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One Reason the Japs don't trust the US.
New "Gold Standard" test for BSE?
By Richard Hanson
DTN Special Correspondent
TOKYO (DTN)--This is what dining out on beef, post-December 23, may be like unless someone figures out how to test properly for bovine spongiform encephalopathy, widely known as mad cow disease:
The chef is about to flame a juicy cut of grain-fed U.S. prime sirloin beef at your favorite Teppan-yaki place.
The chef says: "This meat is safe."
Hungry customer, bib in place, asks: "How do you know?"
Chef: "Well, it passed America's Gold Standard test--it's a big 'negative' for that mad cow disease."
Customer: "Great, no mad cow."
Chef: "Yeah, it probably doesn't matter that it was 'positive'--you know, a little gamy--in that Western Blotting test, the one they use in Japan. How do you want your meat done? Rare?"
Customer: "Uh, how's the chicken today?"
Gold Standard and Western Blotting--both scientific methods for detecting and confirming the deadly cattle disease bovine spongiform encephalopathy (BSE)--have become buzz words in a delicate stand-off between the U.S. Department of Agriculture and Japanese farm officials over which tests are really going to tell the truth about which animals have mad cow disease.
U.S. officials have questioned recent tests done by Japan, and favored by Japanese scientists, called Western Blotting, that have produced positive (meaning the animal has BSE) test results in the latest two cases of the disease in the autumn last year. These were positives on cattle much younger than usual (21 and 23 months old), which shocked the Japanese public and caused confusion in the scientific community.
What puzzled everyone is that when these same two cases were tested using the test USDA and others consider the Gold Standard, the results were negative--no BSE. This test is called immunohistochemical screening. A lab uses a tissue sample that is treated with a stain carrying antibodies that cling to the abnormal prions that cause the disease. A pathologist then looks for an accumulation of stained antibodies in the sample.
After America's first mad cow case was revealed on Dec. 23, Japan and virtually ever other major beef-importing country banned U.S. beef and beef-related products. Then Japan shocked the U.S. by signaling that lifting the import ban will require meeting the same requirement to assure consumer safety as Japan has--testing all cows for BSE.
That, in effect, closed America's largest beef export market.
In Japan, the test-all policy, started soon after the September 2001 announcement of Japan's first BSE case, was originally thought to be overkill by Japanese experts. It involves testing each year about 1.2 million cows that are sent to the slaughterhouse.
"At first, we proposed testing only 900,000 cattle," recalls Professor Takashi Onodera, a molecular immunologist at the University of Tokyo who heads a BSE governmental advisory panel. "The politicians in the (ruling) Liberal Democratic Party pushed for testing all. Since it only meant another 300,000 cows, we agreed."
Professor Onodera is one of a number of scientists who say the test results of Japan's last two mad cow cases--numbers eight and nine--may mean that they have found a "a new form of the prion causing the disease." In essence, the Japanese scientists think there may be different strains of BSE, with some showing up in younger animals.
The test that found BSE in Japan's last two cases is called Western Blotting, and it is used in some European countries as well. Among its advantages over the Gold Standard test are speed--results in hours instead of weeks--and price (less than a fourth the Gold Standard test). The lower price allows many more animals to be tested without increasing the cost. In Western Blotting a brain-tissue specimen is liquefied and then treated with a special mixture that degrades normal prions, leaving only the BSE-specific abnormal prions in the specimen.
Onodera and some other scientists believe Western Blotting should be the new "gold standard." USDA is not convinced.
At a press conference, USDA chief veterinarian Ronald Dehaven, questioned the Japanese test results for the last two BSE cases. "They (the Japanese) have reported them as positive, and yet both of those animals were negative on the immuno-histo chemistry test, the test that is internationally recognized as the gold standard test. They have been positive on other tests," he said, referring to the Western Blotting tests. "At this point in time there has not been an opportunity for international corroboration on the exact findings as it relates to those animals, and some suggestion by the Japanese government that perhaps they have a different strain of BSE. Again, all of that is chatter within the intellectual community. No definitive determination made at this point. And certainly it would be premature to modify any national program based on those two animals."
Japan's Ministry of Agriculture, Forestry and Fisheries and Ministry of Health, Labor and Welfare stands by the conclusions reached last November by a specially appointed study panel that the cases number eight and nine are BSE.
DTN has learned that other tests--also immunohistochemical screening--of the last two BSE cases performed by an independent lab also returned negative for BSE. In December, the Ministry of Health quietly, after diplomatic requests, sent tissue slide samples from the cattle to the UK's Veterinary Laboratories, located in Weybrook. This was done under sharp pressure from other BSE-infected countries before America's BSE case was found. Weybrook confirmed Japan's first BSE case, as well as USDA's first case last Dec. 23.
The cost of testing American cattle as young as 20 months, which U.S. consumer groups are demanding, would be significant. John Harrington, DTN's livestock analyst, estimates that 70 percent of the 35 million cattle slaughtered in the U.S. last year would meet the "as young as 20 month" criterion consumer groups are proposing. The cost of the "gold standard" test has been estimated at $200, while some of the faster tests are said to cost in the $30 to $50 range.
Onodera is waiting for the results of more extensive experiments being conducted in Japan by two government laboratories--The National Institute of Infectious Diseases and the National Institute of Animal Health. They have started scientific tests by infecting "transgenic" mice with the suspect BSE tissue, but the results won't be available until later this year at the earliest.
In the meantime, the world just has to wait for further developments. BSE has proven to be a maddeningly fickle pathogen and it does not grow very rapidly even in laboratory conditions. In the eyes of many Japanese consumers, Japan's test-all policy is proving its worth, at least in easing consumer worries about eating beef. What worries scientists is that Japan is just beginning to see the results of having fed cattle with meat and bone meal--the chief suspect in spreading BSE. Japan banned it only after the first case was found in September 2001. The government is still trying to locate and destroy stockpiles of the feed.
It is unclear just what the U.S. will propose in mid-January when a senior delegation from the USDA arrives for talks with their Japanese counterparts. But on the critical question of testing methods, the governments are very far apart.
Onodera has his own test: "Will you eat meat from a cow that tests negative on one test and positive on the other?"
One Reason the Japs don't trust the US.
New "Gold Standard" test for BSE?
By Richard Hanson
DTN Special Correspondent
TOKYO (DTN)--This is what dining out on beef, post-December 23, may be like unless someone figures out how to test properly for bovine spongiform encephalopathy, widely known as mad cow disease:
The chef is about to flame a juicy cut of grain-fed U.S. prime sirloin beef at your favorite Teppan-yaki place.
The chef says: "This meat is safe."
Hungry customer, bib in place, asks: "How do you know?"
Chef: "Well, it passed America's Gold Standard test--it's a big 'negative' for that mad cow disease."
Customer: "Great, no mad cow."
Chef: "Yeah, it probably doesn't matter that it was 'positive'--you know, a little gamy--in that Western Blotting test, the one they use in Japan. How do you want your meat done? Rare?"
Customer: "Uh, how's the chicken today?"
Gold Standard and Western Blotting--both scientific methods for detecting and confirming the deadly cattle disease bovine spongiform encephalopathy (BSE)--have become buzz words in a delicate stand-off between the U.S. Department of Agriculture and Japanese farm officials over which tests are really going to tell the truth about which animals have mad cow disease.
U.S. officials have questioned recent tests done by Japan, and favored by Japanese scientists, called Western Blotting, that have produced positive (meaning the animal has BSE) test results in the latest two cases of the disease in the autumn last year. These were positives on cattle much younger than usual (21 and 23 months old), which shocked the Japanese public and caused confusion in the scientific community.
What puzzled everyone is that when these same two cases were tested using the test USDA and others consider the Gold Standard, the results were negative--no BSE. This test is called immunohistochemical screening. A lab uses a tissue sample that is treated with a stain carrying antibodies that cling to the abnormal prions that cause the disease. A pathologist then looks for an accumulation of stained antibodies in the sample.
After America's first mad cow case was revealed on Dec. 23, Japan and virtually ever other major beef-importing country banned U.S. beef and beef-related products. Then Japan shocked the U.S. by signaling that lifting the import ban will require meeting the same requirement to assure consumer safety as Japan has--testing all cows for BSE.
That, in effect, closed America's largest beef export market.
In Japan, the test-all policy, started soon after the September 2001 announcement of Japan's first BSE case, was originally thought to be overkill by Japanese experts. It involves testing each year about 1.2 million cows that are sent to the slaughterhouse.
"At first, we proposed testing only 900,000 cattle," recalls Professor Takashi Onodera, a molecular immunologist at the University of Tokyo who heads a BSE governmental advisory panel. "The politicians in the (ruling) Liberal Democratic Party pushed for testing all. Since it only meant another 300,000 cows, we agreed."
Professor Onodera is one of a number of scientists who say the test results of Japan's last two mad cow cases--numbers eight and nine--may mean that they have found a "a new form of the prion causing the disease." In essence, the Japanese scientists think there may be different strains of BSE, with some showing up in younger animals.
The test that found BSE in Japan's last two cases is called Western Blotting, and it is used in some European countries as well. Among its advantages over the Gold Standard test are speed--results in hours instead of weeks--and price (less than a fourth the Gold Standard test). The lower price allows many more animals to be tested without increasing the cost. In Western Blotting a brain-tissue specimen is liquefied and then treated with a special mixture that degrades normal prions, leaving only the BSE-specific abnormal prions in the specimen.
Onodera and some other scientists believe Western Blotting should be the new "gold standard." USDA is not convinced.
At a press conference, USDA chief veterinarian Ronald Dehaven, questioned the Japanese test results for the last two BSE cases. "They (the Japanese) have reported them as positive, and yet both of those animals were negative on the immuno-histo chemistry test, the test that is internationally recognized as the gold standard test. They have been positive on other tests," he said, referring to the Western Blotting tests. "At this point in time there has not been an opportunity for international corroboration on the exact findings as it relates to those animals, and some suggestion by the Japanese government that perhaps they have a different strain of BSE. Again, all of that is chatter within the intellectual community. No definitive determination made at this point. And certainly it would be premature to modify any national program based on those two animals."
Japan's Ministry of Agriculture, Forestry and Fisheries and Ministry of Health, Labor and Welfare stands by the conclusions reached last November by a specially appointed study panel that the cases number eight and nine are BSE.
DTN has learned that other tests--also immunohistochemical screening--of the last two BSE cases performed by an independent lab also returned negative for BSE. In December, the Ministry of Health quietly, after diplomatic requests, sent tissue slide samples from the cattle to the UK's Veterinary Laboratories, located in Weybrook. This was done under sharp pressure from other BSE-infected countries before America's BSE case was found. Weybrook confirmed Japan's first BSE case, as well as USDA's first case last Dec. 23.
The cost of testing American cattle as young as 20 months, which U.S. consumer groups are demanding, would be significant. John Harrington, DTN's livestock analyst, estimates that 70 percent of the 35 million cattle slaughtered in the U.S. last year would meet the "as young as 20 month" criterion consumer groups are proposing. The cost of the "gold standard" test has been estimated at $200, while some of the faster tests are said to cost in the $30 to $50 range.
Onodera is waiting for the results of more extensive experiments being conducted in Japan by two government laboratories--The National Institute of Infectious Diseases and the National Institute of Animal Health. They have started scientific tests by infecting "transgenic" mice with the suspect BSE tissue, but the results won't be available until later this year at the earliest.
In the meantime, the world just has to wait for further developments. BSE has proven to be a maddeningly fickle pathogen and it does not grow very rapidly even in laboratory conditions. In the eyes of many Japanese consumers, Japan's test-all policy is proving its worth, at least in easing consumer worries about eating beef. What worries scientists is that Japan is just beginning to see the results of having fed cattle with meat and bone meal--the chief suspect in spreading BSE. Japan banned it only after the first case was found in September 2001. The government is still trying to locate and destroy stockpiles of the feed.
It is unclear just what the U.S. will propose in mid-January when a senior delegation from the USDA arrives for talks with their Japanese counterparts. But on the critical question of testing methods, the governments are very far apart.
Onodera has his own test: "Will you eat meat from a cow that tests negative on one test and positive on the other?"
