Scientists at the Centers for Disease Control and Prevention have confirmed the fourth death in the United States from a rare, fatal brain disorder linked to eating meat from cows with bovine spongiform encephalopathy (BSE), also known as mad cow disease.
The latest case renewed questions from some advocates about the safety of the food supply.
The case involves a patient in Texas who died in May. Lab tests from an autopsy confirmed the patient had variant Creutzfeldt-Jakob disease (vCJD), a deadly disorder first reported in 1996 in the United Kingdom that has killed more than 220 people and prompted the slaughter of millions of cattle. Victims of the degenerative disease, which attacks the nervous system, suffer from depression and dementia before they die.
The CDC said the victim had traveled extensively in Europe and the Middle East and that "supports the likelihood that infection occurred outside the United States." All three previous U.S. deaths were linked to an infection acquired elsewhere—two in the U.K. and one in Saudi Arabia.
"There is no evidence to suggest that other people in the United States have been exposed to variant CJD because of this patient," said CDC spokeswoman Christine Pearson.
Carrie Williams of the Texas State Department of Health Services agreed. "Travel history suggests overseas exposure," she said. The department's website states, "There are no Texas public health concerns or threats associated with this case."
Kathy Simmons, chief veterinarian for the National Cattlemen's Beef Association, an industry group, also cited the infection's likely overseas origins. "There have been no documented cases of vCJD associated directly with beef consumption in the United States," she said in a statement.
She noted that the World Organization for Animal Health last year changed the U.S. status for BSE to negligible, the lowest possible risk, citing safeguards that include an FDA ban on mammalian-derived proteins in livestock feed and random testing of cattle.
The U.S. Department of Agriculture tests the brains of 40,000 dead animals, or less than 0.1 percent of all U.S. cattle, for BSE each year. That's down 90 percent since 2005, when the department announced a limited-time surge to sample high-risk cattle.
Variant CJD is a newer form of Creutzfeldt-Jakob disease, which is not linked to BSE. About 300 cases of CJD are reported each year in the U.S. The median age of those it kills is 68 versus younger than 30 for those infected with vCJD.
Michael Hansen, senior staff scientist at Consumers Union, said the international organization's rating is problematic because it's "based on self-reporting in the U.S. that's not based on anything that's real scientific." He said he is not convinced that government agencies are doing enough to protect the public from tainted food.
The consumer advocate reiterated concerns the group raised in 2012—after the last U.S. case of mad cow disease made headlines—that "safeguards against BSE are not adequate and FDA should take additional steps to protect the health of animals and of the beef-eating public."
BSE was found in a dairy cow during a routine inspection in April 2012 at a rendering plant in California's Central Valley. The cow, which exhibited signs of BSE such as aggression and unsteadiness, never got into the food chain.
Hansen said "huge loopholes" remain in the FDA's feed ban.
"You can take all the blood you want from cows and feed them back to cows because blood and blood products are exempted. So is chicken litter," he said, noting that the nation's largest restaurant buyer of beef, McDonald's, has for years urged that poultry feces be banned from cattle feed.