SUMMARY AND CONCLUSIONS regarding The Great Badger TB Debate

This section brings together the far flung pieces of the jigsaw lost amongst a "sea of red herrings" encompassing myths, dogma, false facts, pseudoscientific "theories", as discussed elsewhere, with the help of 8 Key Figures; And tackles two main issues:-

A. Why badgers are irrelevant to solving the cattle TB crisis;

B. How badgers became the focus of attention, How the crisis arose, and How to solve it.

Progress in science and politics happens by serendipity often-times … and the current Cattle Crisis is SO Bad, 4 times worse than in 1960s, that Clearly policies based of current wisdom of the badger/cattle "Problem" have gone badly wrong, and a Radical Rethink of all assumptions is essential ... accordingly;

NB. THE SINGLE MOST IMPORTANT DEVELOPMENT IN THE WHOLE BADGERS AND TB DEBATE OVER THE LAST 40 YEARS IS THE TBEG REPORT ACKNOWLEDGEMENT THAT ALL UNCONFIRMED CASES DO HAVE TB ... ie .The Huge Hidden TB Reservoir, BUT Cows not Badgers!! (43, Just Google it !)...Thus:

The whole virtual reality badger TB debate comes down to a case of mistaken identity ... as shown in the badger/cattle TB cycle diagram in Introduction, rather surreally, it is still being claimed in GB and Eire, that cattle are unimportant in spreading TB to either other cattle or badgers (12,36), and YET the current TB Crisis exploding from the 1979 low point of 89 herds and 600 reactors in tiny southwest hotspots to 5000 herds and 40,000 reactors in an area a quarter the size of GB (Figure 1) in 2008 ... on common sense grounds CAN ONLY be by spread amongst the cattle population (with spillover TO badgers subsequently). Thus, the truth of the matter is that TB has been spreading mostly "below the radar" or below sea level in Section 2 "Iceberg" ... all along ... so as regards the hidden reservoir fuelling the crisis, think cattle instead of badgers, its That Simple!

To recapitulate, a Birds Eye view of the Debate encompasses Sections 1 to 8 of this website; including :-

l. Introduction, with Key Recommendations re: Policy ... With Quo Vadis at end this section, and end comment Policy loopholes at end this Overview.

2. Three Key Misunderstandings

3. Four cameo snapshots, including
A. Open letter Mammal Society and Footnote Prospects for 2010
B. Viewpoint of chronic herd resolution and Footnote 2009 ICMB5 new ideas
C. EFRA Committee and Nov '06 maps, Footnote on badger cull Perturbation
D. Sherlock Holmes sheds light, a three pipe problem

4. Simplified overview of historical textbook Area Eradication Scheme

5. (this section)

6. Selected topics include

1). High density cows or badgers?
2). Culls work or make things worse
3). assorted letters
4) How badgers got the blame … TBEG Report is single most important news in 40 years (seismic shift)
5) Transmission

7. References 1) My main and minor papers ...
2) General useful refs.

8. Appendices 1 & 2 assorted letters etc
3 EFRA Committee contributions...esp. last 3.

Return to top

A. DEATH OF THE GREAT BADGERS AND BOVINE TB DEBATE:- April 1971 -October 2009:- R.I.P!!??

Alas, rumours of this demise have been greatly exaggerated (indeed overlooked altogether !), and will be largely ignored, EVEN Though the following 6 points collectively present an UNAnswerable and IRREfutable case for badger innocence. The rationale behind badger culling is that they are the MAIN infectIOUS TB reservoir being the cause of cattle TB herd breakdowns. However this claim is based on the supposed absence of an infectIOUS cattle source, rather than any clear cut evidence badgers CAN actually give cattle TB:- THE ONLY irrefutable case in 40 years being a very artificial yard experiment (Little 1982 a).(Section 6 (5)). The flaws in this whole debate have amazingly been overlooked for decades, and are very simple : -

l. TOO FEW TB BADGERS

Amazingly no-one over decades of tendentious "debate" has thought to check that there were enough TB badgers to be this Main reservoir, but consistently there have been far too few for this to be true! Thus:-

A. MAFF figures 1972-1996 found just 4608 TB badgers out of 42,130 sampled (3542 /19098 culls, 1066/23032 RTAs or from public). Most of these in the 4 worst cattle TB southwest counties, Avon-Glos Table 1 below; and 92% (977) of the RTAs were in the 8 worst cattle TB counties (including Herefd/Worcs), the remaining 89 being spread widely:- Sussex 34, Staffs 10, Derby & Powys since FMD, an old Glamorgan case c 1971 (9), hence some 27 counties so far with TB badgers overall.

SO, remarkably there have been some 55,000 badgers culled over 35 years, in exactly the same very localised hotspots 1975-2005 with no effect in reducing cattle TB, nor in stopping the inexorable rise since mid-1980s … Simply because they’ve been targeting the wrong victim:- intensive dairying the True hidden reservoir as shown maps Section 6(1), and Figure 5 (Lands End, Dyfed). Alas, we've been here before ... badgers nearly wiped out in many EU countries until it was realised the true vector of rabies in the spread was red foxes...and a vaccine workable since transmission by direct bite contact.

There have been well over 75,000 badgers culled in Eire with no demonstrable effect either, indeed DAF'S Liam Downey famously told the first ICMB Dublin Conference 1991, "Of course we've know for years that badger culls don’t work "... David Coffey's political expediency pursued to the point of absurdity!

B. The above culls did not include some 25,000 gassed underground in c. 4000 setts.

The Krebs/RBCT cull found just 1515 with TB in 11,000 culled from 2000 sq.km.. (SEE Table below)

The Irish culls found just 141 out of 600 sq.km. Offaly; and 286 from 960 sq.km. Four areas, but a MERE 37 from Donegal which had the biggest "cull effect" of 96%, which in fact was via a flare up among contiguous "reference" herds (33, not badgers after all). NB the Four areas cull of 2360 badgers produced 450 with TB:- Cork ,Donegal, Kilkenny Monaghan 212, 48, 77, 113 ... but 210 were NVL unlikely to be infectious, and a proportion were from the buffer areas as well ie couldn’t affect cattle TB in trial area, so "adjusted" down there were just c. 115, 37, 59, 75; ERAD 2003, and 49). (see 2 *)

2. TOO FEW InfectIOUS BADGERS, which might pose a risk to cattle or other badgers.

Only "superexcretors" shedding from multiple lesions likely to be an infectious risk to either cattle or other badgers (see clinical studies 3b, c; 37a; 46d). There were a MERE 166 out of 11,000 badgers culled IN ISG trial p.77 (49). And at Woodchester, with some 350 badgers in 9 sq.km, over 14 year there were only 188 TB badgers, of which a mere 17 superexcretors, or 1 a year (Smith) ... SO no wonder the CSL study found little evidence of TB spread either within clans, or between clans unless a TB badger switched clan. **NB Also, the latest studies of badger TB found very few bite wounds with TB, so not 18% of spread as claimed, and most badgers have early NVL TB, are not infectious ... and everyone assuming "lung infection " means 82% by respiratory spread, but in fact even a thigh injection produces lung TB, the majority of badger TB is dietary "scrofula" caught FROM cows see bottom picture and Section 6(5) (49).

3.TRANSMISSION (Section 6(5))

Again surprisingly ... most folk have just assumed badgers CAN give cows TB, since Supposedly it isn’t from cows;BUT HOW ?

Cattle TB, like human "Consumption", is a respiratory lung disease, which in 90 if not 99% of cases most of the time is caught from other cows (SEE Section 6(5), and NB finding lesions in neck/retropharyngeal nodes in c 1/3 of cows may simply be secondarily via coughed up/swallowed phlegm!, as in man 11a, b). AND Just as you’re unlikely to catch a cold from a passing stranger in the street, sharing an office for a few hours with anyone with a bad dose of sneezing/coughing flu pretty much guarantees you'll succumb too ... so several months of prolonged contact is ideal for spread amongst cattle over-wintering in yards or barns , so not from brief badger visits .

Human TB acquired from unpasteurised milk was common until the 1930s in GB (several thousand deaths a year (25)) ... with swollen neck glands "Scrofula" ; and sadly still prevalent in less developed countries including Mexico (20). Cattle might theoretically get scrofula from badger faeces or urine , but not from inquisitive nosing of TB badger carcases in the absence of the open suppurating skin lesions in N Zealand possums ... may shed 5 billion bacill/gm of pus !(20). Very few TB badgers produce TB faeces, 12 if not all 13 cases in 541 samples came from one terminally sick badger (3b, c; 19) and cattle avoid smelly faeces and cow pats anyway (Hence the scatter of tufts of longer greener grass in recently vacated grazing fields!).

Few badgers produce infectious urine (26 a, 49), and whilst one 30cc urination might contain 9 million bacilli, 99% of that drains straight into the soil, the other 1% is disinfected within 3 days by UV in sunlight, so a cow is highly unlikely to "drink" the requisite minimum dose of 1 million bacilli in 3cc of urine at 300,000 bacilli/cc.

Badger TB however is frequently a dietary scrofula acquired FROM cattle via eating cow pat fauna, with throat lymph nodes entry site (submandibulars); so FROM cattle, NOT from other badgers after all. Chris Cheeseman found little evidence of within-clan spread even when a known lung "hoocher" was present (map of clans in Krebs p.49). The most probable route for this would be by sows weaning cubs on regurgitated food ... evidence may be in cub Y24 shedding bacilli in urine, without any other obvious TB signs , just as in human vaccine bacilli excreted in trials in cattle (37 b) ... if the mum was Y12 riddled with TB but not lactating (3b). It is worth remembering the very "1st" wild TB badgers in the 1950s in Switzerland caught it by EATing infected roe deer carrion! TB has been found in most big cats in zoos because they’re fed on cheap condemned meat too, whereas hounds in hunt kennels get cooked fallen stock so killing any "bugs".

Badger TO cattle transmission under field conditions is wildly improbable!!

Return to top

4. PATTERNS OF badger/cattle TB.

A. Badgers with TB ought to be widespread universally in TB hotspot areas , but in fact occur in very widely scattered (Fig.7) incredibly small micro-pockets ie spillover FROM latest herd TB breakdown(as shown by clean ring culls) (Appdx 3e map).

B.The true high-density reservoir has been intensive dairying all along, not badgers (Section 6(1)) & Fig 5 Penwith/Redruth))

C. Waning/Waxing epidemiological patterns ...
As cattle TB shrank rapidly from countrywide to tiny southwest hotspots (Section 4), it seems as though badger TB died out since not topped up from cattle, and there was no evidence that badgers left behind caused any recrudescence in cattle , particularly as regards the West Penwith intractable area of Lands End cleared in the mid-1980s.(39). NB Badger TB is NOT after all endemic and self-maintaining ... although it may remain for years in one affected badger resident.

Similarly, as cattle hotspots spread inexorably outwards from residual southwest areas into areas TB-free for 50 years there were few or no TB badgers present until introduced by cattle, then spillover to Brock (see Phase D below ) onwards from the 1993 peak in Mad Cows; - Exmoor, Hereford/Worcs, Derby/Staffs, Shropshire/Cheshire. ( Detail Phase D Sketches below)

5. CULLS

A. work or make things worse by perturbation SEE Section 3C & 2, 45

B. are unnecessary. The computer models of Kao, 24; and Cox (in ISG pp.5, 147) suggest cattle controls alone could eradicate TB ... without the supposed essential wildlife element (7, Wilsmore). Whereas in Fact, everyone has forgotten (See Section 4) Scotland and the north; and most of Wales went clear without any badger culls , likewise both the Isle of Wight with badgers and Anglesey without ('tho new immigrants recently over the bridge). Ulster came very close to eradication without any culls, down to 174 reactors in 1971 but premature return to 3 year testing allowed upswing (see Appendix 3e Table ).

6. UNWORKABLE

Back during the low point in the 1970s with tiny remnant hotspots of c. 1500 sq.km. culls were practicable but the cattle crisis is now so bad it is worse than at the start of the scheme in the 1950s, and with an area roughly a quarter the size of GB (Figure 1 ) ... NO Badger Cull OR Vaccine strategy can be remotely workable, practical, or cost-effective in this huge area. And in any case since foot and mouth 2001 with 240,000 reactors amongst some 30,000 new herds swirling around amongst the cattle population ... The True hidden reservoir of TB has been the 60% amongst these of UNConfirmed cases c. 145,000 cattle cases, this contrasts with the TINY number of TB badgers present ... in nearly half the widespread (proactive) RBCT culls there were Just 15 or fewer TB badgers per 100 sq.k.(Table below ) ... so these would be TOTALLY irrelevant and unfindable !! It is either disingenuous or frankly plain daft for DEFRA, Welsh Assembly, and politicians to push for Welsh culls in a mere 288 sq.km, or English injectable badger vaccines in a mere 6 x 100 sq.km (ie in a mere 900 sq.km. out of 1/4 of GB) … when plain common sense suggests these politically necessary "Strategies" CANNOT MAKE THE SLIGHTEST DIFFERENCE to the overall crisis ... ALAS culls/vaccine trials WILL proceed politically, particularly if the EC committee recommend it in 2010, with grant money conditional ... (see Section 3 (a) footnote prospects 2010).

QUO VADIS ... Although it is widely believed that cattle TB is still getting worse, (eg Prof. David King ex-Chief Scientist in Farmers Guardian 22 Jan 2010 and on Radio 4; Guardian letters 19, 21, 25th Jan 2010); the final figures for 2009 may in fact be a few thousand reactors less than the 2008 peak of 40,000. Indeed, re-examining the ISGs data ... whilst post-FMD intensive prioritising of ANNUAL testing of cattle within the 10 ISG proactive areas reduced cattle TB by 23% by 2005, in the 2 years after that it dropped 54%, and in areas outside proactive areas it fell by 23% as these too had more rigorous testing (NB NOTHING to do with the cull badger cull, despite the ISGs interpretation, Jenkins (PDF available and further paper in press) (NB The RISE in reactive areas happened before the cull, so was just part of the FMD upswing nationally, it showed a blip up initially in proactive areas too ISG, 21 b; and in the final analysis there were RISES both inside and outside NO CULL areas (no perturbed badgers) likewise part of the FMD rise pp.88, 94, 97, 100 ... it is a tragedy that "The Great Perturbation Myth" has become so firmly established (2, 45; and Section 3C footnote); BUT it is remarkable how fast intensive rigorously enforced Annual testing can drop TB LEVELS:-

GB 16,000 to under 1000 reactors in just over a decade Section 4
Offaly 360 to 20 in 8 years Appendix 3c ... part of the ERAD intensive cattle trial
Michigan 6000 to 130 reactors in 7 years Appendix 3e
Northern Ireland halved since 2002 without any badger culls.
Inevitably, playing catch-up adding the whole of Wales and southwest England (Figure 1) this year to annual testing will add in several years accumulated CATTLE spread into new breakdowns in the interim, (as happened Nov.2006, See Section 3 C maps; also in the Welsh National Herd Check to end 2009 found 95 extra herds, some 1000 reactors) ... so the 2010 figure will probably be 50 - 60,000 reactors, with renewed outcry illogically demanding a mass BADGER cull. And sadly neither pre-movement testing, nor the TBEG 2 year testing "FIREBREAK" (TOO Narrow at 10 km wide see Annex E in 7 a), will prevent TB from spreading to non-southwest areas, as already seen in 1990s Figure 7 below, including already Leics/Yorks ... with new spillovers to badgers (no TB badgers there so far despite sample to 1996, of 576 and 91 respectively). The whole of England may eventually, like Wales, have to go back to intensive annual testing as in the 1960s when the whole national herd of 9 million cattle were tested yearly (See Appendix 3e, Map 4 and Table 1).

CHRONIC Herds despite repeated attempts to point out that big dairy herds under restriction even 10-15 years Must have a non-reactor active spreader case hidden there ... no-one seems interested in the simple/fast trial of either antibody tests as used in Eire routinely (5), or a PCR on faecal swabs SEE Viewpoint Section 3B farmers/vets of course assume its Brock again!

Return to top

TABLE 1 OF TB LEVELS IN BADGERS BY COUNTY** (From MAFF Badger Report 20, 1997)

INCLUDES SUMMARY FIGURES OF BADGERS WITH TB FROM CULLS 1974-1996, AND BADGERS FROM PUBLIC (RTAs etc) 1972-1996

NB The top 4 counties correspond to the worst south-west CATTLE TB ie. S0-called "Badger Hotspot Parishes" ... with the most Spillover from cattle to badgers. The last 3 counties are outside the core "Badger TB Problem" southwest ... where early on seeming persistent Cattle TB sparked detailed studies SEE Respectively, Little 1982 B//Cheeseman 1985 & Hewson 1987 //Wilesmith 1986... with remarkably few TB badgers from either culls or RTAs so NO Vast hidden badger reservoir. But in the 3 counties apart from the top 4, there were just 110 TB badgers out of 4049 sampled

B. WHY BLAME BADGERS ... WHY THE CATTLE TB CRISIS AND HOW TO SOLVE IT??

Oh what a tangled web we weave when first we practise to deceive . There are three main obstacles to unravelling the "Highly complex and Emotive issue" of badgers and TB.

1. A whole generation of farmers, vets and badger scientists have grown up being told badgers are THE problem, and have forgotten how TB works in cows .Hence believe the only point in testing cattle is to find the sentinel cases hinting at a badger TB pocket ... cull that, problem solved (12)!

2. Everyone has forgotten why badgers came to be blamed 40 years ago.

3. A flood of peer reviewed "scientific "papers based on these flawed assumptions have established some myths set in stone eg. a couple of dozen computer simulation models start with the basic assumption that transmission is Only badger to cattle ... spectacularly wrong ... the post FMD crisis doubled cattle TB initially hence twice the spillover TO badgers (47) ... AND Very sadly everyone is totally hooked on the elegant but spectacularly silly "culls cause Perturbation increases in badgers and cows" ... the ISG failed to grasp the basics of annual testing impacts as in Quo Vadis above ... plus cattle TB basics next section Figures 2 & 3.

THIS SECTION Attempts to rectify this muddled thinking via 4 Parts:

Part 1. Figures 2 & 3 the progression of the disease
Part 2. Figure 4 the 5 historical phases A - E (as in Section 4 also)
Part 3. Figures 5 & 6 getting the blame
Part 4. Figures 7 & 8 the unfolding crisis

Return to top

PART 1. THE PROGRESSION OF THE DISEASE

Amazingly it has seemingly never been spelt out in simple terms the basics of how TB works in cows and hence the basis for any TB eradication scheme (as embodied in EC 64/432). Yet there is Nothing New under the face of the sun ... since there was a very clear understanding a century ago, just after Koch discovered the "tubercle" bacillus in 1882, in the new germ theory, as to the 3 key elements ( to be RE-discovered now !)viz :-

Latency Bang 1899, M'Fadyean 1899 may be latent for many years (as in man);
Test Inadequacy Bang 1892 early and late TB non-reactors, and "no lesion" reactors (ie NVL/ Unconfirmed) cases quotes at head Section 2, 11 A,B;
InfectiOUS M'Fadyean 1888 without lesions but still excreting (37b), hence Richards 1972 "cattle may be infective at any stage during the course of the disease".

As outlined n Sections 2 and 4, cattle TB s a progressive lung infection, a "Consumption" or broncho-pneumonia. As shown in Fig.2 failure of the immune system to control the proliferation of bacilli is evidenced by an increase in the number and size of "tubercle" lesions. This reflects in 3 key elements of the progression in becoming :-

A. reactors, most so early on are Unconfirmed with No Visible Lesions NVL, or M.bovis on culture

B. Confirmed reactors which are VL with M.bovis

C. more infectiOUS with VL LESIONS AS Active Spreader cases.

It is useful to think of this as a "manufactory" production line, with four stages "Rising to the surface"; such that:

Stage Test Lesions** Unconfirmed/confirmed
LT Late TV VL Antibody or PCR on faeces (Section 3B) 5 Only confirmed by accident at abbatoir
MT Middle TB VL Skin test increasingly positive Confirmed
ET Early TB NVL IFN and maybe IR Unconfirmed or weak skin (may revert to non-reactor).
VET Very Early TB NVL Missed altogether

**NB Abbatoir inspection with fast through-put is adequate to find and condemn wholly or in part gross lesion cases, but it misses maybe 1/2 "VL" cases which would have been found by more diligent examination: 1-2 pea size lesions in the large chest volume of a cow ; needles in haystacks, Jubb

And so the reservoir of cattle TB can be thought of as in Section 2, as an iceberg, with VET & ET cases a hidden reservoir below sea level, and circulating freely within the cattle population BELOW THE RADAR. It is CRITICALLY Important to continuing the metaphor to realise that as the early (VET, etc) cases progress and come "On Stream", they rise to the surface above sea level, either in their home or a new herd, so that "new" incidents (actually the tail-end on an ongoing one) appear/reappear out of nowhere; ie Due to badgers again!. This includes notably those herds which went clear after 1-2 retests over-wintering indoors, and hence at spring turn out get the evil eye in encounters with those terrible badgers at pasture - and suddenly are riddled with TB by the next summer/autumn check test (12, 26 b).

Timing//lags are the critical factors in eradication schemes since on the one hand it takes about a year to reach the more infectious MT or LT stages; so annual testing is vital in high prevalence, active TB areas; but on the other hand this arrests the progression at the ET (or VET) stages, so some 60% of new herds and reactors are found so early that they are Unconfirmed, suppressed below the radar (18f).This varies according to the stage of the scheme, or the level of TB in the population targeted; Figure 3, unconfirmed ranged from only 36% in worst areas during FMD - 85% unconfirmed after BSE peaked in 1993 (36,000 cases), with much restocking ... hence spread outwards Figure 7 (where the 90% "due to badgers" arose in 1990s (12)).

This DUAL problem of Infectious VS Unconfirmed cases lies at the very heart of the two key misunderstandings in the whole badger TB debate, since it underpins the basic assumption that cattle-to-cattle transmission is UNImportant, in GB, Eire, Ulster (12,36)! Thus, 2 very widely held beliefs have been that, firstly:-

A). Only "OPEN"/VL cases are infectious ... 2% of cases, Gallagher in Zuckerman pp.86, 94, and 2009; Dunnet para.60; Hewson . Doubly Wrong ... in human TB" closed" lesions may develop so the patient becoming non-infectious; but the key difference is that in cattle lesions REMAIN OPEN and progressive throughout, so even cases with slight lesions remaining in the herd will spread TB more or less rapidly through the herd (Francis a,b); also, if numerous reactors are present at the disclosing test OR "Open"/Lesioned cases remain in the herd the rate of spread may be faster than reactor removals (Blood) ... It is often assumed cattle "become infectious" by 6 months (10,15), but in fact the percentage of cases reaching that stage may be 9% by 6months, 17% by 12months, 26% by 18months, and 34% by 24 months (14 b). Hence annual testing is optimal to catch cases before within-herd spread can occur:- Single(ton) breakdowns in nearly half the low point breakdowns in GB, Eire, Ulster, and only 2-4 reactors in studies as far afield as GB, Argentina, Holland (10, 34, 46b). Six months testing as currently in Wales and tried in Cornwall (39) is too short ... still have to await progression to come "on stream" ... 18 months too long, TB gets embedded in herds ... notably hence in 2 year test areas as explained later!

Hence the cause underlying the distinction in Eire and elsewhere of Minor breakdowns cleared with 1-2 retests; and Major breakdowns where TB becomes established in the herd (10, 36); latent early TB cases are still present at derestriction in some 10% of herds (4), so recurrence at later tests being a major problem. Severity of breakdown and herd size determine likelihood of recrudescence (33b):- herds of 100 or over 200 cattle have a 7 or 14% likelihood of reoccurrence (15).... IFN trials found repeat breakdowns in up to 31% of herds after 14 months (ISG p.239), unsurprising since skin re-tests only 65% accurate thereby missing a third of hidden cases. Latent cases may take 6-7 years to "rise" to the surface (Good, Goodchild, Hewson, Zuckerman p.76). YET again Old Brock's fault! Since the skin test is only 80% accurate 2 in 10 or potentially 200 in 1000 cases may be missed ...

So, big dairy herds with chronic TB under restriction 10-15 years may never go clear ... back in the 1970s when a big herd was 47 cows routine depopulation was normal if 1/2 or even 1/4 of the herd affected ... frighteningly most herds are now 150 with followers, and herds of 200, 500, 1000 aren’t uncommon (15).

ALSO, it is important to understand that much airborne transmission may well be occurring "Below the Radar". Cattle which are borderline NVL/VL May yet be sputum positive in 20% of cases (29, 32), and so many spreaders may wrongly be discounted as sources as NVL, and probably wouldn’t show as sputum positive (minimum number needed in sputum smear to identify c. 100,000 bacilli/cc; 42) ... BUT since only 1 or perhaps 5-6 bacilli being 1 CFU in the smallest viable aerosol droplets to stay airborne and reach innermost alveoli, can cause spread .. even if sparse in exhalations, several months co-habiting in a barn may well effect transfer. ALSO of critical importance, is that such very low dose transfers may take much longer to progress to being reactors/then VL infectious . The traditional view that it takes 8-65 days of unresponsiveness, to become reactors may be badly underestimated, as with the overall lag between becoming infected to reactor status varying from (3-)to 6 - 20 months; 15), as demonstrated:-

a. Transmission Section6(5) experimentally, plus 15 ... taking a year plus to become infectious, and effect transfer

b. the cited Svendsson 1904 study, possibly all 13 calves became infected early on, but 5 were reactors by 6 months (2 VL), the other 8 by 12 months (1 VL) ... the ISG in contact study found c. 1/2 were reactors by 6 months p.235

c. the Good study, 24 calves probably infected together, (14 VL), but the last 4 took up to 6 years to surface ... so c. 15% of new infections very late to surface. IF they’d moved to new herds, that would have been more TB from "nowhere" ie badgers!

d. The only proven cases of badger to cattle TB transmission in a very artificial yard experiment with hindsight offers some clues ... it took much longer than expected for calves to become reactors 6 months plus ... AND the 4 calves exposed for under a month HAD NOT Seemingly caught TB, however, slaughtered too soon ... they may well have been incubating the disease !(26a); a problem in interpreting M'Fadyeans studies a century ago too (Section 6(5)). AND Secondly;

B).Unconfirmed cases.

Rather astonishingly it became "Accepted Wisdom" that both Unconfirmed and IRs Inconclusive reactors were false positives and were ignored in trying to understand the epidemiological patterns of cattle/badger TB (46 c). And yet in the mid-1980s 70-80% were positive (46c, Dunnet para 38); the ISG (21) failed to fully understand this pp. 59, 140-1, Appendix I p.233-42; and yet their own study found 60% of unconfirmed reactors positive. So, since the skin test specificity is 99.9% only 1 in 1000 will be truly false positive ie without TB, and all Unconfirmeds do have TB (18 f g) . Likewise, muddled thinking over IRs (TBF 63,& 72), although various IFN trials show positives becoming skin inconclusives IRs, then full reactors .Older studies found 7 IRs took up to 4 years to surface (Hewson, Zuckerman p.73). Hence belatedly, Wales and now England are treating ALL Unconfirmed as TB plus ... AND IRs are removed at the 1st (not 2nd) retest since they are merely early stages in the TB progression (TBEG, EC 64/432). IT is rather striking that Wilesmith's 1983 study found 71% of breakdowns in the 1970s were of unknown origin (or supposedly due to badgers) ... AND SO, Exactly the same verdict in the Green 2007 study, with up to 25% via bought-in cattle, the other 75% a hidden reservoir recycling into the cattle population, by implication Badgers again ... SO, Plus ca change!! (17, 46a).

In conclusion, as shown in the iceberg figure in Section 2, the below-sea-level hidden reservoir of cattle TB has varied components. Skin test is only 80% accurate because it misses early/late TB cases which "are the usual cause of recrudescence in herds"(Blood). And the various progression stages including actual transmission cow-to-cow, becoming a reactor, switch NVL to VL unconfirmed/confirmed, and free circulation within the population of these "missed" cases are ALL part of the problem!

Return to top

PART 2 HISTORICAL OVERVIEW

Phases A to E as seen via Figures 4 - 8.

(NB. alternative views of this graph are given in Appendix 1, and in M. Clark's Badgers, revised 2007).

The Romans and/or seventeenth century imports from Holland brought TB into GB, and by the 1940s it was spread across the whole country (map as explained in Section 4) ... but the hotspots were dramatically different then, not southwest England/Wales but the northwest due to Irish imports, which accounted for 40% of non-SW breakdowns in the 1970s (Dunnet p.43; 38, 46a). Even though high density badgers presumably occurred back then in the SW which only became a problem area with a 50% increase in stocking 1964-74 (35), and the gradual replacement of traditional Jersey/Guernseys with higher yield Friesians from the midlands (traditional Cream tea country!).

To recapitulate as in Section 4 ... there were 5 Phases Historically A - E.

PHASE A

Three early elements of Phase A which aimed at protecting public health rather than eradication per se, starting in 1935 were:-

a. removal of clinical cases under the Tuberculosis Order, 24,000 in 1936 down to a handful by the 1960s (42)
b. voluntary testing with premium bonuses for attested milk/beef, numbers joining rising as a. fell (graph in Appendix 3e)
c. pasteurization.

PHASE B

Having "thinned out" the problem, compulsory Area Eradication from 1950, working from low to high TB level areas roughly from north to south, the whole of GB was covered by 1960 (Appdx 3e map 4, graph). This textbook Area Scheme was so successful in just over a decade that TB shrank from countrywide to tiny southwest hotspots, with c. 100 herds and under 1000 reactors/year (Ritchie, Macrae; also 9, 18a, 37b, 39, 46a).

Attention focused in the early 1970s on the reasons for recalcitrant hotspots, and a Cornish study of the notorious West Penwith/Lands End area identified cattle risk factors such as imperfect tests, the importance of dangerous contacts and non-reactor anergic cows in chronic herds, inadequate double fencing (for brucellosis too), safe disposal of slurry etc (39) ... but with the discovery of the "1st" TB badger in Gloucestershire, in 1971(another Glamorgan) it switched to the 1st culls and attempts to assess badger TB risks from latrine and clinical sampling, and autopsies in Avon, Cornwall, Gloucestershire; particularly as regards Avon /Thornbury cull/Dorset, Steeple Leaze cull/Staffs/Sussex (3a;6/26/3bc, 19/46d)(NB The latter 3 counties by 1996 had produced a mere 110 TB badgers out of 4049 sampled ... see Table 1 below for top 4 county figures) ... Ironically, Staffs was the last non-SW county to go clear, but among the first when post-BSE restocking in the early 1990s reintroduced TB with "new" French DNA spoligotypes, and the new Derby/Staffs hotspot cluster being on longer test intervals exploded unnoticed to over 6000 reactor within the next decade (6a , 12).

Return to top

PART 3. GETTING THE BLAME

PHASES B AND C

The textbook Area Eradication scheme hence simply entailed a. Intensive Annual testing of the whole 9 million national herd initially (Appdx 3e Table); b. movement restriction of TB herds; c. selective depopulation of chronic herds if ½ or even ¼ of herd affected; with a similar classic scheme in Eire to safeguard their exports to GB (43). The net impact in GB was to suppress spread both within and between herds; but the "unfortunate" inverse correlation being to suppress many of these effects "Below the Radar" (as explained in Progression section above).

Thus most breakdowns were Minor ones; - minimum spread within, hence also to contiguous or exported cases, with derestriction in under a year (especially as regards unconfirmed breakdowns). Hence during the low point Phase C, it seemed as though there were only 1-2 contiguous breakdowns/a ; but the Badger Reports 1-20 have frequent references such as cull on neighbouring farm a year ago ie. there was contiguous TB. In comparison in Ulster some 70% of breakdowns contiguous, since up to 60% of farms are fragmented with up to 9 sub-holdings, per "farm" with up to 13 being contiguous to a farm with TB or brucellosis (4, 36); so misunderstanding the difference between contiguous/badger origin, the odds ration is 5.5 that an infected badger will be found within 2 km (36).

The importance of the minority of Major breakdowns in local persistence of TB is out of all proportion to their numbers; with 20:20 hindsight, 3 non-reactor or anergic cows in 1 Cornish herd caused 18 herd breakdowns, probably being all those in Madron parish (Figure 5), and being 10% of the 178 herd breakdowns over 2¼ years ... depopulation of perhaps a dozen such herds allowed Penwith to go clear by 1985, which lasted until cattle reintroduced TB 1988-9 (no badger culls needed, no resurgence from the sparse scatter of badgers in the interim (39, Appdx J & N, badgers vs high density dairy herds in most persistent hotspots of Lands End/Redruth; and see Fig. 6 also; 85 unconfirmed vs 93 confirmed breakdowns). Failure to restrict such chronic undetected herds causes incalculable damage;- one Cheshire herd accounted for 9 of the 31 breakdowns in NE England (c. a third, 16).

Attribution of the causes of herd breakdowns has always been rather an exercise in "Informed Guesswork", and often highly problematic (Zuckerman p. 79, Krebs p. 158-64, ISG Chapter 6 with TB 99s and other questionnaires; Vet field manuals in Eire & GB). Even with computerised farm & movement databases in Eire, Ulster and GB tracing back or forwards movements may be difficult, in the BCMS (British Cattle Movement Service) some 10% of c. 9 million cattle have "illogical" movements due to incorrect/inadequate data (30), and cattle passports unbelievably still lack TB test data (Lord Rooker found that to be unworkable, too costly, and difficult with "Business confidentiality" ... but the resultant costs are far higher in terms of untraced TB, its crazy that farmers cannot buy cattle without a TB "MOT" test certificate!).

Two studies highlighting problems reveal that trace back to the most immediate precursor herd may be either to one that was NVL/Unconfirmed or currently seemingly "without TB" ...whereas the actual TB source hard may have been several moves previous in the husbandry production line, eg stores to finishing herd (16, 19) so in truth these were of "unknown" origin ... a recent Ulster study suggested 39% of confirmed herds were unknown origin too (36).

During the low point, ie. Phase C in graph Figure 4, 1975 - 1985, a clear division became apparent between the southwest with "Problem badger parishes", and the non-SW (or rest of England, Wales, Scotland) with low badger numbers, and few with TB since cattle TB rare too! Hence in GB in the early 1970s Figure 5 in the north of England/Scotland; in the absence of endemic TB in either cattle or wildlife (just 1 badger and a few roe/sika deer), virtually ALL breakdowns were due to imports of Irish cattle (ie. open triangles) ... reaffirmed in the 1990s by Chief Vet J.Scudamore; and more recently with OFT-Free status and both pre- and post-movement testing (18 e).

An identical random scatter of incidents occurred n the midlands and SW even in the Lands End/Penwith area (Fig. 5 top map, c. ½ unconfirmed), most breakdowns were in truth of UNKnown origin (open circles because many were/or were from unconfirmed herds). It seems logical that these TOO were simply due to bought-in cattle. And most importantly, the random scatter of both herd breakdowns and TB badgers would suggest that badger TB was NOT Universally spread in the area, but as in the clean ring culls 1982-6 were simply the spillover in incredibly small micropockets associated with the epicentre of the cattle TB; Appdx 3e, map 5. It is rather unlikely this pattern of a wide scatter of micropockets of badger TB could have arisen if badgers were really so infectious and spreading TB throughout the badger population ... common sense would suggest this pattern is simply the effect of scattered cattle TB breakdowns with spillover into badgers; effect not cause!

Thus the source of the 1099 confirmed breakdowns in 7 years 1972-8 were 71% unknown (or supposedly badger), 25% bought-in with over half these Irish, and 3% contiguous (46a). MIRACULOUSLY, a year later 1979, middle map Fig 6 all these became "thought to be linked to badgers" which being long-winded is much more simply with a quantum logic jump "DUE to Badgers" (closed circles)!! The middle map also shows the "sudden" new north-west Cornish Hartland flare-up from nearly clear, due to relaxing to 2 yearly testing; and the Thornbury area north of Bristol, seemingly clear, of confirmed breakdowns but with underlying ongoing unconfirmed breakdowns up until confirmed cases with post-BSE peak restocking in early 1990s nevertheless (6) ... also gradual recolonisation by badgers took 10 years.

PART 4. THE UNFOLDING CRISIS - AND HOW TO SOLVE IT

Return to top

A glance at TB schemes historically show that any relaxation of intensive cattle controls allows TB to escape from containment ... this happened in many countries during both world wars (11, 31). It was particularly clear in Michigan, and Germany (Appendix 3e). And a classic case was Northern Ireland ... by 1971 just 174 reactors, a premature relaxing to 3 year testing resulted in an upswing in the 1980s onwards, but re-imposing strict controls since 2002 has halved cattle TB. Badgers regarded as merely a spillover from cattle hence 18 out of 50 with TB in the 1970s sample. A critical factor in Ulster is the high number of multi-part holdings with high throughput ... up to 70% of breakdowns hence contiguous (29) ... and so an unsurprising epiphenomenon is a 5.5 odds ratio that a TB badger will be found within 2 km of a herd breakdown; which illogically is being interpreted as justification for badger culls when they have been unnecessary all these years! (Appdx 3e, Table, Graph 5; also 36)

Tragically, gradually relaxing controls during this Phase allowed spread both within and between herds which was allowed to contribute "Unnoticed" to the developing crisis. Spread continued outwards from hotspot areas at some 10 miles/a, the supposed 1 parish wide "firebreak" meant to enclose TB didn’t work since many movements jumped beyond the 2 year test "doughnut" buffer zone (Annex E, 7a), with a steady upswing of c 18% /a. And whereas at the start of the Area scheme all 9 million GB cattle were tested (Appdx . 3e Table) ... this was gradually relaxed as regions had been TB-free for several years, hence to 2-3 yearly testing ... ALAS, by the low point Phase C, Fig 4, annual testing only amounted to under 2 million / a 1988-94; 1995-2000 it was belatedly increased to 2-3 million; only 1 million FMD 2001; 2002 - 2008 from 4 to 6 million which is still only 2/3 the national herd ... so playing catch-up inadequate to stem the rise. Annual testing in core hotspots suppressed within herd spread, BUT as shown by Mitchell's study below (30), since many movements were 20 km or more ... TB spread unnoticed both into the 2 year doughnut, and jumped beyond it as well (sadly, the TBEG 2 parish buffer may likewise fail to curbs area spread).

There were three main factors which gave a boost to this spread (as outlined also Section 4):-

a. the BSE or Mad Cow crisis peaking in 1993 with 36,000 cases needing re-stocking ... so spread particularly "between herds" (and up to 85% unconfirmed see Figures 3 & 7)

b. the 2001 foot & mouth disaster, the lack of testing, with 26,000 backlog of overdue tests lasting a year later simply allowed within herd spread ... bad breakdowns with over 6 reactors doubled 2000 to 2002, Table 2, but soon dropped back down as testing normality restored

c. dramatic changes in the dynamics of the cattle industry exacerbated things eg a drop from 260,000 herds in 1936 to 90,000 from the 1990s to now ... many villages that had 4-5 self-contained farms ended up with one bigger one using outlying extra fields to accommodate more stock (no pre-move tests between holdings even if many miles distant) ... av. 47 cows /herd 1970s, now 150 with followers ie. bigger herds more prone to developing chronic TB ... tractors replaced horses, and bigger farm vehicles meant bigger fields removing barrier hedges, and risks of contiguous spread ... 1980s milk quotas and demise the milk marketing board, apart from TB added to the halving of the dairy herd since 1997, with some 26 herds going out of business weekly now, the resultant dispersal sales including some supposedly TB-free stock ... and with changes in markets/abbatoirs, plus easier transport, more longer distance moves: all factors not conducive to restraining any infectious disease.

This spread has been very well-documented in maps given in Zuckerman/Wilesmith 1983/ Dunnet p. 8, 10. Krebs very useful Colour maps ... new confirmed p.57, new unconfirmed p. 156-7, repeat breakdowns p. 58, 91, badger culls & RTAs pp.165-8, DNA spoligotypes of both badgers/cattle clustered by local spread ... badger p.173-4, cattle p.67 (cf. GVJ p. 57, Gallagher 2009, Gopal, www.mbovis.org) and 3 lots of maps in TBEG Report (43).

Two sketches highlighting the spread amongst the cattle population (with spillover to badgers) include;-

1. By 1999, over 50% of breakdowns were occurring in areas TB-free for 10 years; Avon 15 out of 25 herds, Cornwall 103/139, Devon 54/ 99; and "frontier" counties even worse Derbyshire 6/6, Shropshire 4/5, Staffs 29/30.9 (J.Paice, per.com)

2. New hotspots arose in areas TB-free for up to 50 years simply where new incidents arose from imported cattle, in areas where 2-3-4 year testing allowed TB to explode within these index herds. The pioneers often unconfirmed or IRs as usual in the edge effect from high risk areas (Fig. 7 and TBEG maps) ... often with bad Major herd breakdowns at the epicentre eg Hereford 1993 (Badger report 18), Staffs 2001 TBF 61, Dyfed/Carmarthenshire 1994, 230 cows depopulated to avoid risk contiguous spread.

A cluster then developed from the index herd by local sales, with infilling later by contiguous spread as well as "mechanical" spread ... no such thing as a "CLOSED herd" (Appdx 1c) ... since as witnessed by biosecurity risks clearly understood with foot & mouth, and the occurrence of 70-95% of herds with other diseases (BVD, IBR, Johnes, Leptospirosis, Salmonella) ... eg. inadequate double fencing/strays, by visiting milk/feed lorries, postal vans daily, on clothing of relief milkers, shared equipment or water-courses or even slurry to get round NVZ rules, hire bulls (clusters in SW in 1990s), visits to shows or markets (clear cases eg taking TB to Guernsey after a show), rat vectors may well be underestimated since they don’t have gross lesions revealing infection yet move freely between farms (26b). THUS;-

A. One of the earliest clusters started in Sussex with a unique Irish spoligotype, 46a; but only 68 TB badgers out of 1319 sampled to 1996 there. Hartland in NW Cornwall late 1970s was a flare up of 16 herds in newly 2 year testing, resolved (again) by synchronised area annual tests (Figure 6) ... another emerging hotspot in this intensive dairying area was cut short by 2001 FMD.

B. A set of new clusters arose with the extra movements after the peak of BSE in 1993 (36,000 cases to be restocked) including, with subsequent flare-up/spillover TO badgers:-

Exmoor ... TB free for 20 years, a cluster of 25 herds, 14 confirmed ... but only 11 TB badgers in 1204 sampled before then for Somerset, then up to 80% with TB on epicentre farm, more recent spillover to red deer; Hereford/Worcs ... only 10 TB badgers out of 876 sampled previously, but the 1995/6 cull found 121 in 208 (from cows ); Shropshire/Cheshire/(Lancs more recently) but only 3 in 217 and 1 in 389 badgers TB+ in sample to 1996; Staffs/Derby only 26 in 604 , and 0 in 337 badgers with TB by 1996; but Triplet G in RBCT cull 113 in 1252 with TB ... despite over 6000 cattle by 2004 (7); Cumbria, restocking after FMD brought TB back in This seemed to come as a great surprise to many, but happened after the mid-1960s FMD outbreak, taking TB back into Cheshire ... only 2 in 190 badgers with TB previously. The Furness peninsula cluster with deer involvement was initially linked to a Shropshire spoligotype, but the VNTR sub-type type suggested Irish import/s (J.Bourne pers. comm)

C. Encroachment more locally ... Wiltshire was bad in the 1940s, but had renewed TB from early 1990s, with spillover to deer in Savernake forest. Only 398 TB badgers in 3076 by 1996, Triplet E found 163 in 1651 in RBCT culls.

The Powys new hotspot arose after FMD by infilling across mid-Wales (clear 2002) between Dyfed and Gwent/Forest of Dean/Hereford high TB areas ... 0 in 443 badgers sampled previously, but 25% of RTAs now TB +. In Wales TB was nearly eradicated, so it is significant that 1972-1996, with some 700 TB breakdowns "Mostly due to badgers" in fact MAFF'S own data found just 46 TB badgers out of 2363 sampled ... clearly these breakdowns can only have come from unconfirmed cases re-cycling below the radar within Wales (30).

Recently new hotspots are emerging in (Lancs), Leics/Yorks.

THUS, NEW POLICY. Since I left the old TB Panel in 1992, I’ve viewed with a sense of mounting disbelief the attempts to painfully re-invent a "New" TB policy; as debated (add nauseam) in the EFRA and ISG/TB Forum committees, qv EFRA 2003 report, TBF 79 & 93, advising DEFRA (7; 2004 and 2005 reports). These studies failed to re-discover that annual testing is the core element of successful TB schemes, in curbing within/between herd spread, and suppressing incidents below the radar, and that longer testing areas simply allowed TB to proliferate outwards unnoticed.

Phase C - D hence distinguished a SW area with TB badgers and a NON-SW area without either endemic cattle or badger TB, so up to 75% of new incidents supposedly of unknown origin in fact they could only have been 100% due to imported cattle. As clearly shown for Scotland and the north of England (46a, 18e, 16), and later re-stocking Cumbria etc (TBF 78).

Attempts to understand the mounting crisis and initiate practical tried and tested 1960s measures hence were hampered by the blinkered view of "Badgers as THE Main problem" ... no understanding that annual testing is the gold standard in curbing spread, (see EFRA muddled thinking Sect.3C); and no idea of not allowing free movements as soon as FMD over 2001 ... my warnings to both the Anderson/Follett FMD enquiries (see their appendices online) ignored!. Everyone seemed very surprised that restocking in Cumbria reinstated TB (Chief vet report 2003), but mid-1960s FMD restocking took TB back into Cheshire; and restocking the Aur Gelli hard recently has re-introduced BVD/IBR ... (farmers/vets were very reluctant to accept the idea of pre-movement testing (see DEFRA 7, strategy and consultations) ... far too few cattle tested to stem the flow (earlier figures) … and a tragedy that Mitchell's very clear projection (see below) that TB would recycle within hotspots was not implemented in policy until far too late ... IF the SW peninsula had gone onto annual testing 10-15 years ago it could have prevented the expanding crisis ... and the pan-Wales crisis could have been stemmed too!

It is very sad to recall that during the 1970s low point Phase C, with just 100 breakdowns /a (20-30 in non-SW and up to 75% of these unknown origin , ie untraced imports)); the seven SW counties Avon/Glos to Cornwall all fell to single figure breakdowns /year (except Cornwall) ... all now run to hundreds /year. Significantly back then the number per year in each county could double or halve according to efficiency of testing ... so hardly surprising that flare-ups occurred to 16 herds Hartland/Thornbury (like Donegal too 33a), hence these special problem areas where badger culls supposedly solved things ... Steeple Leaze was merely a cluster of 6 chronic herds ... ALL 3 areas cleared within existing cattle control downturn, culls made no difference! It is worth remembering too that BRO culls of up to 70 badgers, indeed in up to a third of culls produced NO TB badgers at all ... these "reactive" culls were in fact triggered by below the radar cattle upswings!

However, attempts to model the contribution of movement to the overall problem suggest figures of in England 10-18% 1972-86 (over half the latter being Irish imports before a 1970s vet strike prompted both pre-export AND post-import tests; or 16 (to 25% ?) in 2007 (46A,B; 17) NB interestingly these two studies 1983/2007 found hence unknown ie supposedly badgers 71%/75%; Irish figures as low as 7% , or usually 15-20% (4, 36) ... these studies didn’t fully distinguish movement of unconfirmed cattle and especially, their recycling within hotspot areas where the presence in the herd previously and TB locally were obvious predictors/risk factors for further (repeat) breakdowns eg in 75% of incidents (assumed to be badger! (4, 13, 17, 30). Indeed, the revealing studies by Mitchell et a found in 2001-2003, 7 million farm-to-farm movements, 43% were under 20 km (mean 58 km), and 21% were 20-39 km (hence leap-frogging the 1 parish 2 year test "firebreak" (Annex E, 7 a). IN 2002, 453, 000 were from the southwest, but 87% recycled within the area; only 13% going to the east/north/Wales. However moves from 1 year test areas sent 40,000 cattle each to 2 and 4 year test areas, and these occurred even within the SW peninsula, so if only 5 - 10% were TB + that’s 2000-4000 /year. Hence the inexorable outwards expansion of the SW hotspot. Exactly same scenario across mid-Wales/Powys. ALAS, the expanding crisis area was entirely predictable.

AND SO, making allowance for the fact that a new cattle TB model (20) must take into account spread of TB recycling below the radar as regards airborne cattle-cattle transmission, latency for years, and the true TB status of unconfirmed/IRs ... with early/late TB cases being the USUAL source of recrudescence (1) ... the upshot of these modelling and other predictor/risk assessment studies have shown very simply that the obvious ones given a cattle source within undetected TB (Unconfirmeds etc) are simply, previous TB in herd and in locality, movements in, and herd size and type:- every study for a century have agreed that size is critical:- a 80% accurate skin test misses 2 in 10 or 200 in 1000 so unlikely to ever go clear ... dairy cattle having longer working lives (even 20 years) have longer to develop overt TB, and tests less effective due to pregnancy/calving/anergy ... beef cattle culled much sooner before TB apparent often at 16, 24 or 30 months (BSE OTMS rule now lifted (4, 13, 15, 33b) ... and so the end stages of TB schemes often end up in the most intensive dairying areas as in the SW/Dyfed/S.Ireland (44).

TABLE 2: -GB REACTORS IN CONFIRMED NEW INCIDENTS (CNIs) AS PERCENTAGES

Nil* 1 2-5 6-10 10+ Total herds
2000 6.7 28.5 41.6 11.6 11.5 100% (1117)
2002 3.9 17.0 37.1 17.0 25.0 100% (2006)
2005 17.9 30.4 33.9 10.3 7.0 100% (2298)

** The bizarre idea of TB herds with 0 reactors are disclosed by abbatoir inspection or as inconclusive IRs!!

Return to top

Return to top

PHASE E:- IS TB STILL OUT OF CONTROL?

Given the spectacular rise in TB shown in Figures 4 & 8, and map Figure 1 ... many claim TB is still out of control and a mass badger cull urgently needed ... without however understanding WHY the THREE main JUMPS in Cattle TB occurred ... very simply, the Foot & Mouth FMD 2001, and the earlier BSE crisis allowed cattle TB to explode both within herds, hence a doubling of bad breakdown with 6 or more reactors in 2002 in Table 2, and between herds expanding inexorably into areas TB free for up to 50 years. The changes to MAFF/DEFRA policy meant simply playing catch-up with these increases (TBEG, 43); THUS, the 3 jumps:-

1. The jump 2000-2002 was due to little testing during FMD, then a 26,000 herd backlog of overdue tests. So many herds which hadn’t been tested up to 2 years were bad Major breakdowns with c. 40 VL reactors in a 150 cow herd (and "obviously"?) many NVL latent cases to surface later). The threefold jump from 8000 to 23,000 (fourfold Wales) was simply the couple of years worth accumulation of cases.

2. After levelling off 2002-2004 at 23,000, the jump to 30,000 in 2005 was simply due to the Autumn 2004 package of tighter cattle controls beginning to bite ... these included variously .... again adjusting parish testing frequencies in rising hotspots, zero tolerance on overdue tests, and to stop TB expansion into new areas ... continuation of both pre-export/post-import tests within 2 months from entry (started in 1970s after a vet strike, re. Irish imports, some 30,000 imports in 3 years also from France, other non-TB countries ... (30) ... to many a surprising number imported, but Blue tongue in 2009 was solely via imported stock); the phased launch 2005-7 of pre-movement testing England/Wales; with post-movement tests too Scotland (with a 80% accurate skin test just pre-move misses 4 in 20, with post-move too, just 1 in 20 missed , and 6 month check test safety net (18e)) ... likewise annual tests for 3 years on any herds restocked post-FMD, on reformed herds or newly registered owners (NB. these several measures, and the fact that many herds are beef finishers with rapid through-put before TB can develop, are why although peripatetic outbreaks have been occurring in the non-southwest since the 1970s, they did not become endemic!(13)) ... and lastly staggering of areas tested each year in 3-4 year test regions so lessening the potential overlooking of new incidents.

It is also very helpful that both N & S Ireland have computerised databases ... so have been able to inform folk here, those cattle we sent on xyz, were from a herd which has "since" gone down with TB/Brucellosis, please re-check!(The APHIS database in Ulster, and AHCS +CMMS for health/movements in Eire (4)). Alas, we’ve sent TB cases recently to the Isle of Man, where they rely on pre-export/post-import tests ... and of calves to Holland in 2008 which after decades of struggle to go TB-free weren’t amused! (10).

These measures caught up with the miscellaneous backlogs, hence the drop to 24,000 reactors in 2006.

3. The big jump then to nearly 40,000 reactors in 2008 was once again simply the accumulated cases caught by adding c. 1000 parishes into annual testing from Nov. 2000, especially in Devon/Dyfed. Hence again initial bad breakdowns in big dairy herds with many VL cases, even cases of udder TB so permitting infection of batches of calves by bulked milk (Maps as shown Section 3(3)Efra) . That largely accounted for the doubling in Wales from 6000 in 2006 to 12,000 in 2008 via cattle spread (but of course knee jerk demands a badger cull). The Welsh history is particularly interesting given the proposed cull 2010; THUS:-

WALES ... It is remarkable that in the 1940s the TB area was Glamorgan (map in Section 4) hence the very old record of the first Welsh TB badger c 197l(9). The pattern became dramatically different after that ... so TB nearly eradicated by the national area scheme ... with tiny remnant in Dyfed in 1970s Figure 5, from there to 1996c. just 700 breakdowns, "mostly" due to badgers, but MAFFs own figures show just 46 TB badgers out of 2363 sampled ie. the hidden unknown source can only have been unconfirmed or hidden cattle cases. This residual pocket was in the most intensive dairying area, and hardly surprising that ½ ie.23 of these 46 badgers were in Dyfed.

Sadly as in the rest of GB relaxing cattle controls allowed the gradual expansion of the Dyfed hotspot, with another spilling from Gloucestershire into Gwent in early 1990s, Figures 1, 5 & 7. Changes to more annual testing parishes in Dyfed 1991, Gwent 1995 belatedly attempted to curb the spread. But just as Mitchell's study found most farm-farm movement recycled within SW and other regions, so too in Wales ... the 2-3 year test areas hence experienced gradual creep inwards (30, 18c ) ... closing the gap clear in 2002 between Dyfed/Gwent ie. Powys ... no TB badgers previously, but suddenly 25% with TB in RTAs. This cattle spread is elegantly shown by the DNA spoligotypes of cattle (then spillover badgers) as seen Krebs p.67, 173-4; and ref 18d p.57 www.gvs.gov.uk 2006). There were just 700 reactors in 1997, but the huge jump from 2006 to 2008 from 6000 to 12,000 was simply because many 2-3 year parishes brought back into annual testing, with many bad breakdowns with many VL cases (see maps of parish testing from Nov. 2006 Sect. 3C).

Similarly the Welsh Health Check has added c. 95 new herds and 1000 reactors by testing outside usual areas. In the proposed cull area 42% of herds have had a breakdown since 2003. Given a cull of c. 1500 badgers from 288 sq.km (a pinpoint in the whole of Wales) ... that may be 2-300 with TB or 1/sq.km, so the cull won’t make the slightest difference. It is a great pity that responding to this clear cattle explosion, Dr Glossop, Elin Jones, Meurig Raymond and Evan Thomas (WA, NFU, FUW) so keen on a badger cull don’t seem to understand that these are "cattle problems"; not Old Brock at all!!!? It is great pity someone cannot persuade them that with bad Welsh breakdowns in big dairy herds, under restriction 10-15 years, the obvious answer is to find non-reactor ie anergic cows within HOURS by antibody test/PCR SEE Section 3b Viewpoint ... QV cows lost in herds include Trioni 800 +, Cilast 500, Pedron 200, Gelli Aur 300, with reintroduction of BVD/IBR in restocking.

It would seem that the final figures for 2009 will show a drop of a few thousand as these measures begin to bite, as also shown by ISG follow-up (See Quo Vadis section above, (22)). ALAS … given the latest tightening of measures from January 2010, including making ¼ of GB an annual test area (so removing the inconsistency of 1 and 4 year testing areas being next door) and hence the "edge" effect in which expanding areas are pioneered often by unconfirmed or IRs which DO have TB, Plus measures to ease farmer inconvenience via dedicated dispersal sales, and AFU/AQU Approved quarantine/finishing units (TBEG, 43).

These Measures will almost certainly produce another catching-up jump to 50,000 - 60,000 reactors in 2010 ... a Final Peak?? (A peak predicted by DEFRA 2004, but Assumed to be due to badgers!).

Return to top

LOOPHOLES IN THE NEW POLICY

Sadly, there are a number of "gaps" in policy as to "Surveillance" tests/tracing

1. The skin test is only 80% accurate, or 65% on retests, ie misses 1 in 2 early cases yet to surface, likewise misses 2 in 10 singleton breakdowns (21) ... cost/resource limitation means only 1 reactor sent for culture confirmation, may miss 9 out of 10 including the VL spreader case in multi-reactor breakdown

2. A third of cows may be non-reactors temporarily after calving, easy to avoid anergic period in spring/autumn calver herds, repeat testing does desensitise (20, Coad) and vaccination for Johnes disease upsets test too (sub-type of avian TB)

3. Abbatoir inspection serves as a safety net ... at low point only 20-30 cases/yr, but now over 1000. It must be worrying in Southern Ireland that up to 46% of cases are found at slaughterhouses ... ie annual testing NOT 100% effective; the abandoning of pre-movement tests in 1996 caused a blip up (like FMD blip in proactive areas (21b); and so with 10% of derestricted herds still having residual TB, and peak sales in first 2 months there is clearly "leakage" in the surveillance (4, 36).

It is worth remembering that the new ERAD intensive 4 year scheme from 1988 found up to 42,000 reactors/a where in previous years there were around 30,000 (going back decades; see Table in Appdx 3e) ... and yet the true number of reactors "out there" was actually c. 60,000 ... so prior testing only skimmed off ½ the additional problem each year. Remarkably the last decade has hovered between 25-30,000, eg 27,000 in 2008 ... so testing isn’t achieving a reduction. Ironically the Offaly badger cull also started in 1988, hence the big drop due however to cattle controls, a mere 141 TB badgers culled (see Sect.6 (2)) ... and culling c 5000 badgers/a has had no effect because it’s the wrong target! It is sad to reflect that since the "1st" TB badger in Ireland in 1975, well over 75,000 badgers have been culled with no demonstrable effect ... ERAD and now CVERA have made huge strides in reassessing cattle TB ... unlike on the whole in GB; but the blinkered adherence to further culls or badger vaccines are a tragic waste of time.

4. There is no pre-movement testing in GB between multiple holdings ... which can be widely separated eg Wilts/Cheshire, Glos/Aberdeenshire, and whilst applying from 1 & 2 year areas to 4 & 4 year test areas, spread Into 2 year areas allows new hotspots to develop a la Hartland ... and as explained above by Mitchell's data.

5. A major problem is that until now unconfirmed cases have been ignored wrongly as false positives, but such herds ARE STILL derestricted after 1 clear test ... Inconclusive IRS are to be removed at 1st re-test not 2nd, EC 64/432. And of course trace back often finds the "first" prior farm may be unconfirmed or supposedly TB-free (16, 19).

6. Farmers are warned not to buy stock from dodgy areas ... but it is crazy that cattle passports don’t have latest TB test results; and the BCMS movement database is still not 100% effective (c 10% illogical moves 2003; 30)

7. It is of course sensible to target testing effort ... annual testing is a blunt instrument since most herds don’t have TB, c 50% of effort Eire, with the rest on more targeted eg contiguous, 6 m check, abbatoir follow up etc tests (36). With TB long absent in Michigan 6 m check tests for 7 years, just 2 in Eire since annual testing resumption more effective.

8. DEFRA TB statistics data is valuable ... but misses some key elements eg in 2008 c. 5000 new incidents, BUT overdue had slipped to 5000 herds again, and the 7500 under restriction therefore presumably includes some 2500 chronic or ongoing breakdowns?

9. UNPasteurized … Alas, with TB likely to reach 60,000 reactors in 2010, that is four times worse than 1960, up to 1 in 4 herds Gloucestershire, surely it is unwise not to ban Green top milk/soft cheeses (c 200 herds), with risks to humans, TB, E coli O157, Campylobacter, etc ... an increase in cases of "atypical "mycobacteria reported by GPs who haven’t met human or bovine TB patients before.

Return to top

REFERENCES

1. Blood 1989 Veterinary Medicine.

2. Carter 2007 Proc.Roy.Soc. 274,2769 perturbation.

3. Cheeseman A. 1981 J.Appl.Ec. 18,795, four area culls ... B. 1985a Mam .Rev. 15,125, Staffs ... 1985 b Acta Zoo Fennica 173,197 clinical sampling.

4. Clegg 2008 Prev Vet Med doi, premovement tests Eire (See Griffin 1992/3, Ir.Vet.J.45,126/46,143).

5. Costello 1997 Vet Rec 141,222 anergic cases, hence antibody ELISA 1997 Ir. Vet.50,35, SEE Also Lepper 1977 Aus Vet J. 53, pp.214 & 301.

6. Clifton-Hadley 1993 Epid Infect 114, 179 Thornbury.

7. DEFRA A. 2004 Preparing for a new TB Strategy ... B. 2005 Government Strategy framework for the sustainable control of bovine TB ... C. 2005 Consultation, Controlling the spread of TB: badger culls ... WITH 3 Key extra reports added, Wilsmore et a on wildlife role internationally. PLUS the RIA and Stakeholder reports on pre-movement testing.

8. Dunnet 1986 Report.

9. Evans 1981 Anim Regulation Studies 3,191 early TB scheme.

10. Fischer 2005 Prev Vet Med 67, 283 cattle models Holland.

11. Francis A. 1947 Bovine tuberculosis ... B. 1958 TB in animals and man.

12. Gallagher 2009 Cattle Practice 17,45 badgers are the main fountain head TB reservoir.

13. Gilbert 2005 Nature 435,491 (NB ALSO Wint 2002 Trend Mic. 10,441 & DEFRA Project Reports SE 3023, SE 3034) models.

14. Good 1994 ERAD papers, 45 latent TB, (Also See Griffin 2002 ERAD, 54; % infectIOUS by months from infected).

15. Goodchild 2001 Tuberculosis 81, 23 a key review of cattle parameters.

16. Gopal 2006 Vet Rec 159, 265 north-east cattle introductions.

17. Green 2007 Proc Roy Soc doi, cattle model.

18. GVJ Govmt Vet J Vol. 16 Bovine TB, www.gv s.gov.uk ...pp.a. 11, Proud historical/b. 19, EU TB-FREE /c. 46, Cattle model (SEE ALSO Mitchell)/d. 53, lab tests DNA spoligotypes/e. 58, Scotland/f. 65 UNCONFIRMED, (SEE also Rua- Domenech 2006 Res Vet Sci 81,190)/g. 72 IFN tests trials.

19. Hewson 1987 Vet Rec 120, 252 Staffs tracing cattle (SEE Cheeseman 1985 a badger side).

20. ICMB 5, N. Zealand Conference abstracts Handbook online. SEE esp.pp. 58 Conlan/136 Whelan new cattle TB model needed /101 Coad repeat tests desensitize.

21. ISG A. 2007 Final Report on RBCT/Krebs culling trial ... B. 2005, 29 Sept. Report to Minister (A, www.defra.gov.uk/animalh/tb/ISG/PDF/finalreport.pdf)

22. Jenkins 2008 Internat. J. Infect Dis. 12,457 alleged effect on cattle 2 years after badger cull ended.

23. Jubb 1985 Pathology of domestic animals.

24. Kao 1997 Proc Roy Soc 264, 1069 cattle model:- cattle controls alone will work.

25. Krebs 1998 Report.

26. Little A. 1982 Vet Rec 111,550, badger/calf yard experiment ... B. J.Hyg.Cambr. 89, Parts I- III pp. 195 (Wilesmith), 211, 225, Steeple Leaze cull, Dorset, ALSO 1982 Vet Rec 110,318.

27. Macrae 1961 Symp Zool Soc 4,81 GB area scheme.

28. McDonald 2008 Trend Ecol Evol 23, 53 perturbation.

29. McIlroy 1986 Vet Rec 118,718 early cattle lesions/infectivity.

30. Mitchell 2005 Anim Sci 80, 265 cattle model (also GVJ p.46).

31. Myers A. 1940 Mans greatest victory over tuberculosis ... B. 1968 Bovine tuberculosis control in man and animals.

32. Neill 1988 Vet Rec 122,184 cattle lesions/infectivity.

33. Olea-Popelka A. 2007 Ir. Vet J. 59, 683 cattle flare-up in Donegal with contiguous spread, B. 2008 Prev Vet Med 85, 81 risk factors.

34. Perez 2002 Prev Vet Med 54, 361 cattle model Argentina.

35. Pout 1981, 12 Dec. Vet Rec 541 ... cattle population doubled.

36. Prevent.Vet Med 2006 Vol 112 = ICMB4, DUBLIN CONFERENCE PAPERS pp. 101 EC TB-free/181 Palmer diagnosis/231 Ulster/239, More, S. Ireland Overview.

37. Pritchard A. 1987 Epid Infect 98, 145 clinical study ... B. 1988 J.Comp.Path. 99,357 a critical centenary overview.

38. Rees 1981 Nature 290,623 ... Irish imports.

39. Richards 1972 Inquiry into bovine TB in West Cornwall.

40. Ritchie A. 1959 in Stableforth Infectious Diseases of Animals II, p. 713 GB area scheme (Also p. 687 Stamp cattle lesions); B. 1964 Conquest 52, 3 ... C. Animal Health MAFF Centenary volume.

41. Smith 1995 Mammalia 59, 639 clinical badger cases.

42. Steward 1941 Vet Rec 53,521 clinical cattle cases.

43. "TBEG TB Eradication Group Report Oct. 2009" JUST GOOGLE IT … devising a bovine TB policy NB p.24 UNconfirmed and Inconclusives HAVE TB! Also new AQU/AFUs Accredited Quarantine or Finishing Units, cf Farmers Guardian 18 Dec/Farmers Wkly 8 Jan 2010.

44. Watchorn 1965 Bovine tuberculosis eradication scheme 1954-1965, Dublin.

45. White 2008 Trend Microbiol doi. Perturbation.

46. Wilesmith A. 1983 J.Hyg Cambr. 90,159 ... B. 1986 Vet Rec 118,51 ... C. Epid Infect 99, 173 non-visible lesions cattle ... 1986 J.Hyg Cambr. 97 Parts I-IV, pp. 1, 11, 27 (Pritchard), 37 ... the Sussex study.

47. Woodroffe 2005 J.Appl.Ecol. 42, 852 cattle risk TO badgers.

48. Zuckerman 1980 Report ... pp. 86, 94 Only "Open" lesion cases supposedly infectIOUS.

49. Stop Press! more detailed badger autopsies, Murphy 2010 Res Vet Sci 88,1; Jenkins 2007 Epid.Inf.doi (re ISG data); Crawshaw 2008 Vet Rec 163, 473

Return to top