WASHINGTON, DC, March 13, 2006 (ENS) - Mad cow disease has been found in the carcass of a cow from an Alabama farm, the third case of the fatal brain wasting disease to be detected in a U.S. animal.
The diseased cow did not enter the human or animal food chains, said U.S.
Department of Agriculture (USDA) Chief Veterinary Medical Officer John
Clifford in a statement today.
"We received a positive result on a Western blot confirmatory test conducted at the USDA laboratories in Ames, Iowa, on samples from an animal that had tested 'inconclusive' on a rapid screening test performed on Friday, March 10," said Clifford.
"The samples were taken from a non-ambulatory animal on a farm in Alabama," Clifford said. "A local private veterinarian euthanized and sampled the animal and sent the samples for further testing, which was conducted at one of our contract diagnostic laboratories at the University of Georgia. The animal was buried on the farm and it did not enter the animal or human food chains."
USDA Chief Veterinary Medical Officer John Clifford (Photo courtesy USDA) Formally known as bovine spongiform encephalopathy (BSE), mad cow disease and its human form, variant Creutzfeldt-Jakob Disease (vCJD), are spread by prions - abnormally shaped proteins that originate as regular components of neurological tissues in animals - they are not cellular organisms or
BSE spreads from one animal to another by consumption of feed that has been contaminated by these proteins, such as meat-and-bone meal, that contains nervous system tissue from an infected animal. The human form of the disease can be transmitted if a human being eats BSE infected meat, and through blood transfusions.
Consuming meat from infected cattle has been linked to the deaths of 154 people worldwide from vCJD.
The USDA Animal and Plant Health Inspection Service (APHIS) is working with Alabama animal health officials to conduct an epidemiological investigation to gather more information on the herd of origin of this animal. The animal had only resided on the most recent farm in Alabama for less than a year.
APHIS officials will be working to locate any offspring and animals born in the same herd within one year of the affected animal, that might also be carrying the disease.
Clifford said, "We will also work with Food and Drug Administration officials to determine any feed history that may be relevant to the
investigation. Experience worldwide has shown us that it is highly unusual to find BSE in more than one animal in a herd or in an affected animal¹s offspring. Nevertheless, all animals of interest will be tested for BSE."
"While epidemiological work to determine the animal¹s precise age is just getting underway and is ongoing, the attending veterinarian has indicated that, based on dentition, it was an older animal, quite possibly upwards of 10 years of age," Clifford said. "This would indicate that this animal would have been born prior to the implementation of the Food and Drug Administration¹s 1997 feed ban.
Alabama cows enjoy a break from the summer heat by standing in the creek. (Photo courtesy USDA) "Older animals are more likely to have been exposed to contaminated feed circulating before the FDA¹s 1997 ban on ruminant-to-ruminant feeding practices, which scientific research has indicated is the most likely route for BSE transmission," Clifford said.
The second U.S. case of BSE was detected in November 2004 in an animal born and raised on a ranch in Texas. About 12 years old at the time of death, it was born prior to the implementation of the 1997 feed ban. The animal was dead upon arrival at the packing plant and was then shipped to a pet food plant where it was sampled for BSE. The pet food plant did not use the animal in its product, and the carcass was destroyed in November 2004.
The discovery of this third BSE infected animal is likely to throw up a roadblock in the U.S. effort to reopen foreign markets to U.S. beef that were closed following the first U.S. detection. In December 2003, BSE was found in a single cow of Canadian origin found on a dairy farm in Washington State.
Agriculture Secretary Mike Johanns met in London with Japanese Minister of Agriculture, Forestry and Fisheries Shoichi Nakagawa on Friday. Japan had partially reopened its market to U.S. beef products, but decided to reinstate its import ban in January because of the first shipment of U.S. veal which contained intact vertebral column and veal offal - materials classed as of "high risk" for transmission of BSE.
A February USDA report attributed the mistake to the two meat packing plants that contributed to the shipment and to USDA inspectors.
Secretary Johanns imposed additional mandatory training for Food Safety and Inspection Service inspectors to ensure they do not make similar mistakes in the future.
But some livestock growers say the discovery of another BSE infected animal on a U.S. farm shows the need for a stronger feed ban.
From his office in Billings, Montana, Bill Bullard, CEO of R-CALF USA, the Ranchers-Cattlemen Action Legal Fund, United Stockgrowers of America, told ENS, "The U.S. needs to erect substantial barriers to this disease. The USDA needs to strengthen the feed ban to ensure this disease cannot recycle within our feed system."
R-CALF USA represents some 18,000 U.S. cattle producers on domestic and international trade and marketing issues. "The government should allow private packers to test for BSE," Bullard said.
Normally vegetarian, if cattle are fed nervous system tissue from other ruminant animals, the infectious prions that cause BSE can be spread from animal to animal. (Photo courtesy USDA) The U.S. enhanced surveillance program for mad cow disease that began in June 2004 is coming to an end, Clifford said. "Since June 2004, all sectors of the cattle industry have cooperated in this program by submitting samples from more than 650,000 animals from the highest risk populations and more than 20,000 from clinically normal, older animals, as part our enhanced BSE surveillance program," he said.
Only two of these highest risk animals have tested positive for the disease as part of the enhanced surveillance program, Clifford said.
The enhanced surveillance program has cost about $1 million a week, and on average, nearly 1,000 high risk cattle a day are tested for BSE.
Bullard says the United States should continue "a robust surveillance program to see how prevalent the is disease is in our herd, and call upon our trading partners, especially Canada, to do the same."
Canada has detected three cases of BSE since May 2003. But unlike the United States, Bullard points out, Canada has detected BSE in younger animals and animals born more than three years after the 1997 feed ban. "This provides scientific evidence that BSE has been recycling in the Canadian feed system as late as 2000," he said.
Clifford told reporters on a conference call today that APHIS would base maintenance surveillance testing on international guidelines, although no program has been detailed yet.
"Though the nature and extent of maintenance surveillance has not yet been finalized," Clifford said, "the incidence of BSE in this country remains extremely low and our interlocking safeguards are working to protect both human and animal health and we remain very confident in the safety of U.S. beef."
Wenonah Hauter, executive director of Food & Water Watch, said the United States needs to put a mandatory BSE reporting program in place and also to continue its enhanced surveillance program.
"We applaud the farmer who did the right thing by turning over the sick cow in question to a veterinarian for testing," Hauter said. "But this is still a voluntary system that must be made mandatory for the sake of public health. Without a mandatory reporting system, who knows what else is out there?"
"We urge USDA to continue its heightened surveillance program and to fight for more money in its 2007 budget for continued testing. As it currently stands, the fiscal budget for 2007 only provides for 40,000 tests. This is insufficient," said Hauter. "Mad cow disease will not go away on its own.
The government must admit there's a problem and take the necessary steps to fix the problems and protect all consumers."