June 8, 2004

 

 

Mystery Brain Disease Afflicts UK Cattle
 

A possible new cattle disease which might pose a risk to human health is being urgently investigated by government vets.

 

Tests on a heifer that died after five to six days of weakness in its legs and progressive paralysis have failed to identify any known condition, including BSE. A viral infection that damaged the white matter in the cow's brain is thought responsible for the death more than two months ago.

 

The animal was at first thought to have died from botulism, a condition that is potentially dangerous to people through infected milk and food and is responsible for similar symptoms.

 

But that test proved negative, as did checks for West Nile virus, a mosquito-borne fever that Britain has so far escaped, louping-ill, a tick-transmitted disease also found in sheep, and other known conditions.

 

A spokesman for the Veterinary Laboratories Agency last night said: "The long-term risk to public health is not known. It is impossible to make an assessment of risk on a single case when the agent responsible is not known. We are now investigating this."

 

Officials were last night unable to say where the affected farm was but said no meat from the cow had been allowed into food.

 

It is understood the brain signature left by the disease looked nothing like BSE but there have been recent suggestions that there is more than one strain of that disease. Ten other cattle which had been in contact with the dead cow have tested negative for louping-ill.

 

Other vets and farmers will soon be alerted to the case via the Veterninary Record journal, typical of the more open attitude demanded by the inquiry into the BSE disaster.

 

BSE was identified by government scientists as a possible new disease at the end of 1986, but despite warnings that this could have "severe repercussions" for humans, information was only given to other senior vets by circular letter the following June and they were barred from telling research institutes about the disease.

 

Embargoes were also put on any information through the Veterinary Record and comparisons with scrapie, a similar disease in sheep, although publication of details became more relaxed later in 1987.

 

The threat of animal-borne diseases that could endanger the public is now taken far more seriously, mainly as a result of the BSE disaster that has so far seen 146 people die or fall incurably ill to the human form of the disease.

 

Only last week, the government published plans to deal with any possible leap of BSE from cattle to sheep. The worst-case senario warned of up to 25m sheep being banned from food, eliminating a year's supply of British lamb, and leaving consumers to rely on imports until flocks could breed replacement animals resistant to the disease.

 

The foot and mouth crisis and threat of Sars, avian flu and other diseases, including West Nile virus, arriving in Britain is also being tackled by huge amounts of time and money being spent on contingency planning.

 

Many infections are already all too common on British farms, including E coli, salmonella and campylobacter, all of which can be extremely dangerous to humans.

 

Some of these are now under firmer control but new risks are continually cropping up. Brucellosis, a contagious disease which causes spontaneous abortion in cattle, had been extinguished in Britain in 1993 but has made a comeback in Scotland and Cornwall. It can pose a danger to people through unpasteurised milk.

 

Twenty farms were hit by botulism last year, five times the average in recent years, and much of the blame is being put down to the illegal or unhygienic use of poultry litter. Food and milk from affected cattle is barred from food but the human disease, though rare, is extremely serious, sometimes causing paralysis and respiratory failure.

 

A person died from an infected in-flight meal in 1987, 26 people were made ill, one of whom died, after toxins infected hazelnut yoghurt, and in 1998 one member of a family died and another fell ill when they brought back infected preserved mushrooms from Italy.

 

The environment department Defra is also about to issue guidance to farmers to control an infection called Johne's disease in cattle.

 

Professor John Hermon-Taylor, of St George's hospital medical school, London , believes it is "inconceivable" that this is not linked to Crohn's disease, an intestinal condition suffered by 100,000 Britons.

 

The government says a link through the bug being transferred in milk "has not been proved nor disproved" but is taking a precautionary stance in seeking to prevent the cattle disease.