A technique for identifying abnormal proteins in hamsters may lead to the first human test for the fatal brain-wasting illness caused by mad cow disease, researchers said.
Blood tests in hamsters with scrapie, a disease related to mad cow, or bovine spongiform encephalopathy, were able to detect signs of infection before symptoms appear, according to a study in today's issue of the journal Science.
The study is a step toward diagnosing the human version, known as variant Creutzfeldt-Jakob disease, early enough to prevent its spread, according to the study.
``This can prevent further transmission of the disease,'' said Claudio Soto, professor of neurology at the University of Texas Medical Branch in Galveston, a co-author of the study.
Discovering the disease in its early stages is important because of the ``long and silent period from the onset'' until symptoms appear, according to the report.
``Incubation can last several decades, in some cases up to 40 years, so it is possible that people in the U.K. and Europe are infected and are not clinically sick,'' he said, referring to where the disease was first reported.
Researchers inoculated 46 hamsters with scrapie and used a laboratory process that amplifies the quantity of abnormal prion proteins in the blood to a measurable amount. Until now, measurable levels of the protein could only be detected in the brain and some lymph tissue late in the course of the disease, researchers said.
The highest positive results came 40 days after infection, about 74 days before symptoms appeared, according to the study. The disease wasn't detectable in the blood after 80 days, Soto said.
``This is a very unique infectious agent,'' Soto said.
People get the disease by consuming meat from cows that are infected by feed containing contaminated tissue from other animals. There is concern that there may be people who are unaware they have the disease, Soto said.
Soto said that a wave or outbreak of the disease could be ``very large, because potentially infected people are walking around and donating blood.''
The technology outlined today could detect the prions or disease in blood banks and hospitals, Soto said.
To the reporter on this story: Mario Parker in Chicago at [email protected]