Consumers Union has asked the U.S. government to come clean about its testing program for mad cow disease, in the wake of the discovery last week that a third animal has tested positive in a preliminary examination for bovine spongiform encephalopathy. "This animal poses no threat to our food supply because it did not enter the human food or animal feed chains," said USDA Chief Veterinary Medical Officer John Clifford in a public statement. But that single episode is not what concerns Consumers Union, a nonprofit consumer advocacy group based in Yonkers, N.Y. "The government keeps telling Americans that they can trust that their beef is safe from mad cow," said Michael Hansen, Ph.D., senior scientist with CU. "Yet, since the agency has so far failed to publicly disclose any information whatsoever about the details of the program, it makes us wonder how meaningful their search for the disease is at all."
In a letter to USDA Secretary Mike Johanns, Hansen wrote, "We are concerned about the meaningfulness, credibility and lack of transparency of the expanded BSE Surveillance Program." Hansen cited the fear that "sampled brains may not be a proper geographical sample of the high-risk population, and that the highest-risk brains may not be included." He also stressed that the voluntary nature of the program rendered it invalid.
Specifically, Hansen noted that animals that show neurological problems are first tested for rabies. If the rabies test is negative, the animals should be highly suspect for BSE infection and summarily tested. "Only a small percentage [16 percent] of rabies-suspect, rabies-negative cattle were actually tested for BSE" between 1990 and 2004, according to a November 2004 report that Hansen cited from the Office of Inspector General on the first phase of the BSE surveillance program. USDA has not released any data from the expanded program (begun June 1, 2004) regarding the number of rabies-negative cattle tested for BSE. In addition, among 162 cattle that were destroyed because of central nervous system symptoms, only 24 percent were tested for BSE, according to the OIG report. CU also noted that not all aged dairy cows—another high-risk group—were tested. CU has asked the government to release data on how many high-risk animals have been tested for BSE under the expanded program.
"As of July 1, APHIS didn't have any plan. They said that all of [the rabies-negative cattle] should be tested, but they also said that when the program started in 1990," said Hansen. APHIS is the Animal and Plant Health Inspection Service of the USDA. "If they couldn't do it in the first 14 years, how could they [now] turn it around so quickly?"
A USDA spokesman said the agency tests high-risk cattle in large numbers. "We estimated the cattle population for high risk to be 450,000 to 460,000 and we've tested more than 420,000, and we're still testing," he said. "We're not doing 100 percent testing—we never said we were, and it has nothing to do with food-safety protocols." Those regimens include a ban on downer animals, removal of specific risk materials and the prohibition of certain slaughter techniques.
Another problem that the OIG observed—and that Hansen noted in his letter to Johanns—is that when cows die on the farm, producers may be reluctant to submit tissue samples for testing. If it tests positive, he said, the rest of the herd may be slaughtered. Others, however, have "the motivation to mischaracterize low risk carcasses as 'high risk' since only the latter may qualify for reimbursement," the OIG report said. Producers get $100 for each brain they submit for testing, regardless of the results. "These inherent problems can lead to an understatement of the projected maximum BSE prevalence rates for truly high-risk cattle and a reduced chance of detecting BSE, if it exists," the report concluded.
"We've said from the very beginning that there were probably more cases out there," the USDA spokesman said, "but the food-safety protocols are there to protect the food supply. ... Even if there were no testing, the food-safety protocols would still be there." He noted that most of the animals slaughtered in the United States are younger than 20 months. "The younger the animal, the more likely you?ll get false negatives. ... Having something stamped 'BSE-free' doesn't really mean anything."
Hansen said that while he has not received any formal response from Johanns, the OIG would be looking into the concerns CU outlined, with a new report coming out perhaps as early as this fall.