27-03-2013 09:14 AM | Animal Health, Cattle, News

Badger to cattle TB infections are rare, says research



Badger to cattle TB infections are rare, says research
The passing of bovine tuberculosis (TB) from badgers to cattle may be a 'rare' occurrence on farmland, according to new research by the Royal Veterinary College.

Only four out of over 500,000 badger-to-cow contacts were recorded by the surveying team; direct interactions were defined as within 1.4 metres. This report comes as earlier in the month Farming Minister David Heath said a cull was 'backed by science.'

Indirect interactions (visits to badger latrines) were far more frequent than direct contacts, with 400 visits by badgers and 1700 visits by cattle recorded, the published journal 'Epidemiology and Infection' revealed.

During the study, half of the badgers tested positive for TB, however the infection status of individual badgers did not affect the frequency or duration of their visits to latrines located on pasture grazed by cattle.

Bovine tuberculosis, caused by infection with Mycobacterium bovis, is endemic in cattle in parts of England and Wales and its control is hindered by the presence of infection in the European badger. While M. bovis is clearly transmitted between cattle and badgers, it is has not previously been known where, when or how often transmission occurs.

Dr Julian Drewe from the Royal Veterinary College who led the study, said: "Our findings reveal that direct contacts between badgers and cattle at pasture are surprisingly rare, despite ample opportunity for interactions to occur, suggesting that the two species may be ignoring or even actively avoiding one another.

"The study was conducted in an area with a high badger population, so it is likely that such direct contact will be even less frequent in areas of the country where there are fewer badgers.

"Indirect visits by both species to badger latrines were significantly more common than direct contacts between badgers and cattle, which suggests that these represent the more typical nature of interspecies contact. Future research aiming to quantify TB risk to cattle from badgers might be best to focus on indirect contacts occurring at latrines and on contacts occurring away from pasture, for example in farm buildings.

"This clearly has disease management implications, and more work is now needed in this area to look at how such contact can be limited, to reduce the number of cases of bovine TB in the future."

Farming Minister Heath said: "Evidence has shown that culling, when carried out properly, can play a significant role in helping to reduce the spread of bovine TB. And with the spread of TB expected to cost the economy £1billion over the next ten years if action is not taken, we can't afford to sit back and do nothing."

In 2012, the spread of bovine TB led to the slaughter of 38,010 cattle in Great Britain, a 10% increase compared to 2011, according to statistics.

The published results highlight the growing impact of the disease on the UK dairy and beef industry and emphasise the 'need to take urgent action to reduce the spread of TB', the Department for Environment, Food and Rural Affairs said.

Carl Padgett, past President of the British Veterinary Association said: "The figures remind us that urgent action is required to help us get on top of this disease."

"We need to ensure compliance amongst farmers with the tougher cattle control measures, a strong push from the Government on cattle and badger vaccination, and support for measures to tackle the disease in badgers through piloting a targeted, humane cull."

Environment Secretary Owen Paterson confirmed two badger cull schemes are to go ahead in the summer to tackle the spread of TB among cattle.

Paterson said: "Bovine TB is spreading at an alarming rate and causing real devastation to our beef and dairy industry."

Paterson also announced a reserve pilot will also be prepared in Dorset in the event that unforeseen circumstances prevent one of the cull areas from being used.

But recent research conducted by Durham University claimed a widespread badger cull will have no impact in solving the problem of tuberculosis in cattle.

Professor Peter Atkins, from Durham University's Institute of Hazard, Risk and Resilience investigated the spread of the disease.

"Badgers almost certainly play a part in spreading the disease, but my conclusion is that their impact over the decades has been far less than suggested" said Atkins.

"Very carefully arranged culling may have a part to play alongside other measures in areas of particular prevalence such as South West England and South Wales, but my research suggests that extending the policy elsewhere may neither be justified nor particularly effective. It certainly won't be a panacea."

However, Paterson said he was determined no further delays are made this year: "I am determined that there are no further delays this year. That is why we have taken the sensible step with the farming industry to elect a reserve area that can be called upon should anything happen to prevent culling in Somerset or Gloucester."

But Atkins claimed that 'no one' has yet proved which direction the infection travels between species and that the disease is a 'spillover' from cattle rather than an endemic condition. He also claimed a cull could even 'exacerbate the problem'.

"The Randomised Badger Culling Trial, which ran from 1998-2006 indicated complex, interwoven patterns of infection and concluded badger culling was unlikely to be effective for the future control of bTB."

"When badgers are disturbed, they seem to perceive they are being attacked and move from their original area by a kilometre or more and join other badger groups, which spreads the disease."

Comments

27-03-2013 11:52 AM | Posted by Clued-Up
As Dr Drewe says, research is urgently needed to investigate whether bTB can be transmitted by either species (cattle and badgers)simply by both species using the same land area.

I understand researchers have long held the view that bTB is most likely to be an airborne disease, transmitted by cattle in close proximity to each other.

In view of what we know about TB as a human disease, it seems unlikely the typical indirect contact between cattle and badgers at latrine areas could transmit bTB.
29-03-2013 13:10 PM | Posted by MJ
@Clued-up "...... research is urgently needed to in........"

http://bovinetb.blogspot.co.uk/2013/03/repeat-repeat-and-repeat.html
29-03-2013 13:36 PM | Posted by t bayly
It worked pre legislation of c. the 1980. It is working in Ireland. Where there are no badgers there are far fewer outbreaks of bovine tb. The rest of the world look on in incredulity to the absurd situation of preference given to badgers over cattle. Get real. reinstate what worked.
29-03-2013 20:30 PM | Posted by Experienced
Clued up . . . You are clearly not !
As t bayly states above, until the 80s control of infected badgers meant control of bovine TB
Vets know this and farmers know this
Also infected badgers are a danger to clean badgers
29-03-2013 22:53 PM | Posted by MJ
@Clued-up
I understand researchers have long held the view that bTB is most likely to be an airborne disease, transmitted by cattle in close proximity to each other.
..........
Not so. Look up the Pathman project
snip
And they conclude:
"The overall conclusions of this Defra published report have increased our grave concerns regarding the ISG recommendation that controls on cattle alone would be relied upon to reduce the incidence and the spread of bovine Tb. We believe the ISG has seriously overstressed the importance of cattle-to-cattle spread, and the adoption of this recommendation will not control the disease. Progress will only be made when the original source of cattle infections is addressed and that means facing the reality of the large reservoir of Tb in wild badgers."
30-03-2013 21:52 PM | Posted by Jude W
Would your commentators please look at the stats and graphs-there is the same downward trend in Northern Ireland as in the Republic-where they have had badger culls since 2004-NI achieve the same and probably more healthy cattle through cattle measures-movement/bio-security and improved animal husbandry-note-A BADGER CULL WILL SOLVE NOTHING!
30-03-2013 23:10 PM | Posted by MJ
Be afraid of Tuberculosis - be very afraid

http://www.news.com.au/national-news/queensland/outbreak-of-deadly-tuberculosis-strain-a-disaster/story-fndo4ckr-1226498899517
31-03-2013 21:06 PM | Posted by JohninCornwall
I find it telling that the minister refused to support action against pesticides which it is thought could be a cause of the catastrophic collapse in the bee population - claimed he needed more scientific evidence. Yet when it comes to the culling of badgers, a move which finds few supporters in the scientific community, or elsewhere, he claims the science is on his side.
A cynic might wonder who is whispering in his ear. I expect he's looking towards a future outside of politics because even he must realise what a disaster any attempt to push through the badger cull will be, reflecting badly on the whole government. Not a way to make friends or influence people.
01-04-2013 09:12 AM | Posted by MJ
@JudeW

http://bovinetb.blogspot.co.uk/2004/07/cattle-to-cattle-irish-way.html

http://bovinetb.blogspot.co.uk/2007/07/tale-of-two-countries.html

maybe some in N. Ireland have since learned from Eire?
05-04-2013 16:14 PM | Posted by paul forrester
it could have been florence nightingale who determined that human tb spread if beds were closer than 18"
02-07-2013 00:38 AM | Posted by Julia Michell
Paterson talks about devastation to the cattle industry. 28000 were slaughtered last year for bTB herd outbreak. But also, dairy production is too high and more than 2 million cows are slaughtered annually in England and Wales for meat.
09-08-2013 22:23 PM | Posted by Graham
"The passing of bovine tuberculosis (TB) from badgers to cattle may be a 'rare' occurrence on farmland,"
" "Our findings reveal that direct contacts between badgers and cattle at pasture are surprisingly rare, despite ample opportunity for interactions to occur,"
"my research suggests that extending the policy elsewhere may neither be justified nor particularly effective. It certainly won't be a panacea."
But who is listening - certainly not the government.
22-08-2013 14:38 PM | Posted by Judi Moore
Scuse my ignorance - but does bTB actually make badgers ill, or do they just carry the disease once cattle have infected them?

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