Wednesday, December 13, 2006

"Overall level of disease remains unacceptably high"

This the bland non-statement from defra when explaining this month's bTb statistics, which for a short period are available at:

Defra says:

"When making year on year comparisons of bTB incidence, it is important that these are not made in isolation but in the context of the wider disease picture over a longer timeframe. Whilst bTB incidence in Great Britain has fallen recently, this follows a steady increase over recent years. Furthermore, the overall level of the disease remains unacceptably high."

We are not taking anything in isolation. Nothing at all. We can read stats and also comments from our European masters. We see that Ireland have a handle on their problem and we do not. (see post below on how Ireland have halved Tb incidence and related expenditure)

Defra's latest figures show that this year's upward trend continues with the headline figure of 'New Herd Incidence' down during the period Jan - Oct by just 9 percent, from the dizzy heights of almost 30 percent ..... the figure which gave our minister such a splendid shield in March / April.

Herds under bTb restriction are again up on last year, both in simple numbers (+ 40) and percentages. And the percentage of herds under restriction because of a 'bTb incident' Jan to October was 5.67 percent of herds registered on Vetnet database. (To put that in context, the international bTb 'Tb free trading level' for a country is just 0.02 percent)

Posts have been a little sparse this last month. Apologies for that; your contributing farmers have been testing cattle and guess what?

Yup, three of us are under restriction. Again. Happy Christmas.


Anonymous said...

From Trevor Lawson, Badger Trust

Once again, you are only telling part of the story. The number of herds tested has increased by 18 per cent and the number of cattle tested by 15 per cent. Scientists have advised that the TB testing regime was inadequate, thus failing to detect some infected cattle and herds. It is hardly surprising, therefore, that more testing has found more TB. Taken together, the increase in testing and the continued reduction are a significant improvement.

Meanwhile, can you explain why around 3,000 herds are routinely overdue for their TB test when Defra publishes its regular statistics? This number of overdue herds has remained largely constant following the initial drop when testing resumed in the wake of FMD. Given clear evidence of how readily this disease spreads amongst cattle, why are farmers missing their TB testing dates?

Anonymous said...

From Trevor Lawson, Badger Trust

Incidentally, whilst the number of restricted herds is down by nine per cent, the number of cattle slaughtered as reactors is down by 27 per cent, the number of inconclusives down by 25 per cent and the number of contacts down by 54 per cent.

These figures do give the Badger Trust cause for concern. It seems unlikely that the number of conclusives, inconclusives and contacts would have fallen more rapidly than the number of infected herds overall. Could this be due to the subjective nature of the skin test? Are potentially infected cattle being overlooked now that compensation is not so generous?

Something is clearly not right.

Matthew said...

Telling half a story? Us? Nope, we are not. The link to the figures is there ; make of the apalling numbers what you will.

Define 'scientists'? surely not Bourne?.

For sure cattle tested and herd tests have increased. Good grief man, we had 30 goddam tests in 5 years instead of 5 - and so will every other farmer stuck with a pernicious drip feed of infection from 'a name Defra dare not speak'.
But shouldn't that mean MORE cattle are found,- especially with that little gem, pre movement testing in the tool bag,- not less?

The so called 'improvement'; Tb incidence has been rising since April, and is on track to mirror previous years.

Overdue tests: Some farmers will do their testing prior to winter housing, when cattle are easier to handle in enclosed spaces and may delay to suit the farm's workload. But often it is Defra's paperwork which is 'overdue', i.e not logged onto their system. It is running about three weeks behind the actual test itself, but such herds will flag up as 'overdue'.

One of the site's contributers has tested at the end of one month, read the test in the second month and so his results may flag up 'overdue', when in fact all is OK, or not actually as a reactor was found. Post movement tested too. How about that? And unless a cow has open lung lesions, bTb is not 'readily spread' among cattle -the Irish stomped on that one years ago, by housing reactor cattle with in-contact animals for 6 months and absolutely failing to transmit the disease, and then repeating the exercise for 12 months and failing in two thirds of the cases even then. (costello et al.)

By the way, you still haven't explained how our cattle get Tb when no bought in cattle appear on the farm???

But we digress; with your second comment we would agree, but it is absolutely nothing to do with the tabular valuation and everything to do with the CVO's statement which we explored several months ago. Did you miss it?

While its lengthy executive summary and press release, blamed the vets for not filling in forms correctly, the document contained a stunning snippet re Lelystatd tuberculin antigen. It would appear that while it picks us more (VL) Visible Lesion reactors than the Weybridge product, especially at a later stage of the disease, the downside to this is that in the early stages of disease and detection of Non Visible Lesioned (NVL) reactors, it is less effective.

And we haven't said that, the CVO has - or whoever wrote the statement. Buried in it is this stunning comment:
“... there are subtle differences in performance between the Dutch and Weybridge PPDs (suggesting that the Dutch bovine/avian PPD combination is not as good at detecting infection)”.

The statement then refers back to a previous comment regarding sensitivity of Lelystadt tuberculin thus; “the sensitivity of the combined Dutch bovine/avian PPD is less because of failing to pick up NVLs, … This would result in under-detection of cases, resulting in a transient decline in cases reported, despite there being no true decline in cases”. And the authors of the report lean towards this conclusion.....

So Trevor, what have we really got here? A different product certainly – not a bad product, but different – which Weybridge say is giving a “statistically significant difference” in results, its use resulting in a “transient decline in cases reported, despite there being no true decline in cases”.

This is not a decline in incidence of bTb at all, but a decline in detection of incidence. And that, as we said months ago, is quite different.

But after over twelve months of using Lelystatd tuberculin antigen, those VL reactors, missed as very early NVL's will now at a later stage, and to confuse the issue even more, Weybridge tuberculin antigen is in use again as of early November.

You say 'something is clearly not right'. It is not, and it hasn't been for twelve months. These observations of how Lelystatd was behaving in the field, were flagged up by practising veterinarians as long ago as last autumn 2005. It would appear that the CVO agreed, but chose to massage the reasons and blame her vets.

This summer, the second dry one in a row, has also put tremendous pressure on the badgers. It was a case of migrate or starve and has caused the chaos of peturbation and territorial fighting that the RBCT Krebs' badger dispersal trial did.

This winter's Tb tests are not going to be good news for anyone, and as we said, three of us are under restriction again, with Cornish Matthew expecting to go down at his test in the New Year. He is surrounded by a particularly nasty outbreak. No bought in cattle since 1998, and annual testing. We'll keep you posted - of course.