This suggested that BSE could be present in US cattle for the first time. Although the link between CJD and BSE has never been proven, cattle and grain futures plunged on fears that consumers would avoid US beef.
Last year a UK government panel linked CJD with eating BSE-infected beef.
There was further evidence this week that fear of mad cow disease is no longer a European problem but is spreading across the globe. Japan's largest supermarket chain, Daiei Inc, said on Friday that consumer concern about BSE had affected food sales last year.
Cattle futures in Chicago fell 2.2 per cent on Wednesday when the news of the death was released. Prices steadied by the end of the week but traders remain nervous.
"The report of the Indiana death is bad publicity for beef," said Joe Kropf, a livestock analyst in Kansas.
The Indiana state health department is now awaiting the autopsy report on the farmer, Joseph Gabor, which it expects in about a week, a spokeswoman for the department said. Department officials will then determine whether to investigate the case further.
About 300 Americans, usually older people, die of CJD each year according to the Center for Disease Control in Atlanta. The farmer's death from CJD does not in itself establish a "mad cow" link.
Meantime, the Food and Drug Administration in Washington has speeded up its deliberations on how to prevent the disease hurting US cattle herds. It announced on Friday that it is seeking comment on a proposal to ban animal protein in the feed of cattle and other cud-chewing animals.
The plan, in the form of a draft rule that is open for comment until 28 April, builds on a January proposal to ban the feeding of protein derived from cattle, sheep and other animals with four-chambered stomachs, a class known as ruminants. The new proposal expands the ban to all mammals, excluding swine.
"We've broadened the prohibition and we are committed to moving forward with the final rule quickly," said FDA spokesman Lawrence Bachorik. It could still be a few months away, however, as it has to be reviewed by the Department of Health and Human Services and the Office of Management and Budget.Reuse content