Blood test may help to identify mad cow disease

U.S. scientists earlier could not diagnose mad cow disease and its human version. Now it has become possible to do a useful blood test.

Transfusions can spread the disease among people, but there is no practical test to detect it. That is why blood donors are carefully screened to weed out people who have lived in or visited certain areas where they might have become infected.

Until now, dissecting the brains of victims has offered the only way to detect the brain-wasting disease in humans.

Both the animal and human forms of the disease are caused by agents called prions. Researchers led by neurology professor Claudio Soto at the University of Texas Medical Branch at Galveston report they have developed a method of multiplying the number of prions in a blood sample so that a blood test can then detect them, the AP says.

Such a test could help prevent the spread of the disease through transfusions and could detect the illness in people or animals before it can be spread to others.

The findings, to appear in the September issue of the journal Nature Medicine, were released online Sunday.

The first known prion disease was scrapie, which has infected sheep for many years. In the 1980s, Britain had an outbreak of bovine spongiform encephalopathy, better known as mad cow disease, which spread to Europe and other areas. Two cows have been found with the illness in the United States.

The human form of the illness is called variant Creutzfeldt-Jakob disease and is thought to have originated from eating infected beef.

The extent of the human form of the disease is not known, but it has killed about 180 people worldwide. Symptoms can take years to develop.