By By Don A. Franco, D.V.M.
President, Center for Bio-security, Food Safety, and Public Health
Editor’s Note – The following is a review of the protective measures the United States has put in place over the past 17 years to prevent the introduction of bovine spongiform encephalopathy in the country.
1986: Within 10 days of the confirmatory diagnosis of bovine spongiform encephalopathy (BSE) in the United Kingdom in November 1986, the disease in the United States became a legally reported disease under Title 9, Code of Federal Regulations, Parts 71 and 161, making the United States the first country in the world to take immediate action by recognizing the potential threat to animal health.
1988: The U.S. Department of Agriculture (USDA), serving as the organizing facilitator, established a BSE standing committee of subject matter experts from government agencies, academia, the research community, and industry representatives to regularly review the published literature, discuss the science, invite experts, examine the prevailing epidemiology in the United Kingdom, and further suggest appropriate regulatory measures to preclude the likely entrance of the infectious agent of BSE into the country.
In essence, strategies were being developed in the United States to be proactive in the protection of animal health early in the process while U.S. scientists at the National Institute of Health and the Centers for Disease Control started to look at the public health inferences and began early collaboration/communication with British researchers. This is the added value of a technologically advanced society. The United States had the resources to act and, contrary to the critics, the country acted early and responsibly.
1989: The importation of all ruminants, bovine semen, embryos, and meat and bone meal from the United Kingdom was banned based on the evolving epidemiology of potential risk factors.
The United States established policies for the submission of tissues from BSE “suspect” cases for laboratory diagnosis that include field cases of cattle exhibiting signs of neurological disease, cattle condemned at slaughter for neurological reasons, rabies-negative cattle submitted to public health laboratories, and aged cattle that are not ambulatory at slaughter (“downer” cattle).
1990: USDA began a BSE educational outreach program educating veterinary practitioners, veterinary laboratory diagnosticians, industry, and producers about the pathology and clinical manifestations of the disease.
An active BSE surveillance program was established including histo-pathological examinations of brains of high-risk cattle, and a trace back program of cattle imported from the United Kingdom was initiated.
The Food and Drug Administration (FDA) established a BSE task force with initial discussions of product inventories and guidance letters to the regulated industry on products of bovine origin.
1991: USDA conducted a BSE risk analysis and en-acted formal regulations to prohibit the importation of most ruminant products from any country known to have BSE.
1992: An FDA Import Bulletin on September 1st alerted field units to imports from BSE countries of animal by-products and regulated products with animal by-product ingredients.
1993: USDA did an extensive re-assessment and update of the 1991 risk analysis to address emerging epidemiologic inferences.
1994: USDA expanded its diagnostic testing policy to include supplemental tests for abnormal prion proteins that are indicative of the infectious agent of BSE – immunohistochemistry.
1996: USDA did another analysis of BSE to reflect currency and reviewed the initial findings of analyses done in 1991 and 1993 to determine the degree of existing risk.
USDA and the U.S. Public Health Service issued a press release supporting voluntary industry efforts to keep the United States free of BSE. This was based on a March 20, 1996, British government announcement of 10 cases of a previously unrecognized form of Creutzfeldt-Jakob disease and a possible relationship to BSE.
The FDA advanced notice of proposed rulemaking on May 14th solicited comments on use of protein derived from ruminants in ruminant feed.
1997: USDA prohibited importation of live animals and most ruminant products from throughout Europe.
The FDA’s Center for Veterinary Medicine published a final rule – Substances Prohibited from Use in Animal Food or Feed: Animal Proteins Prohibited in Ruminant Feed. The rule, Title 21, Code of Federal Regulations, Part 589, became effective August 4, 1997. This is the “ruminant-to-ruminant” feed ban.
1998: USDA entered into a cooperative agreement with Harvard University to analyze and evaluate the effectiveness of the department’s prevention and control strategies and determine whether the current policies instituted are adequate to preclude the potential for the infectious agent of BSE to be transmitted through feed to cattle and the likelihood of a disease outbreak that could ultimately affect human health.
1999-2000: USDA enhanced the surveillance program of non-ambulatory cattle (“downers”) and increased the sampling regimen of brain submissions that was five times over the recommended criterion of the Office International des Epizooties.
2000: The USDA’s Animal and Plant Health Inspection Service prohibited the imports of rendered animal proteins from Europe.
The General Accounting Office (GAO) published a comprehensive report, Food Safety (September 2000 – GAO/RCED-00-255): “With respect to BSE in the U.S., health officials have not identified any illness in livestock or in humans caused by this disease.”
In October, the Council for Agricultural Science and Technology published a detailed analysis/assess-ment of transmissible spongiform encephalopathies in the United States and in the interpretive summary declared, “BSE has never been detected in the U.S. The overall risk for the occurrence is extremely low.”
On November 26, the Harvard Center for Risk Analysis reported their comprehensive findings of the evaluation of the potential for BSE in the United States using a probabilistic simulation model to help characterize the consequences of introducing BSE into the United States using various means and concluded that “the U.S. is highly resistant to any introduction of BSE or a similar disease. BSE is extremely unlikely to become established in the U.S.” This study used 1,000 mathematical variables to cover every potential aspect/concept of risk and could be considered a standard to emulate.
April 2004 Render