Researchers may have found a way to block the spread of the human form of mad cow disease through blood transfusions by filtering the blood first, a new study shows.

Earlier research has raised the possibility that blood transfusions may be the easiest way for humans to get the disease—easier than eating meat from cows infected with mad cow disease.

And currently, there is no way to test blood for the human form of mad cow, known as variant Creutzfeldt-Jakob Disease or vCJD—a fatal, neurodegenerative disease that may incubate for years with no apparent symptoms.

In the U.K., three people have died from vCJD after receiving infected blood donations.

But researchers may have discovered a way to remove vCJD by filtering blood from infected animals.

"For these disease agents, removal may be our best and perhaps our only option," said Dr. Robert Rohwer of the University of Maryland in Baltimore, in a release.

Creutzfeldt-Jakob Disease, BSE in cows and scrapie in sheep are all thought to be caused by prions, an infectious agent made of protein that is believed to be the cause of certain brain diseases, including mad cow.

In the experiment, the researchers first filtered blood from infected animals to remove white blood cells. They then used a specially developed resin to remove prions from the blood. That blood was then given to the hamsters.

None of the 96 rodents given blood treated with the resin became infected. Meanwhile, of the 100 hamsters given untreated blood, 99 were infected, the researchers said in this week's issue of The Lancet.

The specially designed resin helps block out pathogenic prions and viruses from blood.

Since 1996, there have been 199 cases worldwide of vCJD, 164 of them in Britain, according to the study. Cases have also been reported in France, Italy, Ireland, the Netherlands, Canada, Japan and the United States.

"Until these technologies can be clinically and operationally assessed, the best protection against the uncertain risk of transfusion-associated prion disease remains in ensuring that blood products are used only if needed," said Marc Turner of the Edinburgh Blood Transfusion Centre in a journal commentary

He said that, "the uncertainties surrounding potential risks [must be] communicated effectively to patients and to the public at large."