“We know the possibility exists that we will have confirmation of a positive case in this country (native-born),” says Ron DeHaven administrator of USDA's Animal and Plant Health Inspection Service (APHIS). He was talking in mid-June about the potential results of USDA's expanded surveillance system for bovine spongiform encephalopathy (BSE), a single, intensive effort to take a BSE snapshot of the nation's cattle industry in the name of establishing a baseline for the existence and prevalence of BSE in light of December's discovery.
In fact, by June 25 USDA was reporting its first inconclusive BSE test since the expanded surveillance effort began. What that boils down to is that a sample tested positive via a rapid screening test for BSE. These rapid tests are known to produce false positives. Consequently, USDA will call any samples that test positive for BSE with a rapid screening test inconclusive until the sample in question undergoes an immunohistochemistry (IHC) test—considered the gold standard of BSE tests. If the sample comes out as negative with the IHC test, then it is negative; the results of the rapid screening test produced a false positive.
On the other hand, if the sample currently in question tests positive via the immunohistochemistry test (results at press time were expected before July 4), and is confirmed by an international reference laboratory—if USDA chooses to add that extra step—then the U.S. will play host to its second case of BSE within six months. If that's the case, though, it will probably be some time before the suspect animal can be defined as native-born or import.
"The inconclusive result does not mean we have found another case of BSE in this country. Inconclusive results are a normal component of most screening tests, which are designed to be extremely sensitive so they will detect any sample that could possibly be positive,” explains John Clifford, APHIS Deputy Administrator. He emphasizes, "This animal did not enter the human food chain nor the feed chain.”
Just before trading opened June 28, the markets—especially near-term—were bearish on the news, but as of that time there was no limit-down freefall.
The Cost of Proof
While this most recent BSE gut-churner will likely have some folks questioning USDA's expanded program, the fact is ever since the BSE case was discovered in December, the nation's risk level—albeit so low as to be almost non-existent, according to the science—is an unknown.
“Surveillance is intended to find out if we have the disease and if so at what prevalence rate. We need that to tailor our BSE programs, but we also need it for our trading partners,” says DeHaven. He notes that the international community's lack of faith in the magnitude of previous U.S. BSE testing continues to be a stumbling block in resuming exports of U.S. beef. That's despite the fact that these previous testing levels—approximately 20,000 head of high risk animals each of the past two years—exceeds international recommendations by 47 times.
In other words, situations like the recent inconclusive test demand a heavy dose of perspective.
“No matter how the confirmatory testing comes back, USDA remains confident in the safety of the U.S. beef supply,” says Clifford. “Again, this animal did not enter the human food chain or feed chain. Our ban on specified risk materials from the human food chain, provides the protection to public health, should another case of BSE ever be detected in the United States. By banning specified risk materials (SRMs)—skull, brain, trigeminal ganglia, eyes, portions of the vertebral column, spinal cord and dorsal root ganglia from cattle aged 30 months or older, and tonsils and the small intestine of cattle of all ages—USDA ensures all SRMs, or those materials most likely to contain the BSE agent, are removed from a suspect animal.”
Clifford also reiterates the fact that these inconclusive tests are an expected part of the process. “Screening tests are often used in both human and animal health. They are designed to cast a very wide net in order to catch any possible patient that may have the condition, many of which will end up negative during further testing - glucose testing for diabetes is a good example. This is the type of screening test we are using for BSE surveillance testing,” says Clifford. "And some subset of these animals may even turn out to be positive for BSE. While none of us wants to see that happen, that is not unexpected either. Our surveillance program is designed to test as many animals as we can in the populations that are considered to be at high risk for BSE. If we test 268,000 animals in the next 12 to 18 months, which we are fairly well on track to do, we will be able to find the disease if it occurs in as few as 1 in 10 million adult cattle with a 99 percent confidence level. In other words, our program could detect BSE even if there were only five positive animals in the target population in the entire country.”
Given the fact that some of the BSE safeguards added since December—including the prohibition of non-ambulatory cattle being harvested at federally inspected facilities—have reduced USDA's ability to test high-risk cattle at harvest facilities, achieving the goals of the expanded BSE surveillance program will require plenty of producer cooperation.
Specifically, USDA is requesting anyone with cattle that fit the high-risk profile to report them to USDA so that it can make arrangements to collect samples. High-risk categories include: non-ambulatory cattle; cattle exhibiting signs of central nervous system disorder; cattle exhibiting other signs that may be associated with BSE, such as emaciation or injury; and dead cattle. USDA will also sample all cattle condemned during ante-mortem inspection by the Food Safety and Inspection Service.
In return, DeHaven says USDA will pay for removal and disposal of these cattle. USDA will also compensate producers for any cattle taken as the result of finding an animal infected with BSE.
To report high-risk cattle, use this toll-free number: 1-866-536-7593. That number will route you to the USDA Area Veterinarian in Charge nearest to you, who can offer instructions on how to proceed.
Again, testing more high-risk cattle means there is more opportunity to find the disease if it exists, which is the point of the exercise, unsettling as that is to some.
“If we find a case of BSE and it turns out to be native-born it shouldn't come as a shock to anyone. If it happens, it should be, so what?,” says DeHaven. “In terms of public health, by removing Specific Risk Materials from the food supply we have already done the single most important thing we can do to protect public health. With the ruminant-to-ruminant feeding ban we have already done the single most important thing we can to prevent the transmission of the disease from one animal to another if it exists.”
While some might be reluctant to take such a bet on the American consumer, the odds would be in their favor based on reaction to this point.
“I think consumer reaction in the United States has been fundamentally different than in the rest of the world,” says DeHaven. Specifically, other than Canadian consumers reacting to the discovery of BSE there much like consumers here—beef demand didn't lose any ground—consumers in other countries panicked when the disease was found in their domestic supplies.
While there is no discounting the tragedy of the people who die at the hands of new variant Creutzfeldt-Jakob Disease (nvCJD)—still tenuously tied but never proven to stem from people consuming beef infected with BSE—the fact is that a disproportionate amount of money is going into BSE defense. In sum, DeHaven reckons 18-22 people die annually from nvCJD. By comparison, hundreds of thousands of people around the world die each year from food borne diseases such as salmonella and E. coli 0157:H7. Yet it is BSE that is getting the lion's share of attention.
“I'm not minimizing the effects of BSE, but it is far more an economic and emotional disease than it is a threat to public health,” says DeHaven.
With that in mind, all producers have a vested interest in reporting cattle that qualify for the expanded surveillance program in the name of defining BSE risk as quickly as possible in order to mitigate the price risk of not knowing as fast as possible.