Study group at risk for human mad cow form

Blood donors and recipients participating in a British study have been warned that they may be at risk for the human form of mad cow disease.

A study of transfusion patients given blood contaminated with the human form of mad cow disease indicated the 24 still alive are at "substantial" risk, scientists said. Recipients were told after a third person from the original group of 66 became infected and died, the BBC said.

The third patient was the first to be diagnosed with variant Creutzfeldt-Jakob disease while alive, researchers said. Two other people died before their illnesses were confirmed. The group's other 39 deaths were unrelated to the disease.

The group is participating in a Medical Research Council trial for a treatment called Prion-1, in which patients were given a drug called quinacrine, the BBC reported. Researchers said prion diseases in humans may have long incubation periods, during which time a carrier could infect others through, among other things, blood transfusions.

Experts told the BBC they think that, based on the cases they've seen so far, infection from a blood transfusion can develop in just six or seven years.

Copyright 2006 by United Press International