Idaho probes outbreak of Creutzfeldt-Jakob disease

Idaho officials on Friday confirmed one case of naturally occurring Creutzfeldt-Jakob disease (CJD) and are investigating five other suspected cases, but said none are believed to be caused by eating infected animals.

CJD is a rare brain-wasting disease in humans that usually affects older people in their 60s or 70s. It is not the same as the human form of mad cow disease, which is known as variant Creutzfeldt-Jakob disease and is linked to eating beef from infected cattle.

Tom Shanahan, a spokesman for the Idaho Department of Health and Welfare, said five of the cases involve people who have already died, lived in neighboring counties and were over the age of 60. The sixth case centered on a man, also over the age of 60, who lived 90 miles away and was still alive.

"It is the naturally occurring type of CJD," Shanahan said. "It is not variant."

Naturally occurring CJD is found at a rate of about one case per 1 million population annually, according to the U.S. Centers for Disease Control. Yet in a state with only 1.4 million people the fact that Idaho has so many suspected cases of the rare disease has sparked concern.

Creutzfeldt-Jakob disease Definition
Creutzfeldt-Jakob disease is a disorder involving rapid decrease of mental function and movement. These are abnormalities believed to be caused by damage done to the brain by a protein called a prion. This protein folds abnormally, and seems to encourage other proteins to become similarly misshapen, affecting their ability to function.
Shanahan said researchers at Case Western Reserve confirmed that brain tissue from one woman showed CJD caused her death and that the state was waiting for results from two other tests. All the deaths occurred this year, beginning in February, he said.

"We actually are real concerned because we have never had more than three cases in a year and they are in one geographic area," Shanahan said.

The sixth suspected case involves an elderly man who has not yet died, he said. The disease cannot be confirmed until a brain sample is collected and analyzed after death.

Investigators so far have not been able to pinpoint anything that may have caused the disease and are looking at such factors as the victims' diets.

The Centers for Disease Control in Atlanta is monitoring the Idaho situation but has not been asked by the state to participate in a formal probe, said agency spokesman David Daigle.

The U.S. meat industry also said the outbreak of cases had no connection to mad cow disease or bovine spongiform encephalopathy (BSE) and reassured consumers that meat was safe to eat.