Government trials to see if the spread of tuberculosis in cattle can be controlled by killing badgers have only spread the disease further, scientists have discovered.
The findinghas stunned ministers, officials and the scientists themselves. It led yesterday to the immediate abandonment of half of the controversial culling trials, which have cost £25m in the past five years. It throws into doubt whether culling badgers, known to be carriers of the disease, can ever be a realistic policy option in the fight against bovine TB, which is slowly increasing in Britain's cattle herds. Many farmers have been strongly in favour of it, but animal welfare groups have been opposed.
So far more than 8,000 badgers have been killed in the large-scale culls by being trapped and then shot in 10 separate trial areas, mainly in the West and South-west of England, where bovine TB has been most prevalent.
The trials, which were due to last until 2005, were set up at the suggestion of Sir John Krebs, an animal behaviour expert from Oxford University (and now chairman of the Food Standards Agency) who reported in detail on the possible interactions between cattle, badgers and TB. The aim of the trials was to find out what proportion of TB outbreaks in cattle was caused by badgers and whether culling the animals was an effective way of controlling TB in cattle.
Two types of cull have been going on: so-called proactive culling, which aims to reduce badger numbers to low levels over areas as large as 100 square kilometres, and reactive culling, which kills badgers near TB-infected farms.
Both were being considered as possible future policy options and the culling experiments were designed to evaluate them. But the Government has been forced to backtrack swiftly after discovering late last month its experiment was a case of the medicine making the patient worse. Had it not done so it would have faced immediate accusations from angry farmers that its own policy was aggravating their problem.
It is the reactive culling in TB hotspots that has been counter-productive. With remarkable consistency across all the trial areas, reactive culling has caused an average increase in TB outbreaks of 27 per cent. Although this may seem to go against common sense, the scientists supervising the trials explain that in practice no more than 80 per cent of badgers in the infected area are caught. The survivors no longer live in stable social groups, and are more likely to wander about the countryside, spreading disease as they go.
Professor John Bourne, chairman of the Government's Independent Scientific Group on Cattle TB and the man ultimately responsible for the trials, said yesterday "perturbation" of badger populations because of the culling was the likely reason for the increase in outbreaks of the disease.
Ben Bradshaw, minister for Animal Health, who yesterday announced the reactive culling was being halted immediately, said: "A popular analogy would be that you stick a stick in a hornet's nest, and by stirring things up you make the situation worse."
The proactive culling is still continuing because there is not enough data yet to say what effect, if any, it has on the incidence of cattle TB.
But there is no doubt that the reactive culling, which Mr Bradshaw said for most people was probably the more attractive option, had now been firmly ruled out. There were other policy options available, Mr Bradshaw said, which included increased biosecurity on farms and testing of cattle before they were moved. There is no effective vaccine for bovine TB and Professor Bourne said it might be a decade before one was produced.
The unexpected result of the culling did show there was a link between badgers and TB in cattle, Professor Bourne said. "I think it shows very clearly that badgers are involved in the transmission of TB," he said. "What it goes on to show is that localised culling will not control TB in cows, but will be likely to make it worse."
For this reason he strongly cautioned farmers who might want to kill badgers against taking the law into their own hands. "This data should indicate very clearly that that is counter-productive," he said.
Farmers expressed concern about the decision to suspend the "reactive" part of the trial last night. "We need more information on how this decision has actually been reached, particularly in light of the huge delays and disruption in these trial areas," said Tim Bennett, deputy president of the National Farmers' Union. "We cannot look at these figures in isolation. We must have information on all aspects of the trials."
But Elaine King, chief executive of the National Federation of Badger Groups, welcomed the decision. "These extraordinary results confirm the warnings that I and other scientists have been giving for years. It also means that farmers who have been illegally killing badgers have actually made their situation worse rather than better," she said.
"We congratulate the minister for acting decisively on the information currently available. We need to find the most effective way of controlling bovine TB. [The Government] has already accepted that cattle-to-cattle transmission is significant and we need to look at other measures to control the spread, such as stricter movement restrictions and more frequent testing."
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