA's production facility at Weybridge encountered problems, turned up some interesting kinks in the does-it-work v. doesn't-it-work conundrum.
As you will see from our posts below, the CVO is blaming her vets, both LVI's and SVS for 'testing procedures' which she says are not to the book. That these 'procedures' include such offences as not measuring the skin on jab day or measuring only one site, is included in the critism. I don't think that the basal skin measurement is going to alter too much in 72 hours, and most vets check it again when measuring anyway, so how that invalidates the test, I fail to see, but let that pass. Positioning the needle to deliver the antigen sub cutaneously instead of intradermally may also skew results - but that has not just happened in the last few months.
She has also studiously ignored the 2mm 'tightening' up to the test interpretation chart on oedemous reactions, introduced by her Department in February and certainly she has completely buried the comment in her report, relating to that 2mm difference; that it will "mean 24 per cent of incidents are missed, or detected later".
But on the CIDC Lelystad website, a comment on antigen sensitivety caught our eye - or the eagle eye of our Cornish contributer Matthew 1, to be precise. See Tuberculin Principle
The potency /level of both avian and bovine antigen in the Weybridge produced product was 2,500 iu/dose. And although both bovine antigens originate from UK supplied AN5 strain, the product which VLA imported from CIDC Lelystad was 2500 iu/dose on the avian antigen, but 3000 iu/dose on the bovine. But that isn't the whole story.
According to the Dutch website;
" In eradication programmes (when the prevalence of TBC infected cattle is significant) the use of Bovine Tuberculin PPD 2000 is recommended. In herds free of TBC, the use of Bovine Tuberculin 5000 is recommended, to increase the sensitivity of the test."
So ID Lelystad advise increasing the potency of bovine antigen for more sensitivity. But has that sensitivity at whatever level, been developed to find Dutch bTb strains, or the UK's?
More on the Dutch product at their : page: Tuberculin
On another part of the Dutch Animal Health site is a comment that using just the intradermal skin test and slaughter of reacters, the Netherlands achieved 'official bTb free status' some years ago, and as such, can now just undertake slaughterhouse surveillance only. The report was 2000, but said that Holland now did no routine testing unless a reactor is found at slaughter, and then skin tests are done on the host herd and any contiguous herds, backed up with PCR for speedy results. Well, well, well.
Amazing what the intradermal skin test can achieve, "in the absence of a wildlife reservoir". And not too much sympathy or patience with our troubles I suspect.
As you will see from our posts below, the CVO is blaming her vets, both LVI's and SVS for 'testing procedures' which she says are not to the book. That these 'procedures' include such offences as not measuring the skin on jab day or measuring only one site, is included in the critism. I don't think that the basal skin measurement is going to alter too much in 72 hours, and most vets check it again when measuring anyway, so how that invalidates the test, I fail to see, but let that pass. Positioning the needle to deliver the antigen sub cutaneously instead of intradermally may also skew results - but that has not just happened in the last few months.
She has also studiously ignored the 2mm 'tightening' up to the test interpretation chart on oedemous reactions, introduced by her Department in February and certainly she has completely buried the comment in her report, relating to that 2mm difference; that it will "mean 24 per cent of incidents are missed, or detected later".
But on the CIDC Lelystad website, a comment on antigen sensitivety caught our eye - or the eagle eye of our Cornish contributer Matthew 1, to be precise. See Tuberculin Principle
The potency /level of both avian and bovine antigen in the Weybridge produced product was 2,500 iu/dose. And although both bovine antigens originate from UK supplied AN5 strain, the product which VLA imported from CIDC Lelystad was 2500 iu/dose on the avian antigen, but 3000 iu/dose on the bovine. But that isn't the whole story.
According to the Dutch website;
" In eradication programmes (when the prevalence of TBC infected cattle is significant) the use of Bovine Tuberculin PPD 2000 is recommended. In herds free of TBC, the use of Bovine Tuberculin 5000 is recommended, to increase the sensitivity of the test."
So ID Lelystad advise increasing the potency of bovine antigen for more sensitivity. But has that sensitivity at whatever level, been developed to find Dutch bTb strains, or the UK's?
More on the Dutch product at their : page: Tuberculin
On another part of the Dutch Animal Health site is a comment that using just the intradermal skin test and slaughter of reacters, the Netherlands achieved 'official bTb free status' some years ago, and as such, can now just undertake slaughterhouse surveillance only. The report was 2000, but said that Holland now did no routine testing unless a reactor is found at slaughter, and then skin tests are done on the host herd and any contiguous herds, backed up with PCR for speedy results. Well, well, well.
Amazing what the intradermal skin test can achieve, "in the absence of a wildlife reservoir". And not too much sympathy or patience with our troubles I suspect.
Wednesday, August 16, 2006
Tb Policy and the badger culling trials.
In a letter to the Veterinary Record, August 12th., eight leading bTb veterinary experts continue to pile the pressue on the RBCT, or to be more precise, the Krebs’ exercise in badger dispersal.
Responding to a letter from the Chairman, Lord High Executioner, Judge and Jury of the ISG and the trial, Professor John Bourne, Messrs. McDiamid, Daykin, Smith, Ashton, Davies, Turnbull, Muirhead and Gallagher write that:
"…the use of ‘robust statistical methods’ will not derive the correct assumptions from flawed basic data."
They point out that:
"A high trapping efficiency was fundamental to the proper conduct of the trial, yet Defra, whose staff carried out the actual trapping at the direction of the ISG, conceded a very low efficiency of 20 – 60 per cent". And they remind Professor Bourne of the evidence given to the EFRA committee by one of his own Wildlife Team, in which he describes the poor conduct of the trials.
Using answers to Parliamentary Questions archived on this site, they remind the good Professor that during his badger ‘culling’ trial, "…of 15, 666 traps set, 8981 had been interfered with (57 percent) and a further 1827 (12 percent ) were stolen up to October 2003. And in April 2004, the Minister revealed that the trapping efficiency had been as low as 30 percent" .
They point out that, in their opinion, "that the trials had been compromised as well as the trapping approach, seems difficult to refute, despite the ISG’s protestations".
"While the ISG claims its trials were ‘robust’, the grossly inefficient culling methodology caused social disruption and dispersal of infected badgers on a vast scale, unseen in previous trials" (This was our contributer’s experience too - from Staffordshire to Cornwall.)
The letter concludes by reminding readers of previous work all of which officially recognises the badger as a maintenance host of bTb in the UK, a fact which Bourne and his colleagues tend to skate over with a euphemistic note that "badgers contribute to Tb in cattle", while applying their collective concentration to more cattle based measures.
"It (the ISG) confines its recommendations to ‘more vigorously adopted and applied cattle based measures’. Yet we know from earlier work, not always appreciated by the ISG, that cattle have been acting as sentinels of localised disease in badger communities.
Detection and slaughter of sentinels with even greater vigour, yet not addressing the source they are signalling, must be one of the most irrational epidemiological concept yet. We reiterate our warning that the ISG’s advice based these flawed ‘trials’ must be treated with extreme caution. It is also noteworthy that since 1998, the bTb problem has deteriorated so seriously that herd breakdowns have returned to a level not seen since the 1950’s."
Responding to a letter from the Chairman, Lord High Executioner, Judge and Jury of the ISG and the trial, Professor John Bourne, Messrs. McDiamid, Daykin, Smith, Ashton, Davies, Turnbull, Muirhead and Gallagher write that:
"…the use of ‘robust statistical methods’ will not derive the correct assumptions from flawed basic data."
They point out that:
"A high trapping efficiency was fundamental to the proper conduct of the trial, yet Defra, whose staff carried out the actual trapping at the direction of the ISG, conceded a very low efficiency of 20 – 60 per cent". And they remind Professor Bourne of the evidence given to the EFRA committee by one of his own Wildlife Team, in which he describes the poor conduct of the trials.
Using answers to Parliamentary Questions archived on this site, they remind the good Professor that during his badger ‘culling’ trial, "…of 15, 666 traps set, 8981 had been interfered with (57 percent) and a further 1827 (12 percent ) were stolen up to October 2003. And in April 2004, the Minister revealed that the trapping efficiency had been as low as 30 percent" .
They point out that, in their opinion, "that the trials had been compromised as well as the trapping approach, seems difficult to refute, despite the ISG’s protestations".
"While the ISG claims its trials were ‘robust’, the grossly inefficient culling methodology caused social disruption and dispersal of infected badgers on a vast scale, unseen in previous trials" (This was our contributer’s experience too - from Staffordshire to Cornwall.)
The letter concludes by reminding readers of previous work all of which officially recognises the badger as a maintenance host of bTb in the UK, a fact which Bourne and his colleagues tend to skate over with a euphemistic note that "badgers contribute to Tb in cattle", while applying their collective concentration to more cattle based measures.
"It (the ISG) confines its recommendations to ‘more vigorously adopted and applied cattle based measures’. Yet we know from earlier work, not always appreciated by the ISG, that cattle have been acting as sentinels of localised disease in badger communities.
Detection and slaughter of sentinels with even greater vigour, yet not addressing the source they are signalling, must be one of the most irrational epidemiological concept yet. We reiterate our warning that the ISG’s advice based these flawed ‘trials’ must be treated with extreme caution. It is also noteworthy that since 1998, the bTb problem has deteriorated so seriously that herd breakdowns have returned to a level not seen since the 1950’s."
...and still we kill the 'canaries in the coalmine', without listening to the song they sing.
Tuesday, August 15, 2006
Going Dutch. "A 2mm difference..."
A 2 mm difference in swelling, will mean 24 percent of incidents are missed or detected later"
We remarked on this 2mm in our post below 'It Ain't what you do ...", but have now had time to read the whole file. A "small difference in performance", the lady said. Define 'small' in the context of the above passage from the full statement, and redefine 'small' after reading the description of the reactions described in more precise epidemiological terms by her staff at VLA as a "statistically significant difference". And remember - just 2mm.
The Chief Veterinary Officer has issued a report (317 KB) on the recent reduction in the number of new TB incidents in Great Britain. See in particular p. 12 and 14 of the 23 page pdf.
Note: The slaughterhouse cases referred to in the paper are 'Confirmed', and have been added to CNI found at herd tests. The samples submitted by MHS for culture from slaughterhouse examinations of carcasses are up by a not insignificant 35 - 75 percent on last year. (Defra figures Jan - March +75%, Jan -May +50% and Jan - June +35%)
Also, we make the 'herds under restriction from a TB incident to total 4.55 percent, (up slightly on last year) and not 3.5 per cent quoted. Defra are probably using the lower Confirmed Incident figure.
That 2mm figure is also of significance in the new TB 64 Interpretation Chart revised by Defra in February (TB64 & TB64a Revised 02/06) and issued to LVI's conducting bTb intradermal testing, which we also mentioned in the posting below.
The interpretation sheet instructs:
"All skin swellings with an increase of more than 2mm in the thickness of the skin fold must be recorded as positive reactions, as should any swelling irrespective of size, showing oedema .
+ Positive - an increase of more than 2mm in skin thickness or any reaction with oedema.
Veterinary practitioners who have had the oportunity to study the new test interpretation chart, have remarked on a 'marked tightening up' of reactions which may be described as 'oedemous', with the result that even a 0 (zero measurable) rise on the bovine lump, but if showing oedema will classed as an Inconclusive on a standard interpretation, and a Reactor on severe interpretation of the test.
So what have we got here? An annex and graph towards the end of a long pdf file - which bears little relation to the CVO's press statement at the beginning. A new, improved 'Revised Interpretation Chart' issued at the peak of the 'drop' in cases, and coincidentally at the peak of the use of ID Lelystad tuberculin - which is not mentioned at all. And of course the continued mention of that 'small difference in performance' by the lady, which is a rather glib translation of the report's actual description of a "statistically significant difference" between ID Lelystad bovine antigen and the UK product. Of 2mm perhaps? Which when number crunched through Defra's computers arrives at the staggering conclusion, that "a 2mm difference in swelling will mean (not might, or maybe - WILL) 24 per cent of incidents are missed or detected at a later stage". And if the test is a routine one, that 'later stage' will be a year or more.
And as we said in our post below, it may be small to the CVO but that 2mm in a scale of 0-5mm for a Reactor on standard and 0-3mm on severe interpretation, with the extra proviso of 'any oedemous reaction' to be classed as positive even if not measurable, is life or death to some poor cow, and a pass or a fail for the herd - and yet another inconsistant in the convoluted life of the RBCT, the data for which, prior to its ritual torture in the hands of the statisticians, is gleaned from the numbers of herd breakdowns, as determined by the intradermal skin test...
And if we have joined the dots correctly, and we have no reason after reading this report, to think that we have not, the Lelystad bovine tuberculin antigen has missed almost a quarter of bTb cases. This up until February 2006, when the new 'TB64 / revised 02/06' interpretation chart made a belated attempt to tighten up the readings to cope with a 'statistically significant difference" in reaction. In which case, the drop in cases is not a drop in incidence of bTb at all, it is a drop in detection, and that is quite different.
Interesting.
We remarked on this 2mm in our post below 'It Ain't what you do ...", but have now had time to read the whole file. A "small difference in performance", the lady said. Define 'small' in the context of the above passage from the full statement, and redefine 'small' after reading the description of the reactions described in more precise epidemiological terms by her staff at VLA as a "statistically significant difference". And remember - just 2mm.
The Chief Veterinary Officer has issued a report (317 KB) on the recent reduction in the number of new TB incidents in Great Britain. See in particular p. 12 and 14 of the 23 page pdf.
Note: The slaughterhouse cases referred to in the paper are 'Confirmed', and have been added to CNI found at herd tests. The samples submitted by MHS for culture from slaughterhouse examinations of carcasses are up by a not insignificant 35 - 75 percent on last year. (Defra figures Jan - March +75%, Jan -May +50% and Jan - June +35%)
Also, we make the 'herds under restriction from a TB incident to total 4.55 percent, (up slightly on last year) and not 3.5 per cent quoted. Defra are probably using the lower Confirmed Incident figure.
That 2mm figure is also of significance in the new TB 64 Interpretation Chart revised by Defra in February (TB64 & TB64a Revised 02/06) and issued to LVI's conducting bTb intradermal testing, which we also mentioned in the posting below.
The interpretation sheet instructs:
"All skin swellings with an increase of more than 2mm in the thickness of the skin fold must be recorded as positive reactions, as should any swelling irrespective of size, showing oedema .
+ Positive - an increase of more than 2mm in skin thickness or any reaction with oedema.
Veterinary practitioners who have had the oportunity to study the new test interpretation chart, have remarked on a 'marked tightening up' of reactions which may be described as 'oedemous', with the result that even a 0 (zero measurable) rise on the bovine lump, but if showing oedema will classed as an Inconclusive on a standard interpretation, and a Reactor on severe interpretation of the test.
So what have we got here? An annex and graph towards the end of a long pdf file - which bears little relation to the CVO's press statement at the beginning. A new, improved 'Revised Interpretation Chart' issued at the peak of the 'drop' in cases, and coincidentally at the peak of the use of ID Lelystad tuberculin - which is not mentioned at all. And of course the continued mention of that 'small difference in performance' by the lady, which is a rather glib translation of the report's actual description of a "statistically significant difference" between ID Lelystad bovine antigen and the UK product. Of 2mm perhaps? Which when number crunched through Defra's computers arrives at the staggering conclusion, that "a 2mm difference in swelling will mean (not might, or maybe - WILL) 24 per cent of incidents are missed or detected at a later stage". And if the test is a routine one, that 'later stage' will be a year or more.
And as we said in our post below, it may be small to the CVO but that 2mm in a scale of 0-5mm for a Reactor on standard and 0-3mm on severe interpretation, with the extra proviso of 'any oedemous reaction' to be classed as positive even if not measurable, is life or death to some poor cow, and a pass or a fail for the herd - and yet another inconsistant in the convoluted life of the RBCT, the data for which, prior to its ritual torture in the hands of the statisticians, is gleaned from the numbers of herd breakdowns, as determined by the intradermal skin test...
And if we have joined the dots correctly, and we have no reason after reading this report, to think that we have not, the Lelystad bovine tuberculin antigen has missed almost a quarter of bTb cases. This up until February 2006, when the new 'TB64 / revised 02/06' interpretation chart made a belated attempt to tighten up the readings to cope with a 'statistically significant difference" in reaction. In which case, the drop in cases is not a drop in incidence of bTb at all, it is a drop in detection, and that is quite different.
Interesting.
Thursday, August 10, 2006
New Gamma Interferon trial announced.
Defra today announced a new trial using gamma interferon as a back up to the Intradermal skin test from October 2006. Emphasising that the skin test - an internationally recognised diagnostic tool - will still remain the primary test, (even though his CVO implies retraining is necessary to make sure they all do it properly) Ben Bradshaw announced further specific and limited use of gamma interferon as back up.
http://www.defra.gov.uk/animalh/tb/control/gamma.htm
The announcement describes the proposed use of gamma interferon in England and Wales, as follows;
"Under this new policy the g-IFN test will be applied mainly in 3 and 4 yearly testing parishes in an attempt to ensure that infection in such areas does not become established in cattle or wildlife. The test will also continue to be available to use as a disease control tool in TB hotspot areas.
From October 2006 the use of g-IFN test will be mandatory, to enhance sensitivity and detection of infected cases, in the following prescribed circumstances:
*All confirmed new incidents (CNI) in 3 or 4 year parish testing intervals (PTIs), including those that fail to resolve through repeated skin tests or where complete or partial de-population is contemplated .
*Confirmed incidents failing to resolve (with Visible Lesions), despite taking bio-security precautions in 1 and 2 year PTIs, including those herds where a complete or partial de-population is contemplated
*Used at the first Inconclusive Reactor (IR) retest in unresolved IRs in herds in 1 and 2 year PTIs.
Additionally, the test will be used occasionally to enhance specificity in the following limited circumstances:
*Non-specific reactor procedure for unconfirmed breakdowns in 2, 3, or 4 year PTIs
*Suspected fraudulent reactors
More information on these prescribed circumstances is detailed below.
Background
As set out in the Government strategic framework for the sustainable control of bovine tuberculosis (bTB) in Great Britain, the Government will continue to develop a sound scientific evidence base by supporting research to improve our understanding of the disease and generate new tools, particularly in relation to diagnostics and vaccines."
http://www.defra.gov.uk/animalh/tb/control/gamma.htm
The announcement describes the proposed use of gamma interferon in England and Wales, as follows;
"Under this new policy the g-IFN test will be applied mainly in 3 and 4 yearly testing parishes in an attempt to ensure that infection in such areas does not become established in cattle or wildlife. The test will also continue to be available to use as a disease control tool in TB hotspot areas.
From October 2006 the use of g-IFN test will be mandatory, to enhance sensitivity and detection of infected cases, in the following prescribed circumstances:
*All confirmed new incidents (CNI) in 3 or 4 year parish testing intervals (PTIs), including those that fail to resolve through repeated skin tests or where complete or partial de-population is contemplated .
*Confirmed incidents failing to resolve (with Visible Lesions), despite taking bio-security precautions in 1 and 2 year PTIs, including those herds where a complete or partial de-population is contemplated
*Used at the first Inconclusive Reactor (IR) retest in unresolved IRs in herds in 1 and 2 year PTIs.
Additionally, the test will be used occasionally to enhance specificity in the following limited circumstances:
*Non-specific reactor procedure for unconfirmed breakdowns in 2, 3, or 4 year PTIs
*Suspected fraudulent reactors
More information on these prescribed circumstances is detailed below.
Background
As set out in the Government strategic framework for the sustainable control of bovine tuberculosis (bTB) in Great Britain, the Government will continue to develop a sound scientific evidence base by supporting research to improve our understanding of the disease and generate new tools, particularly in relation to diagnostics and vaccines."
It ain't what you do.....
... it's the way that you - or in this case vets doing Tb testing - do it.
So concludes Debbie Reynolds, the Chief Veterinary Officer in a news release today, which targetted veterinary practitioner's 'application' methods of the intradermal tuberculin skin tests as a factor in the drop in cases, rather than the Lelystad tuberculin used in their guns. Well that will make friends and influence people won't it?
http://www.defra.gov.uk/news/2006/060810b.htm
A quote from the report:
"Debby Reynolds, the Chief Veterinary Officer, who was asked by Ben Bradshaw in June to undertake a review of the apparent fall in the number of new TB incidents, has concluded that there has been a real reduction in the number of new TB incidents, but that it is too early to determine whether this is a temporary phenomenon or likely to become a sustained trend. Dr Reynolds has considered whether the switch in tuberculin supply from that manufactured by the Veterinary Laboratories Agency to that purchased from Holland could have caused this reduction. She has concluded that the small difference in performance between the two tuberculins is not significant enough on its own to have had such a significant impact, particularly against the background of the evidence in the DNV Consulting report about the variation in the way the test is carried out. Further analysis will be carried out to try to reduce the level of uncertainty around these conclusions."
Whaaaat? Would that be the ' small difference' which provoked Defra's Feb 2006 re-interpretation chart? The loss of about 2mm of sensitivety / specificity which made a Pass on the old interpretation chart into either an Inconclusive or a Reactor - from February? No mention then of the batch (s) which provoked not a single reaction at all, or was that down to 'testing procedure' as well? And did all those veterinary practioners who now face retraining, have a mental block together, all of them forgetting how to test cattle just after Christmas en masse . Must have been a good party.
And how delicious that the Lelystad tuberculin has been in the country from June 2005, and in use in the RBCT areas during the Krebs' trial, but without the benefit of Defra's new update and 'markedly tighter' (veterinary opinion, not ours) interpretation chart. What will that do to the already tortured data of the Krebs results - all of which rest on the number of cattle breakdowns, as tested and recorded by SVS and LVI personnel, who are now to undergo 'retraining' - and using serum which the CVO herself says 'has a small difference in performance"?
Madame, with the greatest of respect, a 2mm difference in performance is not 'small'. With only 5mm to play with, or under severe interpretation 3mm, as the late Tony Hancock pointed out, "It might only be a small amount to you, but it is the difference between life and death for someone". Or in this case some cattle, and certainly the difference between pass or fail, and a herd breakdown and a clear test.
So concludes Debbie Reynolds, the Chief Veterinary Officer in a news release today, which targetted veterinary practitioner's 'application' methods of the intradermal tuberculin skin tests as a factor in the drop in cases, rather than the Lelystad tuberculin used in their guns. Well that will make friends and influence people won't it?
http://www.defra.gov.uk/news/2006/060810b.htm
A quote from the report:
"Debby Reynolds, the Chief Veterinary Officer, who was asked by Ben Bradshaw in June to undertake a review of the apparent fall in the number of new TB incidents, has concluded that there has been a real reduction in the number of new TB incidents, but that it is too early to determine whether this is a temporary phenomenon or likely to become a sustained trend. Dr Reynolds has considered whether the switch in tuberculin supply from that manufactured by the Veterinary Laboratories Agency to that purchased from Holland could have caused this reduction. She has concluded that the small difference in performance between the two tuberculins is not significant enough on its own to have had such a significant impact, particularly against the background of the evidence in the DNV Consulting report about the variation in the way the test is carried out. Further analysis will be carried out to try to reduce the level of uncertainty around these conclusions."
Whaaaat? Would that be the ' small difference' which provoked Defra's Feb 2006 re-interpretation chart? The loss of about 2mm of sensitivety / specificity which made a Pass on the old interpretation chart into either an Inconclusive or a Reactor - from February? No mention then of the batch (s) which provoked not a single reaction at all, or was that down to 'testing procedure' as well? And did all those veterinary practioners who now face retraining, have a mental block together, all of them forgetting how to test cattle just after Christmas en masse . Must have been a good party.
And how delicious that the Lelystad tuberculin has been in the country from June 2005, and in use in the RBCT areas during the Krebs' trial, but without the benefit of Defra's new update and 'markedly tighter' (veterinary opinion, not ours) interpretation chart. What will that do to the already tortured data of the Krebs results - all of which rest on the number of cattle breakdowns, as tested and recorded by SVS and LVI personnel, who are now to undergo 'retraining' - and using serum which the CVO herself says 'has a small difference in performance"?
Madame, with the greatest of respect, a 2mm difference in performance is not 'small'. With only 5mm to play with, or under severe interpretation 3mm, as the late Tony Hancock pointed out, "It might only be a small amount to you, but it is the difference between life and death for someone". Or in this case some cattle, and certainly the difference between pass or fail, and a herd breakdown and a clear test.
Latest bTb figures
"There has been a substantial reduction in the number of new TB incidents in January - June 2006 compared to the same period in 2005. The provisional statistics presented here indicate that this reduction is 19%, although this figure will reduce as further test results are input by AHDOs. It is too early to draw any conclusions about whether the decrease is a temporary or a more sustained reduction and further analysis is needed to identify the reasons for the fall. However, it is likely to be caused by a complex combination of factors. There is no evidence at the moment that the switch in tuberculin supply has caused this reduction although further analysis is required before this can be confirmed."
See: http://www.defra.gov.uk/animalh/tb/stats/latest.htm
If this paragraph seems familiar, then that is because it has been used in the last three months to express Defra's comments on its monthly bTb statistics, posted on the Defra website. The only difference in wording being the percentage drop: "April : 27%, May: 20% and now June: 19%." but these statistics are are an amalgum of several months, from which it is difficult to see the whole picture. And we would respectfully point out, produced by a department who comfortably airbrushed out almost 50% victims of its FMD culling spree.
So what is the story behind the figures? For sure 'other influences' will have had an effect. But how much? Two blazing hot summers will influence the time that m.bovis survives on cattle grazing ground, but the same dry hot weather will put badgers under stress as the ground is too hard to dig, and natural water supplies short. Any infectious disease has a 'bell curve' of a rise in cases, followed by a drop, and tuberculosis may have peaked in the badger population and be waning. Even farmers may have reached the end of their tethers and with the introduction of tabular valuations, be sorting out their own badger / cattle bio security. But all these factors, would have had to have happened together and at the same time last autumn, for the skin tests (for that is what Defra's statistics are based on) to have shown such a dramatic change early this year. And even this is only half the story.
Further analysis of the past 4 months are interesting. Defra's headline figures are for 'New Herd Incidents'. That is herds at a routine test, which were classed as 'clear' and are going under restriction for the first time. It is these herds which saw the drop of almost 30% in Jan - March, then 27% Jan - April, 20.2% Jan - May and 18.7% currently Jan - June. But what of Defra's other figures?
Cattle slaughtered over the last 4 months are consistantly over 30% less than 2005. (Range 36.6 - currently 33%) That is good news, but slaughterhouse cases, that is cattle found by MHS examination are up by much more than that. Range +75% - +35% currently.
Herds under Tb restriction through a bTb incident (as opposed to overdue test/data) are steady at between 1 - 3% less than last year. So although the new herd incidents are down (or not being found) the herds under restriction figure has barely changed. Jan - March -1%, Jan - April -3,5%, Jan - May - 1.7% and currently to June -1.9%, so they are not being cleared.
But the bad news behind this headline is that herds registered on Vetnet, from which Defra draw their statistics, are down too, so the percentage of herds under bTb restriction is actually UP on 2005. Jan - March 3.65% (up +0.05%) Jan- April 4% (=) Jan - May 4.33% (+0.03%) and currently Jan - June 4.55% (+0.02%)
So, a huge drop in February / March in new herd incidents , while not sustained but is still dramatically less than last year: cattle slaughtered are consistantly down over one third for each of the last 4 months - but slaughterhouse cases up by at least the same amount. The total number of herds under restriction, barely changed while the percentage of these herds, drawn from total registered herds is up. And just to throw a real spanner in the works, in February some AHDO's sent out a 'Revised bTb interpretation chart- TB64 02/06', to their local vets.
This indicates a marked tightening up on interpretation of the skin test, with zero tolerance to any oedema at all in the area jabbed. Below a 2ml rise on skin thickness, even '0' and '1' ml are classed as IR or Reactor, whether or not they matched by an avian rise of the same type. 2ml can be the difference between a Pass and an Inconclusive, or an Inconclusive and a Reactor.
Although we have no grounds on which to base this comment - yet - we suspect that Lelystad tuberculin has given a slightly different reaction from the UK serum, a fact that VLA have only just caught up with. It maybe also strain specific, in that our UK serum identified some or all of the UK strains better. And we also suspect a completely duff batch - for whatever reason - sometime after Christmas which accounted for the precipitous fall in Jan - March. Time will tell.
But as far as International Trade goes, while our herd incidents are at 4.55% of the national herds and rising, we are as far away from Tb free trading as ever.
Sunday, August 06, 2006
Snippets.
As well as the much publicised new 'Advisory Group' which we covered in the post below, this week has seen a few more interesting snippets. As more information comes to hand, we will update.
* We do not propose to cover in any detail the Badger Trust's spokesman's convoluted reasoning with his calculater, that 3000 cattle may enter the food chain with undisclosed bTb. His target appears to be the intradermal skin test, and its alleged accuracy. Suffice to say that parliamentary questions covered this one in spades, with the unequivocal answers that in the abscence of a wildlife reservoir, it was used all over the world as the primary diagnostic tool for bTB under both OIE rules and EU Directive 64/432/EEC , with no problems whatsoever [8/12/2003 Col. 218W 141968] and [30 /01/2004 Col 540W 150492] and [25/03/2004 Col 989W 159061].
Cattle carcasses traded as beef have to undergo both an ante mortem (skin test) and post mortem examination for bTb. So in accusing Defra of allowing infected animals into the food chain, Mr. Lawson is in effect accusing the MHS (Meat hygiene Service) operatives, whose job it is to examine every carcass for signs of disease, of slack practise. Pretty smart.
* We expect Defra to announce a Gamma Interferon trial costing just under £750,000 - but only in areas of 3 or 4 year testing. For large parts of the country, now subject to persistant and pernicious drip feed from wildlfe, it is felt (we are told) that GI is " a complete waste of time". Without action on that wildlife reservoir, everything is a waste of time and money - but let that pass. We could point out however, that for the 3 and 4 year testing regimes Gamma Interferon is still under international trade directives a secondary tool. The intradermal skin test is the primary. But as in other countries, it may speed up diagnosis of animals in the 30-50 day latent period.
*The third snippet, is probably the most important, not that we would expect the voluble Mr. Lawson to agree with our emphasis. More on this as we get it, but this deals with the EU and a 'one size fits all' policy towards cattle testing.
Since the 1950's when a single jab was administered to detect bTB, and heaps of dead cattle indicated that something was amiss, the UK has developed the 'Comparative' intradermal skin test. Our environment is condusive to large flocks of birds, which share pasture with cattle - and carry tb. Avian tb. So the veterinary profession developed our comparitive test. And certainly it is our experience that if cattle are exposed to chicken farming at close contact, or to seagulls, rooks, pheasants or pigeons then the top bumps are very evident. But more importantly, they bring up a bovine bump too.
A Midlands vet, ordering tuberculin for pre movement testing, was recently asked "is this for export cattle?".
When querying why the difference, he was told that cattle for export could only have a single bovine jab. More questions were asked on this, and the answers (verbally at the moment) were that the bulk, if not all of mainland Europe manages with a single jab. And they think the UK should do the same, in fact as we know from the Veterinary certificate covered in our posts Sept. 2004 , http://bovinetb.blogspot.com/2004/09/update-russia-and-tb.html the level of bTB in the UK and Ireland is giving our EU masters serious indigestion. So, a derogation - a year's grace - has been agreed whereby the UK can continue with a compartive skin test, not only for exports, but ALL TESTS. But after that .......
One size fits none? We may have to comply with EU Directives and use a single one - pigeons, pheasants, rooks, seagulls or not.
* We do not propose to cover in any detail the Badger Trust's spokesman's convoluted reasoning with his calculater, that 3000 cattle may enter the food chain with undisclosed bTb. His target appears to be the intradermal skin test, and its alleged accuracy. Suffice to say that parliamentary questions covered this one in spades, with the unequivocal answers that in the abscence of a wildlife reservoir, it was used all over the world as the primary diagnostic tool for bTB under both OIE rules and EU Directive 64/432/EEC , with no problems whatsoever [8/12/2003 Col. 218W 141968] and [30 /01/2004 Col 540W 150492] and [25/03/2004 Col 989W 159061].
Cattle carcasses traded as beef have to undergo both an ante mortem (skin test) and post mortem examination for bTb. So in accusing Defra of allowing infected animals into the food chain, Mr. Lawson is in effect accusing the MHS (Meat hygiene Service) operatives, whose job it is to examine every carcass for signs of disease, of slack practise. Pretty smart.
* We expect Defra to announce a Gamma Interferon trial costing just under £750,000 - but only in areas of 3 or 4 year testing. For large parts of the country, now subject to persistant and pernicious drip feed from wildlfe, it is felt (we are told) that GI is " a complete waste of time". Without action on that wildlife reservoir, everything is a waste of time and money - but let that pass. We could point out however, that for the 3 and 4 year testing regimes Gamma Interferon is still under international trade directives a secondary tool. The intradermal skin test is the primary. But as in other countries, it may speed up diagnosis of animals in the 30-50 day latent period.
*The third snippet, is probably the most important, not that we would expect the voluble Mr. Lawson to agree with our emphasis. More on this as we get it, but this deals with the EU and a 'one size fits all' policy towards cattle testing.
Since the 1950's when a single jab was administered to detect bTB, and heaps of dead cattle indicated that something was amiss, the UK has developed the 'Comparative' intradermal skin test. Our environment is condusive to large flocks of birds, which share pasture with cattle - and carry tb. Avian tb. So the veterinary profession developed our comparitive test. And certainly it is our experience that if cattle are exposed to chicken farming at close contact, or to seagulls, rooks, pheasants or pigeons then the top bumps are very evident. But more importantly, they bring up a bovine bump too.
A Midlands vet, ordering tuberculin for pre movement testing, was recently asked "is this for export cattle?".
When querying why the difference, he was told that cattle for export could only have a single bovine jab. More questions were asked on this, and the answers (verbally at the moment) were that the bulk, if not all of mainland Europe manages with a single jab. And they think the UK should do the same, in fact as we know from the Veterinary certificate covered in our posts Sept. 2004 , http://bovinetb.blogspot.com/2004/09/update-russia-and-tb.html the level of bTB in the UK and Ireland is giving our EU masters serious indigestion. So, a derogation - a year's grace - has been agreed whereby the UK can continue with a compartive skin test, not only for exports, but ALL TESTS. But after that .......
One size fits none? We may have to comply with EU Directives and use a single one - pigeons, pheasants, rooks, seagulls or not.
New Advisory Group - Talking the Talk.
Peter Jinman, a veterinary practioner from Hereford and former president of the BVA (British Veterinary Association) is to head a new advisory group on bTB.
Established by Defra, the group will replace the Tb forum, and will advise ministers and the Chief Veterinary Officer on practical policies to help control the disease. It will also play a leading role in Defra's "engagement with interested organisations". We hear that members of this elite squad will meet Mr. Jinman in small groups, thus leaving him the role of 'referee' in Defra's proposed 'engagement', whose remit includes:
* Working in partnership with Defra to develop Tb control policies in England and providing a practical perspective on delivery.
* Ensuring the views of all interested parties are taken into account in developing Tb control policies, and to help develop a shared understanding on possible control options.
* Acting as a conduit of information between Ministers and the CVO by responding to their requests for advice, and advising on issues of concern to interested organisations.
Defra was keen to point out that members of the group would serve as individuals, as would Mr. Jinman, and would not represent any organisations that they may be associated with. And our own 'little Ben' , Minister for animal health and welfare, Mr. Bradshaw commented that effective control of Tb would only be possible in partnership with farmers, veterinary surgeons, wildlife groups and other interested parties. He welcomed Peter Jinman's role in this.
We wish the group every success. But from Lord Recycled-Rooker's comments on BBC 5 live this week coupled with David Miliband's political expectations and the Badger Trust's scurrilous attempts to kneecap the meat industry, don't expect it soon. We would also take the opportunity to remind readers (and Mr. Jinman ) that control of bTb - a group 3 zoonosis, already spilling into other species - is the responsibility of Defra. Talk of 'partnerships' make are good soundbites. But they are a comfort blanket of prevarication and hot air when it comes to infectious disease control. Defra may be 'talking the talk', but we do not expect them to 'walk the walk' any time soon. And Parliamentary Questions 27/01/2004 Col 246W 150543 tells us that:
" Ministers consider carefully the advice of these bodies in formulating policy. However, there is no requirements for Ministers or the Department to abide by their advice, nor do these bodies have any formal power to veto departmental proposals".
Quite.
Established by Defra, the group will replace the Tb forum, and will advise ministers and the Chief Veterinary Officer on practical policies to help control the disease. It will also play a leading role in Defra's "engagement with interested organisations". We hear that members of this elite squad will meet Mr. Jinman in small groups, thus leaving him the role of 'referee' in Defra's proposed 'engagement', whose remit includes:
* Working in partnership with Defra to develop Tb control policies in England and providing a practical perspective on delivery.
* Ensuring the views of all interested parties are taken into account in developing Tb control policies, and to help develop a shared understanding on possible control options.
* Acting as a conduit of information between Ministers and the CVO by responding to their requests for advice, and advising on issues of concern to interested organisations.
Defra was keen to point out that members of the group would serve as individuals, as would Mr. Jinman, and would not represent any organisations that they may be associated with. And our own 'little Ben' , Minister for animal health and welfare, Mr. Bradshaw commented that effective control of Tb would only be possible in partnership with farmers, veterinary surgeons, wildlife groups and other interested parties. He welcomed Peter Jinman's role in this.
We wish the group every success. But from Lord Recycled-Rooker's comments on BBC 5 live this week coupled with David Miliband's political expectations and the Badger Trust's scurrilous attempts to kneecap the meat industry, don't expect it soon. We would also take the opportunity to remind readers (and Mr. Jinman ) that control of bTb - a group 3 zoonosis, already spilling into other species - is the responsibility of Defra. Talk of 'partnerships' make are good soundbites. But they are a comfort blanket of prevarication and hot air when it comes to infectious disease control. Defra may be 'talking the talk', but we do not expect them to 'walk the walk' any time soon. And Parliamentary Questions 27/01/2004 Col 246W 150543 tells us that:
" Ministers consider carefully the advice of these bodies in formulating policy. However, there is no requirements for Ministers or the Department to abide by their advice, nor do these bodies have any formal power to veto departmental proposals".
Quite.
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