Facing up to the terror of rabies

BATS were one of his great passions. When he was not painting them, he was working with them, counting them for a wildlife census or carrying out surveys on their habitats or behaviour.

David McRae had worked with bats for more than 15 years, but it was this dedication that was to claim his life.

On Sunday, the 56-year-old wildlife artist became the first person in 100 years to die after contracting rabies in Britain. His death, in an isolation ward in Dundee's Ninewells Hospital, came after he was bitten by a species known as Daubenton's bat, and has prompted Scottish Natural Heritage to suspend licences indefinitely to work with bats.

Although the disease carried by bats - known as European Bat Lyssavirus (EBL) - is not the same strain as that carried by dogs and foxes, it results in similar symptoms, and, once the symptoms have appeared, almost always ends in death.

The rabies virus is carried in an animal's saliva or nerve tissue, and usually enters through a break in the skin, through a bite or scratch. The incubation period is generally between three and eight weeks, although it has been known to be as short as nine days and as long as seven years.

If the victim is treated promptly, a vaccination regime over 28 days is almost invariably effective, but once the symptoms appear, there is no effective treatment, according to Dr Deborah Wilson, consultant at the communicable disease control unit for County Durham and Darlington.

"Rabies is a brain inflammation - an encephalitis - and it might make you feel anxious or uncomfortable to start with, with problems then developing with the nervous system," she says.

"People have problems being able to swallow, and they can suffer breathing problems because of the effect on the nervous system."

It is this which gives rise to two of the most common conceptions over rabies infection - frothing at the mouth and a fear of water.

'You find it hard to swallow your own saliva, so you are not actually frothing at the mouth, but you might be dribbling saliva," says Dr Wilson. "And if somebody offers you a drink of water, they might think you are frightened of it, but the truth is you are having problems swallowing. It is a very frightening image, but it is very much exaggerated."

Once the symptoms have appeared, the only treatment is to make the victim as comfortable as possible. The effect on the nervous system and the damage done by the brain swelling means death soon follows.

But if the victim is treated before the symptoms have appeared, then a course of vaccinations and an injection of antibodies at the site of the wound almost always stops the virus from taking hold. And, contrary to another popular belief, this does not involve injecting a large needle into the stomach, says Dr Wilson.

"The needle is not particularly large, although if you have already got a wound and somebody injects into it then it might be rather uncomfortable," she says. "And the sooner you have your immunisation after you have been bitten then the more effective it will be.

"It can be hard to diagnose at first, but if you do get bitten it is important that you don't wait until you are unwell before you seek medical attention."

A vaccination is also available to people who work with animals which may be infected with the rabies virus, including those who work in quarantine kennels. Scottish Natural Heritage "strongly advises" all its volunteers who work with bats to have the innoculation, a procedure which is now under review.

The spectre of rabies has largely been absent from these shores, ever since it was eradicated in the UK in 1922 after the introduction of quarantine measures for dogs. The Pet Travel Scheme, brought in two years ago, requires all dogs to be vaccinated against rabies if they are to avoid quarantine.

There have been around 20 cases of rabies in people in the UK since the Second World War - in all of the cases the victims picking up the infection while abroad, with the latest the result of a bite from a stray dog in Nigeria in 1996.

Worldwide, there are around 35-40,000 cases of rabies every year, with the vast majority in developing countries. Although it is not unknown in Western Europe, it is still very rare for humans to be infected.

Rabies has been known to have been spread via corneal transplants, but the introduction of new screening measures means there have been no reports of this method of infection over the last 15 years. There are no other documented cases of human-to-human transmission.

While the disease is generally associated with dogs and foxes, it has been found in a range of warm-blooded animals, including pine martens and sheep. But a spokeswoman for the Department for the Environment, Food and Rural Affairs (Defra) says Britain's bat population was not thought to be widely infected with EBL.

"We have been doing surveys on bats and have only found two so far that have had rabies. We don't think it is a major problem in this country, although we will be doing another survey next year," she says.

One of those two bats was found at Newhaven, Sussex, in 1996, and the other in Lancashire in September this year, after a conservationist was bitten by a bat which was behaving strangely. The conservationist was vaccinated soon after the bite.

But, even if infection is more widespread among bats, there is no reason for the public to become alarmed, says Dr Wilson. "Being bitten by a bat is an extremely unusual thing to happen. They're not aggressive animals, and people who have been bitten by bats are almost exclusively bat handlers," she says.

"Not all bats, by any means, carry rabies-type viruses, and the chances of being bitten by a bat are extremely small. There is no need for people to be concerned, but if anyone does get bitten by a bat, they should seek medical attention immediately."

The prospect of rabies taking hold among the animal population, and putting humans at risk, may be a terrifying one, but it is also a very remote one.