Badgers are completely irrelevant to solving cattle TB - that is the conclusion of local badger expert Martin Hancox. His views have been covered in this blog previously and as regular blog readers will know I have been very involved in the campaigns to stop the badger culls. The evidence is just not there to warrant such culls. Anyhow below is Martin's latest piece - but also today is the day that the Glos Badger Group are helping with Badger Day at the British School (behind Star Anise) from 10am with former MP David Drew - and also Caroline's letter to the Guardian below. Click read more.Pic: campaign in 2006 with me dressed as the badger
Caroline Lucas, Green Party writes: "As a long time campaigner on animal protection issues, I was horrified to read of ministers’ plans for a legalised free-for-all shooting of badgers in our countryside (‘Shooting badgers to be legal under plans for big society cull’, 14 April). The idea that ‘groups of volunteers’ would be given permission to organise their own ‘shooting expeditions’ in a manner akin to bloodsports is obscene and unworkable. Given that the Government has so far failed to respond publicly to the Defra consultation on a badger cull, this proposal also smacks of cowardice and looks suspiciously like policy on the hoof. Even aside from the free shooting proposal, the determination of this Government to introduce culling as a solution to bovine TB is highly misguided. The Independent Scientific Group on Badger TB conducted a randomised cull trial over a 9 year period, at a cost to the taxpayer of £50 million, which destroyed 10,000 badgers. In its final report, the ISG concluded that “badger culling can make no meaningful contribution to cattle TB control in Britain. Indeed, some policies under consideration are likely to make matters worse rather than better”. Eighty percent of bovine TB transmission is thought to be caused by cattle-to-cattle infection. Given that it is a respiratory disease, this high rate can be attributed to the trend towards intensive dairy farming, in which cattle are kept in crowded conditions. Rather than cruel and ineffective mass culling, restrictions on cattle movement and contact between badgers and cattle should be given high priority, in addition to research into vaccination as an effective alternative. With this in mind, ministers should urgently take heed of the concerns raised by the National Wildlife Crime Unit and animal protection organisations about the practical and ethical implications of a free shooting policy – and drop its blind commitment to the cruel and unnecessary culling of a legally protected species."
Now to that report...
WHY PROPOSED WELSH (OR DEFRA) BADGER CULLS ARE COMPLETELY MEANINGLESS - by Martin Hancox
The supreme irony in The Great Badgers and Bovine TB Debate is that after some 40 years, the current "Out of Control" Cattle TB crisis, has sparked urgent demands both via the Welsh and English Cull Consultations for an urgent mass badger cull; BUT no-one can apparently see that the crisis is simply due to an explosion of infectious TB AMONGST the cattle population. Absolutely NOTHING to do with badgers AT ALL !!! And far TOO FEW Welsh badgers to make any difference, NOT a self-maintaining major reservoir of TB; THE TRUE HIDDEN RESERVOIR HAS BEEN CATTLE ALL ALONG!
My website cited as sections 1-6 explains the crisis in GB , but also in Wales via three main topics :-
1. TWO KEY ERRORS , in the last 40 years have been Firstly in assuming that only Visible Lesion VL "Open" cases are infectious .. but cows are sputum-positive /infectious before becoming reactors or VL cases , 20 % in the McIlroy study See Kissing cows 6;2f....
And Secondly, a failure to recognise that IR Inconclusive reactors and Unconfirmed cases are merely early stages .. THEY ARE NOT FALSE POSITIVE, AND DO HAVE TB . The WAG strategy recognises these TBEG findings, EC rules so removal of IRs after 1 retest, and 2 clear tests to derestrict unconfirmed breakdowns. Coupled together SOME 2/3 of TB spread has been UNSEEN/UNDETECTED amongst cattle, below the radar , via this True Hidden reservoir. see 1, iceberg pyramid ... The long held view that the only transmission is from badger to badger to cow is spectacularly WRONG ! And so the many badger TB computer simulation models are daft, since not knowing transmission rates within/between clans or to cattle, the badger TB prevalences are simply FROM cattle spillover. Incidentally, poor Shambo, the Shanda Vale monastry bull was an IR in 2004, a VL reactor in 2007 ; but could have been treated with anti-TB drugs like valuable zoo apes, arabian oryx, etc.
2. CATTLE CONTROLS ALMOST ERADICATED TB IN WALES WITHOUT ANY BADGER CULLS . The textbook Area Eradication scheme from the 1950s shrank cattle TB from countrywide to tiny southwest pockets of intensive dairying (5) of under 1000 sq km. Figures given in "More Detailed overview" (4) , show that by the 1970s in Dyfed this comprised a tiny core of a loose cluster of contiguous breakdowns, plus a random scatter of unknown origin/unconfirmed herds Figure 5. By the early 1980s these latter cases had by MAGIC become "due to badgers" Figure 6 , open circle to closed circles in top to middle maps. All Welsh parishes off the "badger problem" list by 1988, but restarted Dyfed/Gwent 1994/5 and back to more annual tests 1991/5.
However, the idea of a widespread self-maintining major hidden reservoir of badger TB was a complete myth. The 700 herd breakdowns 1972-1996 "Mostly due to badgers" according to MAFF in fact amounted to just 46 TB badgers out of 2363 sampled in Table below. Half in main Dyfed cattle hotspot. But some 72 BRO culls didnt work .. yielding a mere 17 TB badgers out of 591 culled. And BROS for clusters of 3, 3, 4 contiguous herds in Dyfed produced only 1 TB badger out of 41 culled .TB was probably widespread amongst badgers as a spillover from cattle in the 1960s, but died out with 1 last case 1971 in the former Glamorgan hotspot see 1940s map in 5. NB NOT Dyfed back then, Anglesey and Isle of Wight soon went clear, 1 without badgers/1 with ! NB Figure in high dairying in 5, shows BADGER CULLS SAME HOTSPOTS OVER 30 YRS HAD NIL EFFECT, SINCE HIDDEN tb IN NON-REACTOR COWS !!! NB. Many studies have shown very little spread of TB either within/between badger clans .. Krebs p. 48; both the North Nibley /Wiltshire perturbation studies found very few tb badgers per clan ; 4 had just 1, 8 had 2, 2 had 1 ... (Macdonald 2006 & Tutttens 2000 a , b) ... similarly few tb badgers north woodchester cull of 14 with TB out of 85 from 11 clans .. Sussex study likewise .. so badger TB not self-maintaining, merely spillover !
TB didnt reappear in badgers until spillover from reintroduced cattle TB :- 1st Gwent 1988, 1st Clwyd 1989, NONE out of 443 Powys before 1996, but the new hotspot so 25 % with TB in the recent RTA survey . IF the proposed IAPA Teifi/Prescelli Intensive Action Pilot cull of c. 1500 badgers went ahead it would yield 375 with TB , BUT only half a dozen from 300 sq.km which Might be a risk to cattle :- multi-lesion super-excretors, ISG p.77, found just 166 out of 11,000 badgers culled 1998-2005 ! Scarcity of TB badgers See also Krebs maps in 5.
Cattle TB is in 90 -99 % of the time a respiratory lung infection caught via airborne droplets/dust with as few as 1-6 bacilli ; after prolonged contact overwintering in barns and yards. The idea that badger urine with 300,000 bacilli / cc Might pass TB to cows is improbable .. 99 % of pee disappears straight into soil, the residue drying out disinfected by UV in sunlight within days, so unlikely a cow could ingest 3 cc of urine with the minimum dose of c. 1 million bacilli . By contrast a bad TB cow can shed 38 million bacilli / day in faeces. so Old Brock almost bound to catch TB turning over cow pats for grubs and worms .. hence TB starts in the throat submandibular glands, (just like human TB from unpasteurised milk formerly) and is Secondarily a lung case . TB in deer , bovine of more often avian, often too via tonsils/retropharyngeals/mesenterics .. as in "dirty feeding" pigs/wild boar too, and bovine, avian, human TB, dies out when not topped up from cows (like Sussex badger Wilesmith 1986) (5)
TB IN WELSH BADGERS 1972-1996 (MAFF Badger Reports)
Badger source .... Clwyd ....Dyfed ....Glamorgan ....Gwent .... Gwynedd ....Powys
Culls 0/8 15/576 0 2/8 0 0/several 17/591
RTAs 2/85 8/804 1/41 19/306 0/92 0/443 29/1772
___________________
ONLY 46/2363 TOTAL
3. CATTLE CRISIS TB EXPLOSION. Sad to recall the success of only 4-11 / yr breakdowns in Wales in 1980s.. last 3 years over 1000 per year. This rise and dramatic spread Figure 1 (in 4) from 1995 - 2005 -2010 (1/4 of GB ) has been exacerbated by three main factors:-
A. too little testing, 9 million in early 1960s, under 2 million in early 1990s Figure 3. In practice this meant relaxing to 2, 3 or even 4 yearly testing allowing TB to spread undected
and become "endemic" again. Also increased stocking, particulary with bigger herds.
B. Mad Cows, as with TB particularly in longer lived dairy cows, hence worst in Dyfed, Clwyd, Powys ..peaking in 1993 (36,000 culled), so normal export of calves to beef rearer areas, and restocking allowed dramatic rise of unconfirmed breakdowns (85 % of cases) , Figures 3, 7; and SEE Colour maps in Krebs 1-3, with mostly local movements (GVJ, Mitchell).; and with spread to areas TB-free for decades eg Anglesey, the Gower.
NB . DNA evidence clearly verifies this pincer-like clonal expansion of cattle TB ; - a. Dyfed hotspot east to Powys, whilst b. Glos spread west via Hereford/Worcs to Gwent/Powys ....a. spoligotype SBO 140 , VNTR strain 7555 Dyfed, but VNTR 7524 Powys... and b. SBO 263 & 673. See Smith, GVJ p. 57, Krebs 4.
C. Foot and Mouth 2001. Lack of testing with accumulated bad breakdowns caused the jump 2000-2002, Figure 8. Welsh new herds doubled from 150 to 348; cattle removed up 4-fold 986 to 4144. The Figure 8 peak of 30,000 and 2008 peak of 40,000 cattle were due to zero tolerance of overdue tests/ more annual testing . Hance also the further "jump" which occurred in Wales was an accumulated backlog revealed by a return to annual testing in the gap between the expanding Dyfed/Gwent hotspots Figure 1 2005 map.. thus, 2006 to 2008 6000 doubled to 12,000 (4000 to 8000 Dyfed); but also partly because the National Herd Health Check bore fruit, with latterly many breakdowns in new north Wales areas, supposedly TB-free.
The indirect costly consequence of the 2001 FMD Disaster has been a tsunami of cattle TB , with since then some 270,000 cattle removed from c 35,000 new herds ; and Nothing to do with badgers at all. Unsurprisingly, having caught up on the accumulated peak backlog , of 12,000 in 2008 .. Welsh cattle culled dropped to 10,400 and 7,700 in 2009/2010; part of the GB total peaks of 40,000 / 36, 000/ 33,000 respectively ; -- Cattle Controls ARE working without ANY badger culls, just as they did in the 1960s !
Some of the bad breakdowns and enduring chronic TB .. in one case 17 years restriction ..(SEE fast answer via different tests Viewpoint, 2 b) .... in big Pembroke dairy herds ; started during the BSE aftermath :- Stephen James lost over 200 cows since 1993 (Farmers Wkly 12 Feb. 2010) ; a Newcastle Emlyn cluster included 1 which lost all 230 cows 1994 ( the Cwymdolais, Usk Gwent 1994 lost 78, with a farm dog affected .... one TB badger reportedly took refuge in a barn on eviction from its clan, as seen elsewhere in Glos in the 1970s/1980s, spillover from a bad 4 farm outbreak caused 100% in the Jacks Mirey badger clan); others due to the FMD disaster include Pedran lost 200; Cilast lost 531 out of 630; Trioni was so bad, with a case oif udder TB hence spread among batches of calves that depopulation of over 800 cows necessary; Gelli Aur more recent , lost over 300 cows, restocking brought in BVD /IBR , and most revealingly, at the peak a number of emaciated TB badgers were found in fields .. badgers died out locally, BUT TB persisted in the herd due to misdsed non-reactors (Farmers Gdian 21 Jan 2011).
Lastly BUT I hear you say both consultations suggest culls would work in a big enough area, with ring vaccination of badgers to mop up perturbation/edge effects ! ?? WELL, SORRY... this new religious mantra is pure nonsense.
The first sign of a rise in TB allegedly due to badger perturbation ..meeting more cows .. was in the 2003 reactive cull arrest ..BUT , ISG p.109, the non-significant 23.7 % rise was BEFORE the cull even started ie a FMD effect., brought in cattle as shown in Wilts special project report SE 3109, were not same DNA spoligotype as local badgers , and Le Fevre's 2005 update showed accumulated reactive/no cull area breakdowns as both c. 340, ie cull of 311 TB badgers had had NIL EFFECT (table in 4).
The evidence of perturbation in proactive areas .. ISG noted NO effect of culls on unconfirmed breakdowns , p 93, tables p. 96, 101
As to the rise in outside areas of 25 % overall, and a drop of 23 % inside culls (tbbc Table 1) .. IN Fact, as shown in 2nd Table below, the initial 43 % "RISE", was not due to perturbation for 3 reasons : -
1. ISG claim the cull would be seen in reactors within weeks .. but the biological implausibility of this is well noted by Godfray, King, and More (in tbbc); as shown a century ago, Svensson, 13 calves caught TB in a barn becoming reactors by 6 or 12 mnths, so with next test in say 6 mnths, minimum time for any effect to appear 12 -18 mnths ( 1)
2.ISG have not fully taken account of the FMD jump, 8000 to 23,000 reactors Figure 8 in 4; 6 reactive culls were after FMD ; 3 proactives start cull were 2002, and as elegantly show by ISG/Woodroffe, Table below, these had the most reactors and the most spillover TO badgers : D , I , J ...Just as badger TB doubled overall,, PNAS "Cattle risk TO badgers "
NB, Also , F ie. west cornwall the longest on annual testing had least reactors/tb badgers, nothing to do with a sea barrier to badger perturbation !
3. ISG have hence failed to take full account of background TB levels .. no.herds/prevalence, the perturbation rises were non-significant, ie by chance , and the effect of pre-movement testing pushed both outside/inside TB up, NB 38 % outside nearly as bad as start level completely unrelated to badgers, and equalising near zero by 2009.
AND SO, the outside rise was nothing to do with badgers, and in fact the outside cattle controls (in a smaller area ) did better than inside .. a drop from 1st cull to 2007 of 70 % vs 49; likewise from 2008 to 2010 a drop of 48 % vs 29 % , neither anything to do with culling a mere 311 reactive /1204 proactive TB badgers 1515 out of 11,000 TABLES in 4.And so badger culls made no meaningfull contribution to controlling cattle TB ...even if you believe the Perturbation MYTH , the ISG/Jenkins 2010 in tbbc noted a 7.5 yr cull in 150 sq.km, MIGHT only prevent 23.6 breakdowns out of 187 expected .
________________________________________________________________
TABLE of lst culls proactive (ISG)
Triplet A B C D E F G H I J
cattle previous year 57, 70, 62, 187, 34, 14, 23, 36, 154, 215, total 852
TB badgers 8, 13, 4, 102 29, 13, 29, 12, 82, 65, 357
_________________________________________________________________
TABLE AS SHOWN IN IN FIGURE 3 IN TBBC CONSULTATION
1ST CULL 1998-2002 2005 end culls 2007 2008 2009 july 2010
OUTSIDE 43 minus 27 38 minus 2 c. minus 10
INSIDE minus 4 minus 53 minus 24 9 c.minus 20
__________________________________________________________________________________________
In Conclusion a critical reappraisal of the Welsh historical TB problem shows NIL evidence of a major badger reservoir of TB, the True hidden reservoir has been cattle all along, and the explosion in TB has sadly been wholly Amongst CATTLE ..... no Badger Cull or Vaccine strategy will have the slightest relevance to controlling Cattle TB .. and any such proposals are wonderfully insane solutions to a non-existent problem ...political expediency pursued well beyond the point of absurdity!!
__________________________________________________________________________
References
The Great Badgers and Bovine TB Debate (GOOGLE Website):- CITED in text as 1, 2 etc
1 Key Misunderstandings , see figure of Two pyramids, with hidden TB reservoir below sea level in "iceberg"
2 Four Cameos , B Viewpoint, dealing with chronic herds..fast antibody test routine use Irelandf, or PCR on faecal swabs.
3 Simplified Overview
4 More Detailed Overview
5 Selected topics .. hi density dairying , transmission, why culls dont work
6 Appendices 2 f Kissing cows
---------------------------------------------------------------------
GVJ Govmt Vet J 2006, bovine TB special www.gvs.gov.uk Jahans DNA strains p.57; Mitchell local cattle moves p.46
ISG 2007 Final report .... also first cull in Woodroffe 2005 J Ap Ec
Krebs 1997 Bovine tuberculosis in cattle & badgers NB COLOUR MAPS , 1. p. 57 confirmed breakdowns ,2. p. 156-7 unconfirmed breakdowns,3. p 58/91 repeat /contiguous breakdowns, 4. 67 / p.173-4 DNA spoligotypes show spillover cattle to badger !, 5. p.165-8 TB badgers culls/RTAs
MAFF : Badger Reports 1-20 , And Chief Vet Reports
Smith 2003 PNAS , 2006 Nature clonal expansion of DNA strains
tbbc Cull Consultation Google .. New measures to control bovine tuberculosis in badgers Sep.2010
TBEG ,TB Eradication Group :- Developing a bovine TB eradication policy, October 2009 report via DEFRA website .... para 54-62 UNCONFIRMED CASES DO HAVE TB !!
No comments:
Post a Comment