Wednesday, December 03, 2008

Tightening up

As Wales pioneers a closing of its TB eradication circle, it has wildlife still firmly in the frame. But a tightening up of cattle test interpretation has begun.

After the eradication sweeps of the 50s and 60s, as herds were cleared of reactors and more importantly, remained clear, testing was relaxed to reflect risk. And from annual tests, parishes entered a bureaucratic disease lottery of testing sequence. Depending on the prevalence of cattle reactors, parish and herd testing ranged from every 60 days to once in four years.

Over the last ten years, after badger control in response to outbreaks ceased, the number of reactors has rocketed, meaning the number of parishes hoovered up into annual testing (and thus preMT) has increased dramatically. But test interpretation has not altered - until now. Wales are reducing the number of tests an animal giving an 'inconclusive' result can have. Farmers Guardian has the story.

This is falling into line with European advice. And the previous three 'inconclusive' strikes, having been reduced in England to two, becomes just a single re-test in the Principality who are undertaking an annual sweep of all herd tests.

A comment on the posting below, firmly opining that 'of course cattle give TB to badgers and other mammals', has gained credence with the chatterati (as our partner labels such empty vessels with less than a single collective brain cell between them.) Thus we remind readers of previous expensive and ineffective cattle carnage under Liam Downie in Ireland and William Tait in West Cornwall. And reiterate the minister's reply to PQs about the total success of the Thornbury badger clearance:
"No confirmed cases of tuberculosis in cattle in the area were disclosed by the tuberculin test the the ten year period following the cessation of gassing" [150573]
Why would that be, we asked? Anything else done? Biosecurity? Extra cattle measures? Pre movement testing? Nope. The answer:
" The fundamental difference between the Thornbury area and other areas [] where bovine tuberculosis was a problem, was the systematic removal of badgers from the Thornbury area. No other species was similarly removed. No other contemporaneous change was identified that could have accounted for the reduction in TB incidence within the area" [157949]


Tightening up cattle controls will only work if wildlife reservoirs are addressed simultaneously, and arguably current cattle controls are more than adequate (annual testing and double fenced boundaries), provided the maintenance hosts of tuberculosis are removed.

And if they are not, then no amount of cattle testing or culling will work.
Defra have posted at new figures to August, reinforcing our point.

20 comments:

Anonymous said...

You suggest that "current cattle controls are more than adequate (annual testing and double fenced boundaries)"

What a good idea!

Annual testing and double fenced boundaries for all cattle - that really would make a difference.

Just add to that a total ban on cattle movements outside of each 'ring fence' (except to slaughter) and that should sort the problem.

George said...

Well, it might if cattle movements were actually the problem.

They are not, of course, as anybody actually working with the disease will tell you. Investigations of huge numbers of cattle TB cases show that very few of these are caused by cattle movements.

Matthew said...

Anon 12.01.
Did you read the post?
Did you check the links?
Those of us who are involved with this site were and still are, in the position of being on annual testing with ring fenced farms and in most cases no bought in cattle.
Did it make any difference to our TB status?

No it did not.

As George said, and as William Tait, Liam Downie and your contributers found to our (and the taxpayers') cost, such measures had no effect whatsoever while infectious badgers retained their 'right to roam'.

If you really believe what you wrote, you've not been listening.

Anonymous said...

Silly me! I thought that the scientists who spent ten years researching badger culling to control a cattle disease, and found that badger culling was futile while stricter cattle measures were the answer, might reasonably be said to be 'working with the disease'...

Have you been keeping up with the scientific evidence? Perhaps you should insult people less and listen a bit more.

Anonymous said...

As Lord Rooker of DEFRA said badger culling the way the RBCT was performed "don't work" - it was never meant to!

Krebs wanted all badgers culled in the pro-active areas - what did Bourne give him? A lot less than 100%

Scientifically speaking - badgers gassed in-sett go nowhere. Pure black & white science - no badgers - no Badger TB - couldn't be simpler.

If my cows contracted TB from unmanaged wildlife I'd be more than bloody rude.


Peter Brady
SETT

Anonymous said...

but Peter, do you understand what perturbation is?? You're right that killing all badgers would likely eliminate TB but you can't kill all the badgers in the UK. If you cull a group of them then the ones around the edge would come into the open space that has been left (due to the social group structure and territorial marking). Regardless of whether a whole sett has been taken out or part of one. If the badgers around the edge are infected with TB then they will be spreading it to more cattle because they will be moving further - into the empty space left by the culling! And if you cull the area again, you will be culling some of the ones that have come in from the outside thus depleting badger numbers around the edge causing the same problem (i.e. badgers going into newly badger-free areas and spreading their TB more!). The only way that culling would work would be if you could identify the infected badgers and just kill them - but everywhere of course - so that the badgers left that are moving further are uninfected and hence not spreading anything.

We could hypothesise that if you took out an entire sett then this would leave NO badgers occupying this area of land and therefore badgers in surrounding areas would be even more likely to move into the space left. So gassing/killing an entire sett would not eliminate the problem of perturbation.

Matthew said...

Anon 11.42

See http://bovinetb.blogspot.com/2007/07/peturbation-update.html which we posted after a long comment discussion in July 2007.


Here we discussed 'peturbation' as delivered by Bourne's badger dispersal trial, the lack of it in previous clearnaces, and why. Also why a more measured response could work, using what we know about badger behaviour.

Peturbation is maybe overstated anyway, as badgers are not shy in having a communal bean feast in farmer's buildings as Tim Ropers night vision cameras showed. Three social groups joined an orderly queue at 'badger Macdonalds' for their night time pickings.

A midlands farmer counted over 50 a couple of weeks ago, excavating his maize clamp. By any standards that's a hell of a big 'social group' which on the Harris estimates, comprises 8/10 individuals. (Upgraded from 6/8)

The world did not begin with the Bourne conspiracy in 1997, and neither did it end in 2006. Much work and effective management of what is now an endemically infected reservoir of tuberculous badgers occurred before the start of the RBCT, and further work by some of the ISG has continued, with markedly different results.

Walking away has no effect on disease transmission.

And Peter Brady is quite correct: when farmers have taken the bio-security bit as seriously as some of us have, and still had prolonged breakdowns, losing dozens of home bred, valuable cattle and seeing the knock on effect to the taxpayer and our ability to trade within our businesses, we are entitled to get angry. Very angry.

We still have had no answer to our question re badger vaccinations by the way. Efficacy? Delivery? Support for? Legality?

As we said, just curious.

Anonymous said...

I wrote comment 6 and did not write any of the previous comments, therefore am not involved in the discussion on vaccines.

I saw the perturbation entry in July 2007. Perturbation has nothing to do with territorial scrapping or bite wounding (again, I wonder if it's been understood). And the idea that the infected badgers are more likely to disperse is theoretical. There isn't evidence to support the idea that a second or third cull shortly after the first one would lead to unfected badgers repopulating the area. It would be lovely if it were true.

And I wish you'd stop saying that the further work (jenkins et al) showed different results. No, it added on the extra time period after culling and showed what has happened since culling stopped. It does not contradict what was shown in the ISG report, it tells you what happened afterwards - under the very specific conditions of culling for a number of years and the stopping for a couple.

Matthew said...

Anon (6) 10.40.

It would be helpful if you give yourself an eartag. Helps differentiate between all these Anonymouses / Anonymice / Anonymi?

* There is no discussion on vaccines - at least from the Badger Trust. Deafening silence.. That is our point. Hilary Benn thinks they are a good idea. Gabrielle Edwards indicated lack of efficacy in endemic areas. Senior vets and professors say its a no-no and Geoffrey Cox described it as a 'pipedream'. Nevertheless £20million is on the table.

* Peturbation has everything to do with scrapping and bitewounding. That's what dispersed / peturbed badgers, excluded or separated from their home group do. Which is why it is important to clear out the whole group - as Krebbs proposed [ PQ 150895]
Territories are defended [ 157988] vigourously in some cases and forays into other areas are 'likely to represent an opportunity for the inter-group spread of tuberculosis. [ 157989] After bite wounding, '1,000 organisms (units of TB bacterium) could result in generalised tuberculosis" in a badger. [158003]

*The idea that infected badgers are more likely to disperse is not a theory. It was specifically asked within our PQs. The answer:

"Badgers excreting m.bovis are potential sources of infection for other badgers and cattle. [] Research conducted by CSL has identified differences between badgers excreting M.bovis, and uninfected animals. Badgers excreting M.bovis had larger home ranges and were more likley to visit farm buildings" [ 158375]


Also mentioned in other PQs is the spread of tuberculosis 'through aggressive territorial and mating encounters'. Most lesions were found in the respiratory tract indicating inhalation (within a sett) or generalised tuberculosis from bite wounding - see dose needed above.

* What a continuous cull over several weeks does, is not to allow immediate repopulation with clean badgers. As Rosie Woodroffe explained so delightfully, it has the effect of 'sucking out the infected badgers' from neighbouring groups, thus leaving a relatively clean population to repopulate. The 'clean ring' policy (early 80s) had the same effect. Culling stopped when both badgers and cattle tested clear on pm. Often only a single sett involved. A 7 km ring from a confirmed outbreak, reduced after activists pressure to just 1km.

* Jenkins at al was important for two reasons. Firstly it allowed the results of the badger culling in late 2005, to work through in the results of non-synchronised cattle tests. This can take 221 days from exposure to TB bacteria, and would not have been evident from the cattle results available to Bourne a year earlier.
Secondly, and we have argued this point before, the teams who were doing the 8 nights cage trapping were finally allowed to actually catch badgers only in the last two years of the trial, something their managers have on record that they certainly did not do for the first three years, interspaced with a years' lay off for FMD.

It is also important, if only because our minister of Animal Health, having paid for it, has studiously ignored it.

Anonymous said...

The section starting "Jenkins et al...": this point is wrong, the results in the ISG report went up to one year after the end of culling, thus already including all infections in late 2005 (the results in the ISG final report were produced in mid-2007). Jenkins et al looked at what happened AFTER one year after culling stopped.
Your second point here sounds like you are arguing that the "better" culling in the last two years of the trial is now reflected in the results after culling stopped. This is a big jump and not supported by the data which show a linear trend through the course of the trial, not a sudden jump to different results once the "better" culling started.

Perturbation does NOT have everything to do with scrapping/biting. It is NOT what dispersed the badgers. Very few people seem to understand it (I've even heard others say things like "the badgers ran away because they were frightened of being killed"). PLEASE read Woodroffe et al. Journal of Applied Ecology, 2006, 43, 1-10. There it will explain to you what happened to the badgers in the RBCT and how and why culling disrupted the spatial organisation. It was due to them moving further into unoccupied space (as clearly shown by bait marking).

Anonymous said...

In short – yes I do understand perturbation – indeed I understood it before Krebs referred to it in his 1997 report.

Furthermore I understood it when a scientific research project performed way before Krebs (report) established that not only did it occur but culling (done properly) also reduced the incidence of badger TB in cattle in subsequent years – something that DEFRA scientists, etc have re-discovered but should have known about already. This was the reason why pro-active culling shouldn’t have been stopped by the corrupt Politicians - but what does Pro Bourne know? He who pays the piper calls the tune.

As for gassing setts – do as in Thornbury – cull again – and again – and again – and again – go clean for 10 years. Then start again if necessary!

Best regards

Peter Brady
SETT

Tough on TB & Tough on the Causes of TB

PS

Lord Rooker says that ONE BILLION POUNDS has been spent since 1997 - to no effect

How many helicopters, body protections kits or 'snatch' Land Rover replacements would that have bought for our military?

How many of our soldiers' lives would it have saved?

How many diseased tuberculous badgers are worth the life of one dead British soldier?

Welcome to the real world!

So called badger conservations (agro-terrorists) conserve an over-populated sick species. They (you?) are keen to report the number of increasing Road Traffic kills but ignore the rotting half-live carcasses dragging themselves 'round the countryside and infecting everything else.

Selfish? Surely not!

Anonymous said...

I am most definitely not pro-badger and if culling worked I would be all for it - if it actually improved the situation. I just can't stand the way that things get misreported and skewed on this blog.

Don't you dare try to imply that I am someone who needs to be welcomed to the "real world" of war and soldiers dying. Your assumptions are ignorant. You know nothing about me. If you are happy to throw around such comments and insults then you are not someone worthy of an adult discussion.

Anonymous said...

You know who I am! Who are you? If you are not pro-badger – open your eyes – what’s your interest in this blog? Did you just happen across it?

In the 1980’s when gas was used the number of cattle slaughtered was some 500 per year – by today’s standards – culling worked!

How have we got here – by successive governments pandering to the left-wing loony wind-in-the-willows vegetarian townies? (Have I left out anybody?)

Lord Rooker says the Nation will not pay for culling to take place – but it’s the foolish, irresponsible and corrupt New Labour regime that’s wasted the £1 billion achieving nothing – the 10 years RBCT has taught us absolutely nothing!

………and the disease transmissions route is …….?

Farmers know the solution and are prepared to pay for it themselves – a sure indication that – as New Labour keeps saying – it’s the right thing to do!

Peter Brady
SETT
Tough on TB & Tough on the causes of TB

Matthew said...

To recap of previous policies on TB / badgers would take too long, but suffice to say that from 1982 onwards, MAFF / Defra have had their respective hands tied firmly behind their backs by an intensive, increasingly noisy but misguided clamour.

As has been said (many times) Thornbury worked. For ten years at least it kept cattle clear of TB. It was not alone. Other notable and recorded badger clearances occurred at Steeple Lees in Dorset, Hartland in Devon (and East Offaly in the R of I).

The rest of the UK complied with Badger Panel hoops of proposing a cull under strict conditions, often months after the event, within firstly the Clean ring strategy and after that the Interim strategy.

It was during this time that gassing was replaced with cage traps, and the land available was reduced from 7km down to just 1km. and then only on land cattle had grazed. If setts thought to be responsible for disease in cattle were on neighbouring land, in orchards or arable land they could not be touched.

It was against this background that the RBCT was conceived. But from the start its methodolgy (according to Bourne) had a political steer. Its modelling data reflected this, its managers reported in public, that their efforts to trap badgers during the first 4 years were dire - so why on earth would one wish to repeat it? And of course the moratorium was invoked in 1997 on any other badger control 'to prevent the spread of disease' under section 10 of the Protection of Badgers Act.

Now, the latest Anon. comments appear to share an underlying belief that if badgers are left alone and not 'peturbed' then their inherent disease - tuberculosis - will not spill over into cattle or anything else.

Some appear to subscribe to that holy grail, a hidden reservoir of TB carried by cattle, spread to other cattle and sustained by cattle.

We have pointed out that of the farmers who started this site, most subscribe to the 'no bought in cattle' bio security for many other reasons other than TB. We have also reminded readers of previous cattle-only policies in the past, undertaken with vigour by much larger men than John Bourne, which failed dismally, expensively and were quietly shelved.

In an effort to understand badger behaviour, disease transmission opportunities, habitat, disease prevalence and spoligotypes, it was us who phrased many of the PQs which are logged on the site.

The inevitable conclusion, supported by the Evans Postulates - the 'gold standard in epidemiology - is that in the control of TB, whenc a maintenance reservoir exists in wildlife, cattle controls alone are ineffective. Bio security is a red herring, and a 'super excreter' badger in the latter stages of the disease, excluded by his peers, with wider home ranges, and a desire to inhabit farm buildings, has the potential to bring down half a home bred, closed herd - even one on a farm with road boundaries and no shared cattle neighbours - all on its own.

We speak from (bitter) experience.

So we do not subscibe to the 'leave the badgers alone' mantra. That is not an option. And disease spill over into the many other species which we have reported, will continue, as grossly infected populations of badgers with an infinite supply of food, produce more and more (infected in the sett) cubs and keep the circle going.

That is one reason we are curious about the efficacy / logistics / legality of vaccination - a question to which we have not received a reply.

Anonymous said...

Matthew said: "That is one reason we are curious about the efficacy / logistics / legality of vaccination - a question to which we have not received a reply."

Not surprising at all to anyone who reads the DEFRA website.



"As part of Defra’s commitment to tackling the issue of bovine TB (bTB), we have invested in a significant research programme looking into the development of vaccines for both cattle and badgers. The total investment (since 1998) in vaccine development reached more than £17.8 million by March 2008, with over £5.5 million invested in cattle and badger vaccine research last financial year (2007/08).

On 7 July 2008, the Secretary of State for Environment, Food and Rural Affairs announced a commitment to additional funding over the next 3 years. During this time period, £20 million will be spent on vaccine development to strengthen the prospects of successfully developing a usable vaccine."

from:
http://www.defra.gov.uk/animalh/tb/vaccination/index.htm

Ear tag number 007

Anonymous said...

Matthew said: "So we do not subscibe to the 'leave the badgers alone' mantra. That is not an option. And disease spill over into the many other species which we have reported, will continue, as grossly infected populations of badgers with an infinite supply of food, produce more and more (infected in the sett) cubs and keep the circle going."

So your theory is that badgers infect deer and all other species that get bovine TB?

Remove all badgers and bovine TB would disappear - is that what you believe?

Ear tag 10789145

Matthew said...

Anon 007.

Yes we know Defra are starting to hurl money at vaccination. That is no indication of its efficacy, particularly when appled to an endemically infected population. And it is to that question, we have heard a deafening silence.

Anon 10789145.

The removal of badgers from an endemically infected area, followed by a long period of no reactor cattle is not a theory. It is well documented fact.

The spillover from infectious badgers will inevitably reach more mammals than tested sentinel cattle, as population density increases, and with it the proportion of infectious individuals.. Tested cattle react to exposure to m.bovis, which is different from full blown disease, thus most 'reactors' are shot way ahead of becoming infectious.

But no, we would not suscribe to scorched earth (no badgers) under any circumstances. It is neither possible, necessary, nor acceptable.

A management strategy which reduces the number of grossly infected setts / groups, is. And it would be helpful for the UK to catch up with the rest of the world and use PCR to identify such groups from infected environmental material.

Like the tags.

George said...

When asked about cattle vaccination, MAFF said that a TB vaccine was 6 or 7 years away. That was around 1980. Sadly, the answer to this question is still the same. Now in the meantime a lot of research has been carried out and the probability of a usable cattle vaccine is now much higher. There is no guarantee of this, though, and we will have to wait and see. The problem will not go away by itself, unfortunately, and action is needed quickly.

Anonymous said...

Has there been any research on endemic tuberculosis in badgers, badger population explosion, cattle infection, disease spread and an estimation of ‘the tipping point’ where the disease goes vertical graphically speaking?

Peter Brady

SETT

Matthew said...

Peter, the questions asked of governments may not be 'suggestive' 'abusive' or anything that prejudges the answer, so limited and we are not aware of any research which may give the answer Defra doesn't want to hear.

We had to carefully stitch the fabric of this debacle together from its disparate pieces.
We asked about the disease transmission opportunities and epidemiology of tuberculosis in badgers and were astonished at the depth of knowledge. The core question was answered "Tuberculosis is endemic in the UK badger population".

The actual numbers of badgers is fudged. A survey done by members of the Mammal Society found a 77% increase within a decade, and it is reasonable to assume that with an infinite supply of food, particularly in autumn (from cattle sheds, late harvested crops etc. - more cubs survive) that breeding 'success' has continued.
Steve Harris re-hashed his estimate of social group numbers over that time as well, from 6/8 per sett, up to 8/10 individuals. But nobody really knows. Figures quoted are decades out of date.

The linear graph of TB incidence via tested cattle has increased, slowly from a very low point in the mid 1980s, but particularly since 1997. There was a dip in 2005/06 (change of tuberculin antigen) and a rise again now as the Weybridge product picks up its casualties at a later stage of the disease cycle than Lelystadt. But the trend line on a TB incidence graph is up, up and up.

Defra are on record as predicting a 20% year on year increase in herd breakdowns, "in the absence of any new dynamics", but figures to September show over 25% with the number of reactors per breakdown up substantially, and cattle slaughtered up 52% on last year.

Numbers of camelids (many with no cattle contact) goats (no cattle contact), cats (suburban)dogs and 'domestic' pigs are now stacking up together with documented cases (and a death) of m.bovis typed back to the spoligotype circulating in the 'environment' in human beings.