Deadlier than foot and mouth

Ulcers start appearing around the mouth, nose and eyes. Then the neck starts to swell, followed by the head. There is lameness. The virus multiplies and soon the beast starts bleeding internally. Breathing becomes more difficult. Death is close.

But this is not foot and mouth. Indeed, there will be few farmers breathing a sigh of relief this weekend as it appears that threat has, for the moment, abated. For they know something potentially as damaging is a mere gust of wind away. Bluetongue is heading this way.

Bluetongue has rampaged north across the Continent, killing 1.8 million animals in less than a decade. This time it is sheep that are the main victims, with the most virulent strains of the virus wiping out up to 70 per cent of infected flocks in two weeks. There is no cure and no vaccine.

For farming communities reeling from BSE and foot and mouth it is the latest nightmare - and thanks to climate change it appears unstoppable.

While it originated in Africa, bluetongue has found its way across the straits of Gibraltar and up to the fields of Holland, Belgium, France and Germany. The reason it has moved so quickly is its carrier: the humble midge.

Yet a variety of the midge has wrought havoc on sheep populations throughout Europe, and experts now say it is unlikely that Britain's 34 million sheep will remain unscathed for much longer.

They expect that following higher temperatures and recent floods it may merely be weeks before the sight of dying animals, with their tongues tinged blue as a result of asphyxiation, greets beleaguered British farmers.

Climate change has ensured that the risk of bluetongue arriving in Britain has never been greater, according to Professor Peter Mertens, head of arbovirus research at the Government's Institute for Animal Health (IAH) in Pirbright, Surrey.

"We have all the elements for an outbreak. Bluetongue has never been in the UK before, so we have a high-risk population with no immunity. It's a serious worry. All it needs is the match to light the fire - the arrival of the virus, via a single infected midge, is all it takes," he warns. "The risk has never been higher ... we are very nervous about it. The real horror story is if we get bluetongue and foot and mouth at the same time."

It is a deadly strain of

bluetongue, known as BTV8, that has found its way from sub- Saharan Africa to northern Europe, and further outbreaks were reported in the Netherlands last week.

For scientists, this is their worst fear realised - that the virus has survived winter and can now live at the same latitude as most of southern England. Now just 100 miles away, bluetongue could cross the Channel in a single day, given the right weather conditions and winds.

Experts now expect the virus to arrive in Britain at any point. Swaths of the countryside will need to be sealed off. The way in which the virus spreads, by midges instead of from animal to animal, means that officials would have to draw up 150km exclusion zones - 15 times the size of the 10km zones used to contain foot and mouth.

And animals could be subject to dusk and dawn curfews, to minimise risks of infection at times of the day when midges are at their most active.

Bluetongue presents no immediate danger to humans, and given the nature of the disease spreads in small clusters as opposed to the rapid sweep foot and mouth can make across the countryside. So the threat is different, but no less pressing, say scientists and farmers.

Nick Blayney, president-elect of the British Veterinary Association, says the symptoms could mean that people mistake it for foot and mouth.

"The symptoms of bluetongue are vague and don't immediately point to the disease, but swelling of the head of neck, ulceration of the mouth, nose and eyes, and lameness are all signs of the disease.

"In the early stages it could be confused with foot and mouth, because of the similarity in symptoms," he says. "The virus multiplies and damages organs, causing internal bleeding and ultimately death - the majority of sheep will die of it in the early outbreaks.

"Bluetongue is right on the edge of the Channel now and it would seem to be a practical consequence of global warming. It is a question of when, rather than if. It is not going to spread dramatically in the same way that foot and mouth can, but the worrying thing is that it will be difficult to stamp out because it is an insect-borne disease."

The bad news for farmers in Kent, Essex and East Anglia is that they are right in the line of fire, with little to protect them but the hope that scientists are able to pick up any signs of the disease in time to stop it from taking hold here.

In a research paper published in the Veterinary Record this year, scientists from the Institute for Animal Health predicted that the summer months leading up to October are the most likely time for bluetongue to cross the Channel - with Britain at risk of easterly winds, which could allow infected midges to be blown across the Channel between four and seven times a month.