Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

DEPARTMENT OF AGRICULTURE

Animal and Plant Health Inspection Service

9 CFR Parts 92, 93, 94, 95, 96, and 98

[Docket No. APHIS-2008-0010]

RIN 0579-AC68

Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

AGENCY:

Animal and Plant Health Inspection Service, USDA.

ACTION:

Proposed rule.

SUMMARY:

We are proposing to amend the regulations that govern the importation of animals and animal products to revise the conditions for the importation of live bovines and products derived from bovines with regard to bovine spongiform encephalopathy (BSE). We are proposing to base importation conditions on the inherent risk of BSE infectivity in specified commodities, as well as on the BSE risk status of the region from which the commodities originate. We are proposing to establish a system for classifying regions as to BSE risk that is consistent with the system employed by the World Organization for Animal Health (OIE), the international standard-setting organization for guidelines related to animal health. The conditions we are proposing for the importation of specified commodities are based on internationally accepted scientific literature and, except in a few instances, are consistent with guidelines set out in the OIE's Terrestrial Animal Health Code. We are also proposing to classify certain specified countries as to BSE risk and are proposing to remove BSE restrictions on the importation of cervids and camelids and products derived from such animals. We are proposing to make these amendments after conducting a thorough review of relevant scientific literature and a comprehensive evaluation of the issues and concluding that the proposed changes to the regulations would continue to guard against the introduction of BSE into the United States, while allowing the importation of additional animals and animal products into this country. In this document we are also affirming the position we took in removing the delay of applicability of certain provisions of the rule entitled “Bovine Spongiform Encephalopathy; Minimal-Risk Regions and Importation of Commodities,” published in the

Federal Register

on January 4, 2005 (70 FR 460-553). The delay of applicability was removed in a final rule entitled “Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines,” published in the

Federal Register

on September 18, 2007 (72 FR 53314-53379).

DATES:

We will consider all comments that we receive on or before May 15, 2012.

ADDRESSES:

You may submit comments by either of the following methods:

•

Federal eRulemaking Portal:

Go to

http://www.regulations.gov/#!documentDetail;D=APHIS-2008-0010-0001.

•

Postal Mail/Commercial Delivery:

Send your comment to Docket No. APHIS-2008-0010, Regulatory Analysis and Development, PPD, APHIS, Station 3A-03.8, 4700 River Road Unit 118, Riverdale, MD 20737-1238.

Supporting documents and any comments we receive on this docket may be viewed at

http://www.regulations.gov/#!docketDetail;D=APHIS-2008-0010

or in our reading room, which is located in room 1141 of the USDA South Building, 14th Street and Independence Avenue SW., Washington, DC. Normal reading room hours are 8 a.m. to 4:30 p.m., Monday through Friday, except holidays. To be sure someone is there to help you, please call (202) 690-2817 before coming.

FOR FURTHER INFORMATION CONTACT:

For information concerning live ruminants, contact Dr. Betzaida Lopez, Import Animal Staff Veterinarian, Technical Trade Services, Animals, Organisms and Vectors, and Select Agents, National Center for Import and Export, VS, APHIS, 4700 River Road Unit 39, Riverdale, MD 20737-1231; (301) 851-3364.

For information regarding ruminant products and for other information regarding this proposed rule, contact Dr. Christopher Robinson, Assistant Director, Technical Trade Services, Animal Products, National Center for Import and Export, VS, APHIS, 4700 River Road Unit 38, Riverdale, MD 20737-1231; (301) 734-3277.

SUPPLEMENTARY INFORMATION:

I. Overview

Background

In order to guard against the introduction of animal diseases, the Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture (USDA or Department) regulates the importation of animals and animal products into the United States. The regulations in parts 92, 93, 94, 95, 96, and 98 of the U.S. Code of Federal Regulations (CFR) (referred to below as the regulations) govern the importation of certain animals, birds, poultry, meat, other animal products and byproducts, hay, and straw into the United States in order to prevent the introduction of various animal diseases, including bovine spongiform encephalopathy (BSE), a chronic degenerative disease that affects the central nervous system of cattle. In this document we are proposing to amend the import regulations related to BSE.

Nature of BSE

BSE belongs to the family of diseases known as transmissible spongiform encephalopathies (TSEs). All TSEs affect the central nervous system of infected animals. However, the distribution of infectivity in the body of the animal and mode of transmission differ according to the species and the TSE agent. In addition to BSE, TSEs include, among other diseases, scrapie in sheep and goats, chronic wasting disease in deer and elk, and Creutzfeldt-Jakob disease in humans.

The agent that causes BSE has yet to be fully characterized. The theory that is most accepted in the international scientific community is that the agent is an abnormal form of a normal protein known as cellular prion protein. The BSE agent does not evoke a traditional immune response or inflammatory reaction in host animals. BSE is confirmed by post-mortem examination of an animal's brain tissue, which may include detection of the abnormal form of the prion protein in the brain tissues. The pathogenic form of the protein is both less soluble and more resistant to degradation than the normal form. The BSE agent is resistant to heat and to normal sterilization processes.

BSE is not a contagious disease, and therefore is not spread through casual contact between animals. Scientists believe that transmission is through ingestion of feed that has been contaminated with a sufficient amount of tissues or organs containing the BSE agent from an infected animal. This route of transmission can be prevented by excluding from ruminant feed tissues or organs that could potentially carry the BSE agent.

Other characteristics of the BSE agent, as evidenced by epidemiology, transmission studies, and pathogenesis are discussed in detail in a final rule APHIS published in the

Federal Register

on September 18, 2007 (72 FR 53314-53379, Docket No. APHIS-2006-0041) and in the supporting scientific

documentation that was prepared for this proposed rule. (The supporting scientific documentation can be accessed at the APHIS Web site at

http://www.aphis.usda.gov/newsroom/hot_issues/bse/downloads/RiskAssessment06-041-1%20.pdf).

Roles of Different Agencies

APHIS, an animal health agency within USDA, promulgates its regulations regarding BSE under the authority of the Animal Health Protection Act (7 U.S.C. 8301

et seq.

), which gives the Secretary broad discretion to regulate the importation of animals and animal products if necessary to protect the health of U.S. livestock.

Because variant Creutzfeldt-Jakob Disease (vCJD) in humans has been linked to exposure to the BSE agent, APHIS collaborates with other Federal agencies with regulatory responsibility for assuring food safety and the protection of human health to implement a comprehensive coordinated U.S. response to BSE. Within USDA, protecting human health from the risks of BSE is carried out by the Food Safety and Inspection Service (FSIS), the agency charged with responsibility for administering the Federal Meat Inspection Act, which was enacted to ensure that meat and meat food products distributed in commerce are wholesome, not adulterated, and properly marked, labeled, and packaged. The USDA agencies carry out their programs in close coordination with the following Centers of the Food and Drug Administration (FDA) of the U.S. Department of Health and Human Services: The Center for Veterinary Medicine regarding animal feed and veterinary pharmaceuticals; the Center for Food Safety and Applied Nutrition regarding foods other than meat, poultry, and egg products; and other Centers regarding drugs, biologics, and devices containing bovine material. These agencies collaborate, issuing regulations under their respective authorities. Imported products must meet all relevant agency requirements. Each agency has the capability to deny imports based on their individual authorities and concerns.

Rulemaking Regarding BSE

The protective measures the Federal Government has taken have evolved over the years, as scientific understanding of the disease has increased. In 1989, APHIS prohibited the importation of live cattle and other ruminants and certain ruminant products, including most rendered protein products, into the United States from countries where BSE is known to exist, and codified this prohibition in the CFR on April 30, 1991 (56 FR 19794-19796, Docket No. 90-252). The list of regions in which BSE is known to exist is set out in the current regulations in § 94.18(a)(1).

In June 1997, FDA prohibited the use of all mammalian protein—with the exception of pure pork and pure equine protein from single species processing plants and certain other materials—in animal feeds given to cattle and other ruminants, and established measures to protect against the contamination of “allowable” feed material with materials that could contain the BSE agent. We discuss this and other FDA actions regarding BSE in this document under the heading “Evolution of U.S. Regulatory Response to BSE.”

In rulemaking made effective December 12, 1997, and published in the

Federal Register

on January 6, 1998, APHIS added to the regulations a category of regions that pose an undue risk of introducing BSE into the United States. In the rulemaking document establishing that category (63 FR 406-408, Docket No. 97-127-1), we explained that our decision to add the category was based on developments that led us to believe that, at the time, the BSE agent might have been present but as yet undetected throughout Europe. We noted that the Netherlands, Belgium, and Luxembourg had recently reported their first case of BSE in native-born cattle. Additionally, we noted that Belgium and Luxembourg had reported that cattle diagnosed with BSE had inadvertently been processed into the animal food chain. We concluded that, because of the movement of ruminants and ruminant products within Europe, the possibility existed that this potentially contaminated animal feed might have been moved to other European countries.

In our 1997 rulemaking, we applied the same import prohibitions and restrictions to regions of undue risk for BSE that were being applied to regions listed as those in which BSE is known to exist. The list of regions of undue risk for BSE is set out in the current regulations in § 94.18(a)(2). Imports from any region not listed in either of those two categories were not subject to any BSE prohibitions or restrictions.

In December 2000, APHIS expanded its prohibitions on imports of rendered ruminant protein products from BSE-restricted regions to include rendered protein products of any animal species because of concern that cattle feed supposedly free of ruminant protein may have been cross-contaminated with the BSE agent (66 FR 42595-42601, Docket No. 00-121-1). FDA also issued import alerts on animal feed ingredients for APHIS-listed countries.

On November 4, 2003, APHIS published a proposed rule in the

Federal Register

(68 FR 62386-62405, Docket No. 03-080-1) in which we proposed to establish a category of regions that present a minimal risk of introducing BSE into the United States via live ruminants and ruminant products and byproducts, and to add Canada to this category. The proposal also set forth conditions for the importation of certain live ruminants and ruminant products and byproducts from BSE minimal-risk regions.

In the November 2003 proposal, we set forth factors that would be taken into account in determining whether a country qualified as a BSE minimal-risk region. According to our proposed definition of a BSE minimal-risk region, such measures would include importation restrictions, surveillance, and a feed ban. With regard to a feed ban, we proposed that, to be recognized as a BSE minimal-risk region, a country must have in place a ban on the feeding of ruminant protein to ruminants that appears to be an effective barrier to the dissemination of the BSE infectious agent, with no evidence of significant noncompliance with the ban.

On December 25, 2003, less than 2 weeks before the close of the comment period for the proposed rule, a case of BSE in a dairy cow of Canadian origin in Washington State was verified by an international reference laboratory. Subsequently, both FSIS and FDA implemented significant additional measures in the United States to protect human health. In addition, APHIS commenced an enhanced BSE surveillance program to determine the incidence of the disease in the United States.

The measures taken by Federal agencies in January 2004 led to a change in APHIS' November 2003 proposed rule. Among the actions taken by FSIS to supplement its measures to prevent the BSE agent from entering the human food supply was to designate as specified risk materials (SRMs) certain tissues from cattle 30 months of age and older, and the tonsils and distal ileum of the small intestine of all cattle, and to prohibit their use as human food. FSIS also required all slaughtering and processing establishments to develop, implement, and maintain written procedures for the removal, segregation, and disposition of SRMs. FSIS did not restrict the age of cattle eligible for slaughter, because the removal of SRMs effectively mitigates the BSE risk to humans associated with cattle that pass

both ante-mortem and post-mortem inspections (i.e., apparently healthy cattle). (We discuss below additional BSE-related regulatory actions taken by FSIS and FDA under the heading “Evolution of U.S. Regulatory Response to BSE.”)

The risk mitigation measures that FSIS implemented regarding slaughtered cattle had ramifications for the importation of bovine-derived meat from other countries. Pursuant to the Federal Meat Inspection Act, countries that export meat to the United States must implement food safety requirements that are equivalent to those in place in the United States. To be eligible to export beef to the United States, a country must have in place a system to effectively keep SRMs out of the production chain and to prevent cross-contamination of beef with SRMs. FSIS determined the SRM requirements implemented by Canada in July 2003 to be equivalent to FSIS' requirements. Additionally, FDA's feed ban prohibits most mammalian protein, including ruminant protein, from entering the ruminant feed chain in the United States.

On March 8, 2004, APHIS published a document in the

Federal Register

(69 FR 10633-10636, Docket No. 03-080-2) explaining the effects on our proposed rule of the detection of BSE in the State of Washington in a cow imported from Canada and of the additional measures taken by FSIS, APHIS, and FDA. That document explained why the detection of an imported BSE-infected cow did not alter the conclusions we had reached in our original risk assessment. It explained further that, in fact, the resulting additional measures put in place by FSIS provided a basis for removing from the proposed provisions an age restriction on cattle from which meat would be derived for export to the United States. Accordingly, we proposed to allow the importation of beef derived from cattle of any age. To give the public additional time to comment on the proposal in light of these developments, we reopened and extended the comment period for an additional 30 days.

On January 4, 2005, APHIS published in the

Federal Register

(70 FR 460-553, Docket No. 03-080-3) a final rule that established the criteria for BSE minimal-risk regions, listed Canada as a BSE minimal-risk region, and specified importation requirements for live animals, and meat products and byproducts. The final rule allowed the importation of meat from bovines of any age, as we had proposed on March 8, 2004. The final rule was scheduled to become effective on March 7, 2005.

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On March 2, 2005, Judge Richard F. Cebull of the U.S. District Court for the District of Montana ordered that the implementation of APHIS' January 4, 2005, final rule be preliminarily enjoined. On July 14, 2005, the U.S. States Court of Appeals for the Ninth Circuit ordered that the preliminary injunction order be vacated and the case remanded to the District Court.

In January 2005, BSE was confirmed in two cows in Canada.

On March 11, 2005, APHIS published a document in the

Federal Register

(70 FR 12112-12113, Docket No. 03-080-6) that, pursuant to an announcement by the Secretary of Agriculture on February 9, 2005, delayed the applicability of the provisions of the January 2005 final rule as they applied to the importation from Canada of certain commodities, including meat, meat food products, and meat byproducts other than liver when derived from bovines 30 months of age or older when slaughtered. We discuss the delay of applicability in more detail, below.

On August 18, 2005, APHIS published in the

Federal Register

(70 FR 48494-48500, Docket No. 05-004-1) a proposed rule to amend the regulations by allowing, under certain conditions, the importation of whole cuts of boneless beef from Japan.

On November 28, 2005, APHIS published in the

Federal Register

an interim rule (70 FR 71213-71218, Docket No. 03-080-8) that amended certain provisions established by the January 2005 final rule. The interim rule broadened the list of who is authorized to break seals on conveyances and allows transloading under supervision of products transiting the United States.

On December 14, 2005, APHIS published a final rule in the

Federal Register

(70 FR 73905-73919, Docket No. 05-004-2) that made final its August 2005 proposed rule regarding certain cuts of boneless beef from Japan. The risk assessment conducted for that rulemaking examined the evidence supporting the safety of this commodity. This evidence and APHIS' conclusions were consistent with those of the World Organization for Animal Health (OIE) for trade in meat derived from cattle from regions of controlled risk for BSE. (The risk document, “Analysis of Bovine Spongiform Encephalopathy (BSE) Risk to the U.S. Cattle Population from Importation of Whole Cuts of Boneless Beef from Japan,” can be accessed at

http://www.regulations.gov/#!documentDetail;D=APHIS-2005-0073-0002).

The OIE is the international standard-setting organization for guidelines related to animal health.

On March 14, 2006, APHIS published in the

Federal Register

a technical amendment (71 FR 12994-12998, Docket No. 03-080-9) that clarified our intent with regard to certain provisions in the January 2005 final rule and corrected several inconsistencies within the rule.

On August 9, 2006, APHIS published in the

Federal Register

a proposed rule (71 FR 45439-45444, Docket No. APHIS-2006-0026) that proposed to amend the provisions established by the January 2005 final rule by removing several restrictions regarding the identification of animals and the processing of ruminant materials from BSE minimal-risk regions, and by relieving BSE-based restrictions on hide-derived gelatin from BSE minimal-risk regions. We solicited comments concerning our proposal for 60 days ending October 10, 2006. On November 9, 2006, we published a document in the

Federal Register

(71 FR 65758-65759, Docket No. APHIS-2006-0026) reopening and extended the comment period until November 24, 2006.

On January 9, 2007, APHIS published a proposed rule in the

Federal Register

(72 FR 1101-1129, Docket No. APHIS-2006-0041) that proposed to establish conditions for the importation of the following commodities from BSE minimal-risk regions: Live bovines for any use born on or after a date determined by APHIS to be the date of effective enforcement of a ruminant-to-ruminant feed ban in the region of export;

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blood and blood products derived from bovines; and casings and part of the small intestine derived from bovines.

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Requiring that live bovines exported to the United States from BSE minimal-risk regions be born after the date of effective enforcement of a ruminant-to-ruminant feed ban is consistent with the OIE standards for the exportation of live bovines from countries classified by the OIE as having either a negligible or a controlled BSE risk. We consider effective enforcement to have been achieved after completion of the initial (or practical) period of implementation of a feed ban and after sufficient time has elapsed to allow most feed products to cycle through the system. The practical implementation period, which begins when the regulations are initially put in place, can be determined by evaluating implementation guidance and policies, such as allowing grace periods for certain aspects of the industry. In addition, the time necessary for initial education of industry and training of inspectors must be considered. After the practical implementation period is defined, we then consider the time necessary subsequent to practical implementation to allow most feed products to cycle through the system, given the management practices in the country. Effective enforcement does not necessarily mean that 100 percent compliance with the feed ban requirements will be achieved.

On September 18, 2007, APHIS published in the

Federal Register

(72 FR 53314-53379, Docket No. APHIS-2006-0041) a final rule that adopted the

changes to the regulations we had proposed in January 2007. Additionally, the September 2007 final rule removed the partial delay of applicability of the January 2005 final rule with respect to meat and certain meat products and byproducts derived from cattle over 30 months of age.

On January 18, 2008, APHIS published in the

Federal Register

a final rule (73 FR 3379-3385, Docket No. APHIS-2006-0026) that made final the provisions of our August 9, 2006, proposed rule, with some changes.

On July 3, 2008, Judge Lawrence L. Piersol of the U.S. District Court for the District of South Dakota, in response to a motion filed in that Court, ordered USDA to provide the public with notice and a further opportunity to comment on the provisions of our January 2005 final rule regarding the importation of beef from bovines 30 months of age or older when slaughtered, to consider comments made by interested parties, and to revise the rule as USDA deems necessary.

On September 18, 2008, APHIS published a request for comments in the

Federal Register

(73 FR 54083-54089), in which we provided the public with such notice and further opportunity to comment. We solicited comments for 60 days ending November 17, 2008.

In this document, we discuss the issues raised by commenters in response to our September 2008 request for comments and provide our responses to those comments. Following that discussion, we describe and discuss changes we are proposing to make to the APHIS BSE regulations. However, in order to present our responses to the comments and the changes we are proposing in the context of the available scientific research and empirical data regarding the transmission of BSE, we consider it necessary to first discuss what is known regarding SRMs and the role of feed bans in reducing BSE risk.

Tissue Localization

Some bovine tissues have demonstrated infectivity, whereas others have not. Most of the information on the development and distribution of tissue infectivity in BSE-infected cattle has been derived from experimental pathogenesis studies conducted in the United Kingdom and Germany (Wells,

et al.,

1994; 1996; 1998; 1999; 2005; EFSA 2007; Hoffman 2007; Hoffman 2011). In these studies, cattle were deliberately infected with BSE through oral exposure to the brain tissue of cattle with confirmed BSE. Subsets of the experimentally infected cattle were killed at regular intervals as the disease progressed. At each interval, the tissues of the infected cattle were examined for histopathological changes consistent with BSE and for abnormal prion proteins. Also, at each interval, a mouse assay was done—i.e., tissues of the BSE-infected cattle were injected intracerebrally and intraperitoneally into different types of mice (e.g., wild mice and mice genetically altered to be highly susceptible to BSE) to identify those tissues of cattle containing infectivity.

The first United Kingdom pathogenesis studies involved 30 animals, each of which received a single dose of 100g of infected brain at 4 months of age (Wells,

et al.,

1994; 1996; 1998; 1999; 2005). This dose is probably 10-100 times greater than that associated with field exposure via feed (DEFRA, 2006). The studies demonstrate that in cattle infected with BSE, the total amount of infectivity in the animal, as well as the distribution of infectivity in the animal's body, changes over time (Wells,

et al.,

1994; 1996; 1998; 1999; 2005). The highest levels of infectivity were detected in the brain and spinal cord at the end stages of disease. Some cattle exhibited clinical signs of BSE as early as 35 months after oral exposure to the BSE agent. By 37 months after oral exposure, all five animals that were still alive demonstrated clinical evidence of BSE. Infectivity was found in cattle with clinical signs of BSE in the brain, spinal cord, DRG,

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trigeminal ganglia, and the distal ileum of the small intestine.

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DRG are clusters of nerve cells attached to the spinal cord that are contained within the bones of the vertebral column. “DRG” as used in this document has the same meaning as the term “dorsal spinal nerve root ganglia.” Trigeminal ganglia are clusters of nerve cells connected to the brain that lie close to the exterior of the skull.

BSE infectivity was demonstrated in the brain, spinal cord, and DRG as early as 32 months after oral exposure to the BSE agent in some cattle (Wells,

et al.,

1994; 1996; 1998; 1999; 2005). Infectivity was demonstrated in these tissues 3 months before animals began to develop clinical signs of the disease. Infectivity was demonstrated in the distal ileum of cattle 6 to 18 months after oral exposure to the BSE agent and again at 38 months and 40 months after oral exposure. A similar study (Espinosa,

et al.,

2007) examined the infectivity of tissues from these same animals by intracerebral inoculation of highly sensitive transgenic mice overexpressing bovine PrP (prion protein). This study's findings were similar to those of Wells,

et al.,

described above. In addition, infectivity in the sciatic nerve was found at low levels only after 30 months from exposure. No detectable infectivity was found in the spleen, skeletal muscle, blood, or urine of asymptomatic cattle.

As explained by the United Kingdom's Department for Environment, Food and Rural Affairs (DEFRA) and by the European Commission's Scientific Steering Committee, a second phase of the pathogenesis studies, which used a cattle bioassay as an endpoint, was conducted to ensure that low levels of infectivity that may not have been detected in the first phase using the mouse bioassay were not missed (DEFRA, 2006; EC SSC 2002). This second phase of the study was completed in March 2007 (Gerald Wells, personal communication, 2008).

In the cattle bioassay, tissues from the same cattle orally exposed to BSE in the earlier pathogenesis studies were injected directly into the brain of BSE-free cattle (DEFRA, 2006). This method is considered to be several hundred-fold more sensitive in detecting BSE infectivity than the mouse bioassay (DEFRA, 2006). Preliminary results from the cattle bioassay study demonstrate that, in addition to the materials that were found to contain infectivity when the mouse bioassay was used, the tonsils of calves 10 months after oral exposure to the BSE agent also contain infectivity. However, because only one of five animals injected with tonsil material from infected animals developed clinical BSE at 45 months post-inoculation, the level of infectivity in the tonsils appears to be very low.

BSE infectivity has not been demonstrated in the muscle tissue of BSE-infected cattle examined in these studies through either the mouse bioassay or the cattle assays (Wells 1996; 2005; personal communication 2008). All assays of the skeletal muscle pools were completed in March 2007 (Wells, personal communication 2008).

A larger pathogenesis study conducted in Germany involved calves that were orally challenged with macerated brainstems from BSE-positive cattle (EFSA 2007; Hoffman 2007). Every 4 months, randomly selected animals are euthanized and necropsied, and more than 150 tissue and bodily fluid samples are collected from each animal and analyzed by immunohistochemistry, pure-tone average Western blot, and transgenic mouse bioassay (TgbovXV). The initial results from the German BSE pathogenesis study demonstrate that BSE prions can reach the brain as soon as 24 months after a massive oral challenge (Hoffman 2007).

In addition to these studies on experimentally infected cattle,

distribution of tissue infectivity has also been studied in cattle exposed to BSE under field conditions. In these animals, at the end stages of the incubation period with demonstrated clinical signs, BSE infectivity has been confirmed by mouse bioassay only in the brain, spinal cord, and retina of the eye (EC SSC 2001).

In a 2005 study, mice genetically engineered to be highly susceptible to BSE and to overexpress the bovine prion protein were inoculated with tissues from an end-stage clinically affected BSE-infected cow (Buschmann and Groschup, 2005). The sensitivity of these mice to infection is significantly greater than other mice panels used in bio-assays, and the sensitivity is even greater than that of cattle by approximately tenfold. Using these highly sensitive mice, this study demonstrated low levels of infectivity in the facial and sciatic nerves of the peripheral nervous system of the cow. While this study, and the 2007 study by Espinosa,

et al.,

produced interesting findings that can help further characterize the pathogenesis of BSE, they cannot be extrapolated into the context of the risk presented by natural (i.e., field) exposure pathways. The findings may be influenced by the overexpression of prion proteins in these genetically engineered mice. Any apparent levels of infectivity are low in these extremely sensitive mice and would be even lower in other species such as cattle. Moreover, the route of administration to the mice was both intraperitoneal and intracerebral, both of which are very efficient routes of infection as compared to oral consumption.

Tissues that have demonstrated infectivity, and thus are likely to contain the infectious BSE agent in infected cattle, are brain, tonsil, spinal cord, eyes, trigeminal ganglia, DRG, and distal ileum. Approximately 90 percent of the infectivity is associated with the brain, spinal column, DRG, and trigeminal ganglia. The remaining 10 percent is associated with the infectivity in the distal ileum. In BSE, as with other TSEs, the total amount of infectivity in an animal increases throughout the incubation period, reaching the highest load at the end of that period, very close to the death of the animal. Infectivity is considered to increase exponentially, reaching 4.5 logs less than a clinical case at 50 percent of the incubation period and 3 logs less than a clinical case by 70 percent of the incubation period (Comer and Huntly, 2003).

All of this research has contributed to the definition of which tissues should be considered SRMs. Both the types of tissues and the understanding of the progression of the infectivity throughout the incubation period contribute to the definition of SRMs. Affiliated tissues or structures such as skull or vertebral column are also considered risk materials because of the difficulty in separating out small tissues such as DRG from the vertebral column. The risks associated with tissue localization can be mitigated by excluding SRMs from the food or feed chain or by excluding them completely from importation. FSIS and FDA regulations regarding SRMs, which we discuss below under the heading “Evolution of U.S. Regulatory Response to BSE,” are based on this scientific knowledge and an understanding of the mitigative effects of exclusion of SRMs (FSIS, 2004; 2004a; 2004b; 2005; 2007; FDA, 2004; 2005; 2007; 2008).

The measures taken by FSIS included declaring SRMs to be inedible and requiring their removal from cattle at slaughter. As noted above, even if a BSE-infected cow 30 months or older that was presented for slaughter were not exhibiting clinical signs of the disease and passed ante-mortem and post-mortem inspections, the removal of SRMs from the cow would effectively mitigate the BSE risk to humans.

Within USDA, APHIS and FSIS review and consider carefully, on an ongoing basis, all BSE research regarding the definition of SRMs, as do other countries that participate in the OIE. U.S. regulations regarding SRM removal are consistent with international guidelines.

Feed Bans

As noted, scientists believe that the route of field transmission in animals is through ingestion of feed that has been contaminated with tissues or organs containing the BSE agent from an infected animal. This route of transmission can be prevented by excluding potentially contaminated materials from ruminant feed.

Experience internationally in countries with BSE has demonstrated that feed bans are effective control measures and that the incidence of BSE worldwide continues to decline because of these measures (OIE, 2010). In the United States, prohibitions on the use of ruminant protein in ruminant feed are imposed by FDA to mitigate the risk of BSE transmission.

Because of the demonstrated efficacy of an effectively enforced feed ban in reducing the possibility of exposure of cattle to the BSE agent, the OIE provides guidelines for trade in live cattle from regions that have reported BSE if such regions have an effective feed ban in place, provided the cattle were born after the date when the feed ban was effectively enforced.

By eliminating transmission, an effective feed ban reduces the possibility of the existence of infected animals in a given cattle population, which in turn reduces further the chances of healthy animals being exposed to the BSE agent via subsequent recycling of infectivity.

September 2008 Request for Comments

As we discussed earlier in this document, the final rule that APHIS published in January 2005 to establish criteria for BSE minimal-risk regions, list Canada as a BSE minimal-risk region, and specify importation requirements for live animals, and meat products and byproducts was the outcome of a rulemaking process that APHIS initiated in 2003 to update its BSE regulations to reflect the latest scientific data and knowledge of the disease.

As discussed above, in our November 2003 proposal, we set forth factors that would be taken into account in determining whether a country qualified as a BSE minimal-risk region. According to our proposed definition of a BSE minimal-risk region, such measures would include importation restrictions, surveillance, and a feed ban. With regard to a feed ban, we proposed that, to be recognized as a BSE minimal-risk region, a country must have in place a ban on the feeding of ruminant protein to ruminants that appears to be an effective barrier to the dissemination of the BSE infectious agent, with no evidence of significant noncompliance with the ban.

We explained the role a feed ban plays in reducing BSE risk, stating that the primary source of BSE infection is feed contaminated with the infectious agent, that scientific evidence shows that feed contamination results from the incorporation of ingredients that contain abnormal ruminant protein derived from specific tissues from infected animals, and that bans prohibiting incorporation of ruminant protein into ruminant feed are imposed to mitigate risk (Wilesmith,

et al.,

1988; 1991; 1992).

In subsequent rulemaking documents, we elaborated further on the role and effect of a feed ban. In our January 2007 proposed rule, which we described earlier in this document, we discussed data associated with a ruminant-to-ruminant feed ban in the United Kingdom and indicated that experience in the United Kingdom demonstrates that implementation of a ruminant-to-ruminant feed ban causes BSE

prevalence to decrease. We noted that as a result of reducing the recycling of infectivity in the United Kingdom, the annual incidence of BSE fell by 99.4 percent, from 36,680 animals in 1992 to 203 in 2005 (DEFRA 2006a) and concluded that there is every reason to expect downward pressure on the prevalence of BSE in any country that implements a feed ban.

The conditions for the importation of ruminant products and byproducts from BSE minimal-risk regions that we proposed in November 2003 were proposed as changes to parts 94 and 95 of the regulations. The commodities addressed by the proposed changes to part 94 included meat and other edible products derived from ruminants. Part 95 addressed the importation of byproducts derived from ruminants.

Changes Regarding the Importation of Meat From Bovines Proposed in November 2003

As set forth in our November 2003 proposed rule, the provisions in part 94 for the importation of meat derived from bovines from BSE minimal-risk regions required that the following conditions be met:

• The meat is derived from bovines that were less than 30 months of age when slaughtered and that are not known to have been fed ruminant protein, other than milk protein, during their lifetime;

• The bovines from which the meat is derived were slaughtered at a facility that either slaughters only bovines less than 30 months of age or complies with a segregation process approved by the national veterinary authority of the region of origin and the APHIS Administrator as adequate to prevent contamination or commingling of the meat with products not eligible for importation into the United States;

• The intestines of the bovines were removed at slaughter; and

• The product qualifies as meat under the definition of

meat

in the FSIS regulations at 9 CFR 301.2.

As noted, one of the conditions for the importation of bovine-derived meat from BSE minimal-risk regions was that the bovines from which the meat is derived be less than 30 months of age when slaughtered. The relevance of the age of the animal to the risk of BSE, which we explained earlier in this document under the heading “Tissue Localization,” pertains to which tissues in a BSE-infected bovine have been demonstrated to contain BSE infectivity and the age at which a BSE-infected animal has been found to show infectivity in those tissues. In essence, as we stated in our November 2003 proposed rule, the proposed restriction on the age of the animals from which the commodity was derived was a measure to guard against the importation of, or contamination of meat through contact with, SRMs.

As noted above, after a BSE-infected cow of Canadian origin was discovered in Washington State in December 2003, both FSIS and FDA implemented significant additional measures in the United States to protect human health. Among the measures taken by FSIS and FDA was to declare SRMs to be inedible and require their removal from cattle at slaughter. FSIS designated as SRMs the brain, skull, eyes, trigeminal ganglia, spinal cord, vertebral column (excluding the vertebrae of the tail, the transverse process of the thoracic and lumbar vertebrae, and the wings of the sacrum), and DRG of cattle 30 months of age or older, and the tonsils and distal ileum of the small intestine of all cattle. To ensure effective removal of the distal ileum, FSIS also required all slaughtering and processing establishments to develop, implement, and maintain written procedures for the removal, segregation, and disposition of SRMs. Establishments were specifically required to implement procedures to address the potential contamination of edible materials with SRMs before, during, and after entry into the establishment. As noted above, FSIS did not restrict the age of cattle eligible for slaughter. Even if a BSE-infected cow 30 months or older that was presented for slaughter were not exhibiting clinical signs of the disease and passed ante-mortem and post-mortem inspections, the removal of SRMs from the cow would effectively mitigate the BSE risk to humans.

As discussed above, pursuant to the Federal Meat Inspection Act, implementation in the United States of those mitigation measures by FSIS meant that any country seeking to export beef to the United States would have to have equivalent mitigation measures in place. FSIS determined the SRM requirements implemented by Canada in July 2003 to be equivalent to FSIS' requirements.

As noted above, in March 2004, APHIS published a proposed rule and reopening of comment period in the

Federal Register

in which we explained why the detection of an imported BSE-infected cow did not alter the conclusions we had reached in the assessment of risk on which our November 2003 proposed rule was based. We explained further that, in fact, the resulting additional measures put in place by FSIS (i.e., declaring SRMs to be inedible and requiring their removal from cattle at slaughter) provided a basis for our removing from the provisions we had proposed in November 2003 the age restriction on cattle from which meat could be derived for export to the United States. In the March 2004 proposed rule and reopening of comment period, we stated that we did not believe it was necessary to require that beef imported from BSE minimal-risk regions be derived only from cattle less than 30 months of age, provided measures equivalent to those established by FSIS in the United States to ensure that SRMs are removed when the animals are slaughtered are in place in the exporting country and that such other measures as are necessary are in place.

As noted above, in January 2005 we published in the

Federal Register

a final rule that established the criteria for BSE minimal-risk regions, listed Canada as a BSE minimal-risk region, and specified conditions for the importation from BSE minimal-risk regions for live animals and meat, meat byproducts, and meat food products. For the reasons we discussed in our March 8, 2004,

Federal Register

document, the final rule did not limit the importation of bovine-derived meat from Canada to that derived from cattle younger than 30 months of age. In the final rule, we set forth in part 94 the following conditions for the importation from BSE minimal-risk regions of meat, meat byproducts, and meat food products derived from bovines:

• The bovines from which the meat, meat byproduct, or meat food product is derived have been subject to a ruminant feed ban equivalent to the requirements established by the U.S. Food and Drug Administration at 21 CFR 589.2000;

• The meat, meat byproduct, or meat food product is derived from bovines for which an air-injected stunning process was not used at slaughter; and

• The SRMs and small intestine of the bovines were removed at slaughter.

As noted above, in March 2005, APHIS published a document in the

Federal Register

that, pursuant to an announcement by the Secretary of Agriculture on February 9, 2005, delayed the applicability of the provisions of the January 2005 final rule as they applied to the importation from Canada of the following commodities when derived from bovines 30 months of age or older when slaughtered: (1) Meat, meat food products, and meat byproducts other than liver; (2) whole or half carcasses; (3) offal; (4) tallow composed of less than 0.15 percent insoluble impurities that is not otherwise eligible for importation under 9 CFR 95.4(a)(1)(i); and (5) gelatin

derived from bones of bovines that is not otherwise eligible for importation under 9 CFR 94.18(c).

In his February 9, 2005, announcement, the Secretary stated that, because ongoing investigations into the January 2005 finds of BSE in Canada in animals over 30 months of age were not complete, he felt it prudent to delay the effective date for allowing imports of meat from bovines 30 months of age and over. He also indicated that the delay of applicability would address concerns that the January 2005 final rule allowed the importation of meat from bovines 30 months of age or older while continuing to prohibit the importation of live cattle 30 months of age or older for processing in the United States. The Secretary stated that the Department would consider and develop a plan—based on the latest scientific information and with the protection of public and animal health as the highest priority—to allow imports of live bovines 30 months of age or older.

As discussed earlier in this document, in January 2007 we published a proposed rule in the

Federal Register

to, among other things, establish conditions for the importation from BSE minimal-risk regions of live bovines for any use born on or after a date determined by APHIS to be the date of effective enforcement of a ruminant-to-ruminant feed ban in the region of export.

As noted above, in September 2007, we published a final rule in the

Federal Register

that adopted the changes to the regulations we had proposed in January 2007. Additionally, the September 2007 final rule removed the partial delay of applicability of the January 2005 final rule with respect to meat and certain meat products and byproducts derived from cattle over 30 months of age that we addressed in our March 2005 notice. In our September 2007 final rule, we stated that, subsequent to implementation of the partial delay of applicability, “we [had] obtained additional information regarding all aspects of the issues that prompted the delay of applicability and [had] conducted additional analyses” as indicated by the Secretary in February 2005 to allow imports of live bovines 30 months of age or older (72 FR 53316).

As we concluded in our September 2007 final rule, the risk assessment for that final rule demonstrates the negligible BSE risk from the importation of additional classes of live bovines, including those 30 months of age or older.

II. Issues Raised in Response to Request for Comments

The September 2007 final rule, which included the removal of the partial delay of applicability of the provisions of the January 2005 rule relating to meat derived from cattle 30 months of age or older, became effective on November 19, 2007.

As noted above, on September 18, 2008, we published in the

Federal Register

a document that provided the public with notice and further opportunity to comment on the provisions of our January 2005 final rule regarding the importation from BSE minimal-risk regions of beef from bovines 30 months of age or older when slaughtered, for which the delay of applicability was removed in our September 2007 final rule. We solicited comments for 60 days ending November 17, 2008.

We received 12 comments by that date, including one submission that included a compilation of comments from a large number of individuals. The comments were from individual private citizens; associations of producers of livestock and other agricultural commodities, both in the United States and Canada; associations of meat processors; a consumer organization; and the Government of Canada. We carefully considered all comments received and we discuss in the following section the issues raised by the commenters and our response to those issues.

Comments in Support of the Removal of the Delay of Applicability

Five of the comments expressed support for the removal of the delay of applicability of provisions of our January 2005 final rule.

The remainder of the commenters opposed the removal of delay of applicability. Of those commenters, several provided no information to support their opposition. Others expressed general concern that allowing the importation of bovines and commodities derived from bovines from BSE minimal-risk regions would create an unacceptable disease risk. We discuss in the following section specific issues raised by commenters who opposed the removal of delay of applicability.

Meat Derived From Bovines Less Than 30 Months of Age

As noted above, one of the import conditions in the November 2003 proposed rule was that meat imported from bovines slaughtered in BSE minimal-risk regions be derived from bovines less than 30 months of age when slaughtered. Also as noted, in March 2004 we published a proposed rule and a reopening of the comment period for the November 2003 proposed rule. We explained in that document that we believed BSE risk mitigation measures implemented by FSIS subsequent to our November 2003 proposed rule provided a basis for removing from the proposed provisions the requirement that beef imported from BSE minimal-risk regions be derived only from cattle less than 30 months of age, with the provision that equivalent measures are in place to ensure that SRMs are removed when the animals are slaughtered and that such other measures as are necessary are in place.

Issue:

In our September 2008 request for comments, we included a chronology of the relevant rulemaking documents that had preceded the request for comments and referenced our March 2004 proposed rule and reopening of the comment period for the November 2003 proposed rule. One commenter stated that, in our September 2008 document, we mischaracterized our March 2004 proposed rule and reopening of the comment period as proposing to allow the importation from BSE minimal-risk regions of beef derived from cattle of any age. The commenter stated that the March 2004 proposed rule and reopening of the comment period contained no reference to the importation of beef from cattle of any age and instead continued to propose a restriction on the age of cattle by retaining the requirement contained in the November 2003 proposed rule that the beef be derived from animals that are not known to have been fed ruminant protein, other than milk protein, during their lifetime.

Response:

When we stated in our September 2008 request for comments that our March 2004 proposed rule and reopening of the comment period proposed to allow the importation of beef derived from cattle of any age, our intent was to explain that, under the provisions of the March 2004 proposed rule and reopening of the comment period, the fact that bovines from which meat and meat products intended for importation into the United States from a BSE minimal-risk region were 30 months of age or older when slaughtered would not in itself preclude the commodities from being imported. We were not referring to any effect the feed ban requirement might have on the import eligibility of the commodities. The terminology regarding “cattle of any age” that we used in our September 2008 request for comments was

consistent with that which we used in the risk analysis for our January 2005 final rule (APHIS, 2004).

Issue:

One commenter noted that the risk assessment APHIS conducted for its January 2005 final rule identified as a requirement for the importation of bovine-derived meat and meat products from a BSE minimal-risk country that veterinary officials in the exporting country certify that the animals from which the meat and meat products were derived were subject to a feed ban considered equivalent to that in place in the United States. The commenter also noted that APHIS' November 2003 proposed rule included a requirement that bovine-derived meat imported from a BSE minimal-risk region be derived from bovines that were not known to have been fed ruminant protein, other than milk protein, during their lifetime.

The commenter noted, further, that, in APHIS' September 2008 request for comments, we stated that, with respect to the importation of meat, the 30-month age restriction contained in our November 2003 proposed rule was a measure to guard against the importation of, or contamination of meat through contact with, tissues other than meat that have the potential of containing high levels of BSE infectivity. According to the commenter, that wording mischaracterized APHIS' rationale in the November 2003 proposed rule regarding the 30-month age restriction on bovines from which meat and meat products were derived. The commenter stated that APHIS' true intention regarding the 30-month age restriction was to prevent the importation of products derived from Canadian cattle that had been exposed to BSE infectivity.

The commenter cited text from the risk assessment conducted for APHIS' 2005 final rule that stated that the risk of introducing BSE infectivity can be reduced by requiring that animals presented for export and animals from which meat or meat products intended for export were derived were subject to a ruminant feed ban. Additionally, the commenter cited text from (1) APHIS' November 2003 proposed rule that stated that animals, and the products derived from those animals, will present a lower risk if the animals were born after the implementation of an effective feed ban and (2) from the risk assessment APHIS conducted for its January 2005 final rule that stated that, in addition, Canadian cattle less than 30 months of age would have been born and raised during a time when the Canadian feed ban had been in place for more than 5 years, and, based on evidence of a high level of compliance with the feed ban, are unlikely to have been exposed to the BSE agent.

The commenter discussed APHIS' provisions regarding two specific products derived from bovines—tongues and liver—to support the commenter's contention that APHIS' true intent regarding the 30-month age restriction on bovines from which meat and meat products are derived was to prevent the importation of products derived from Canadian cattle that had been exposed to BSE infectivity, rather than to guard against the importation of, or contamination of meat through contact with, tissues other than meat that have the potential of containing high levels of BSE infectivity.

With regard to tongues, the commenter stated that APHIS' November 2003 proposed rule would have allowed the importation of bovine tongues, even tongues derived from cattle 30 months of age or older, despite the fact that APHIS acknowledged that tongues are connected to and bear the risk of contamination by tonsils, which the commenter stated have the potential of containing high levels of BSE infectivity. The commenter stated that, to mitigate this risk, APHIS proposed to require that tongues be derived from cattle from which the tonsils were removed at slaughter and that were born after the implementation of an effective feed ban and were not known to have been fed ruminant protein, other than milk protein, during their lifetime.

The commenter pointed to a similar situation regarding bovine-derived liver from BSE minimal-risk regions. The commenter stated that APHIS' November 2003 proposed rule would have allowed the importation of liver that was not subject to the 30-month age restriction, even though, according to APHIS, it was susceptible to contamination by brain emboli, tissues that have the potential of containing high levels of BSE infectivity. The commenter noted that, in APHIS' November 2003 proposed rule, the only mitigation of the potential for the contamination of liver by the BSE agent was the requirement that the liver not be derived from cattle for which an air-injected stunning process was used at slaughter. The commenter noted that in APHIS' January 2005 final rule, however, the importation of liver from BSE minimal-risk regions was governed by the same conditions as those set forth for other types of meat from bovines, including the requirement that liver be derived from bovines that were subject to a ruminant feed ban.

Response:

We consider the commenter's assertion to be inconsistent with APHIS' stated intent in its rulemaking documents and supporting risk analyses, with the regulatory provisions of previous rulemaking documents, and with internationally accepted scientific literature.

In presenting the issues noted above, the commenter seems to be incorrectly concluding that two separate risk mitigation measures we included in our November 2003 proposed rule—(1) a prohibition on the importation from BSE minimal-risk regions of bovine-derived meat and meat products from animals that were 30 months of age or older when slaughtered, and (2) a requirement that the animals from which the commodities were derived were subject to a ruminant feed ban—were intended to mitigate BSE risk in the same way, i.e., by preventing the importation of products derived from Canadian cattle that had been exposed to BSE infectivity.

The commenter's characterization of APHIS' rationale for the 30-month age restriction is inconsistent with the explanation we provided in our November 2003 proposed rule. In the November 2003 proposed rule, we explained in detail the likelihood that specific tissues in a BSE-infected bovine of a certain age will contain the disease agent and how that likelihood influences the risk of BSE transmission from an infected animal. We stated in the proposed rule that “levels of infectious agent in certain tissues vary with the age of an animal, so the age of the animal influences risk” (68 FR 62390), then discussed in detail the research findings supporting that statement. We concluded our discussion of the influence of the age of the animal on BSE risk by stating that “because BSE infectivity has not been found in most bovine tissues until at least 32 months post-exposure, we believe that by requiring that bovines imported into the United States from BSE minimal-risk regions be less than 30 months of age, the risk of the BSE agent being present at infectious levels in most tissues in the animal is minimized.” (62 FR 62391)

As we discuss earlier in this document, in our March 2004 proposed rule and reopening of the comment period, we explained that, in light of the SRM removal requirements implemented in the United States by FSIS following the diagnosis of BSE in Washington State in December 2003 in a cow imported from Canada, we did not believe it would be necessary to require that beef imported from BSE minimal-risk regions be derived only from cattle less than 30 months of age, provided equivalent measures are in place to ensure that SRMs are removed

when the animals are slaughtered, and that such other measures as are necessary are in place. In our September 2007 final rule, we emphasized that the removal and disposal of SRMs is the key factor in the food safety of products from bovines used for human consumption.

The “other measures” regarding the importation of bovine-derived meat, meat byproducts, and meat food products and meat products from BSE minimal-risk regions set forth in our January 2005 final rule were that (1) the commodity be derived from bovines that have been subject to a ruminant feed ban equivalent to the requirements established by FDA in the United States and (2) the commodity be derived from bovines for which an air-injected stunning process was not used at slaughter.

As the commenter noted, effective enforcement of a ruminant-to-ruminant feed ban reduces the risk that an animal will be exposed to the BSE agent. However, the removal of SRMs from bovines is an effective means of mitigating the risk of BSE transmission to humans from meat, meat products, and meat byproducts derived even from an exposed animal. In comparison, the BSE regulations for live bovines imported from a BSE minimal-risk region require that the animals were born after the date of effective enforcement of a ruminant-to-ruminant feed ban to reduce the likelihood that a BSE-infected live animal is imported into the United States.

Requiring that SRMs be removed from bovines from which meat and meat products are derived, as is required in both the United States and Canada, ensures that tissues containing BSE infectivity are removed even from a BSE-infected animal that might be presented for slaughter showing no visible signs of BSE. We note that the OIE Code for trade in fresh meat and meat products from cattle from countries of controlled BSE risk (both Canada and the United States are classified as countries of controlled BSE risk by the OIE) recognizes the negligible risk presented by such products as long as SRMs are removed. Therefore, the Code does not recommend that the date of birth of the animal from which the commodity was derived be a condition for such trade, or that the commodity be accompanied by certification that the animal was subject to a feed ban.

APHIS' confidence in the effectiveness of SRM removal in reducing BSE risk was demonstrated in a final rule that APHIS published in December 2005 to allow the importation, under certain conditions, of boneless beef from Japan. Although that rulemaking differs from the rulemaking APHIS conducted regarding BSE minimal-risk regions in the sense that the only commodity addressed in the Japan rulemaking was boneless beef—whereas a more extensive list of commodities was made eligible for importation into the United States from BSE minimal-risk regions—it is significant to note that the conditions in § 94.27 of the regulations for the importation of boneless beef from Japan do not include the requirement that the bovines from which the beef was derived were subject to a feed ban. The requirements for the importation of boneless beef from Japan are that it be prepared in an establishment eligible to have its products imported into the United States under the Federal Meat Inspection Act and the FSIS regulations in 9 CFR 327.2, that it meet all other applicable requirements of the Federal Meat Inspection Act and regulations thereunder (9 CFR chapter III), including the requirements for the removal of SRMs and the prohibition on the use of air-injection stunning devices prior to slaughter on cattle from which the beef is derived, and that it be derived from cattle that were not subjected to a pithing process at slaughter.

Although a ruminant-to-ruminant feed ban reduces the possibility of exposure of bovines to the BSE agent and is an important measure in mitigating the risk that BSE will be transmitted in a region, it serves a different role in BSE mitigation than does SRM removal.

Issue:

One commenter stated that APHIS, in its September 2008 request for comments, explained that the conclusion reached in the risk assessment for the September 2007 final rule regarding the negligible BSE risk from the importation of cattle from Canada, even those 30 months of age older, gave further support to the conclusion of the risk analysis conducted for APHIS' 2005 final rule that the importation of meat and meat products derived from bovines from BSE minimal-risk regions posed a low BSE risk, provided certain conditions were met.

The commenter stated that both the risk assessment for APHIS' 2007 final rule regarding the importation of live older bovines and the risk assessment for APHIS' 2005 final rule were predicated on a bovine's being subject to a feed ban during its entire lifetime and that neither the January 2005 final rule nor the risk analysis that accompanied that rule addressed the risk of BSE contamination in meat or meat products derived from cattle that were born prior to the date of effective enforcement of Canada's feed ban. Therefore, stated the commenter, APHIS had no basis to lift its restriction on the importation of beef from Canadian cattle that were over 30 months of age when slaughtered.

The commenter stated further that APHIS, in its September 2007 final rule, deleted from the regulations without explanation the requirement that bovine-derived meat and meat products imported from a BSE minimal-risk region be derived from an animal that had been subject to a feed ban.

Response:

The commenter is incorrect in stating that the September 2007 final rule removed the requirement that bovine-derived meat and meat products, and certain byproducts, imported from a BSE minimal-risk region be derived from animals that had been subject to a feed ban.

With regard to the commenter's discussion of the wording we used in our September 2008 request for comments in referring to our risk assessments, although we acknowledge that the wording we used in that document could be interpreted in several ways, our intent was to compare the likelihood of BSE introduction into the United States through the importation of live bovines from Canada with the likelihood of BSE introduction through the importation of bovine-derived meat and meat products from Canada. In making such a comparison, we referred to the risk assessments for our January 2005 and September 2007 final rules, in which we explained in detail the role of SRMs in BSE transmission and the effectiveness of reducing the likelihood of BSE transmission through the removal of SRMs at slaughter. Our point was that, if, as we concluded in our September 2007 final rule, the risk of BSE exposure in the United States from the importation of live bovines—with SRMs intact—from Canada is negligible, then the importation of bovine-derived meat and meat products from Canada would present even less of a risk, because the SRMs from the bovines from which the meat and meat products were derived would have been left behind in Canada.

Effectiveness of Canadian Inspection System

As discussed above, one of the required risk mitigation measures for bovine-derived meat and meat products imported from Canada is that the SRMs of the bovines from which the commodities are derived were removed at slaughter.

Issue:

Several commenters expressed concern about the ability of Canadian food inspectors to ensure that meat products are free from SRMs. One commenter stated that, in a 2007 audit of Canadian food establishments eligible to export to the United States, FSIS reported the following: “Inspection system controls at all levels were not fully developed and implemented. There were many instances of deficiencies both in the documentation reviews and in the operations audits that should have been addressed prior to the FSIS audit. Some inspection personnel were not well-trained in the performance of their inspection tasks.” (The commenter cited “Food Safety and Inspection Service, United States Department of Agriculture, “Final Report of an Audit Carried Out in Canada Covering Canada's Meat, Poultry, and Egg Products Inspection System, May 1 through June 6, 2007”,

http://www.fsis.usda.gov/OPPDE/FAR/Canada/Canada2007.pdf.”

)

Response:

In addressing this issue, FSIS has stated that, with respect to the FSIS audit of Canada in 2007, FSIS specifically assessed controls for SRM removal in Canada and identified no related deficiencies. With regard to the other deficiencies identified in the 2007 audit, FSIS stated that none caused FSIS to question whether the Canadian inspection system was adequate with regard to SRM control. FSIS has included a review of controls for SRM removal in its audits since 2005. In each review—including audits conducted in February 2005, April-May 2006, May-June 2007, and May-June 2008—no deficiencies were noted in relation to SRM removal and other BSE-related requirements.

Issue:

One commenter stated that the Canadian Food Inspection Agency (CFIA) is considering weakening government food inspection and turning the inspection process over to industry and that further deregulation of meat inspection in Canada would endanger U.S. public health.

Response:

In addressing this issue, FSIS has informed APHIS that FSIS has been in contact with CFIA, including follow-up discussions about possible changes to the inspection system in Canada. FSIS is not aware of any substantive planned changes at this time. Any changes affecting meat, poultry, or processed egg product destined for the United States would require discussion related to equivalency to the U.S. inspection system.

Issue:

One commenter stated that, although APHIS' September 2008 request for comments indicated that FSIS has determined that Canada has implemented food safety requirements that are equivalent to those in the United States, including Canada's July 2003 requirements regarding SRMs, there is a disparity between what FSIS is supposed to require of foreign plants that ship products to the United States and what is actually practiced.

Response:

In 2005, FSIS conducted an enforcement audit to evaluate Canada's implementation of SRM controls for products destined for the United States. FSIS concluded that SRM controls had been effectively implemented, in accordance with FSIS regulatory requirements, in Canadian establishments certified to export beef to the United States. The audit led to no delistments of eligible establishments, nor to any notices of intent to delist eligible establishments.

4

4

Delistment of an establishment removes it from the list of establishments authorized to export meat and meat products to the United States. A notice of intent to delist is issued to an establishment that conducts marginally acceptable practices, and puts it on notice that it will be delisted unless specified improvements are made.

Issue:

One commenter cited a December 2005 report by the USDA's Office of Inspector General (OIG) that stated, in part:

In July 2003, FSIS found that Canadian inspection officials were not enforcing pathogen reduction and HACCP system regulations. These same types of concerns were identified again in June 2005, almost 2 years later. However, as of September 2005, FSIS has not made a determination whether the identified concerns are serious enough to limit the import of Canadian products. As a result, FSIS has allowed the importation of almost 700 million pounds of meat and poultry from plants that did not receive daily inspection, a requirement for all U.S. meat and poultry plants. Additionally, FSIS allowed the import of over 261 million pounds of ready-to-eat meat and poultry that had not been subjected to finished product testing for

Listeria monocytogenes,

as is required of U.S. plants. (The commenter cited “Audit Report Food Safety and Inspection Service Assessment of the Equivalence of the Canadian Inspection System, U.S. Department of Agriculture, Office of Inspector General, Northeast Region, Report No. 24601-05-Hy, December 2005, at 4.”)

The commenter stated that, according to the OIG, FSIS does not have protocols or guidelines for evaluating deficiencies in a country's inspection system that could jeopardize a country's overall equivalence determination and that FSIS did not institute compensating controls to ensure that public health was not compromised while deficiencies were present.

Response:

As noted in the OIG report, FSIS addressed audit deficiencies with CFIA officials during and immediately following the 2003 and 2005 audits. For those deficiencies that had potential impact on public health, FSIS auditors required the establishments to take immediate corrective actions. In some instances, FSIS also required enforcement action to be taken by Canadian authorities. These enforcement actions included immediate delistment of the establishment or the issuance of a warning letter requiring specific corrective actions within 30 days. FSIS' analysis of the audit reviews have identified and resolved all potential public health concerns.

Issue:

One commenter stated that, in a follow-up report issued by the OIG in August 2008, the OIG reported that FSIS could not demonstrate that the number of intensified inspections for physical and laboratory failures provided the appropriate level of protection to ensure the safety and wholesomeness of imported products.

Response:

In response to Recommendation #8 of OIG audit 24601-08-Hy, FSIS agreed with OIG's findings and stated that FSIS would determine the appropriate number of intensified inspections needed following physical and laboratory failures to ensure the safety and wholesomeness of imported products.

5

After further analysis of available data, FSIS determined that the current number of intensified inspections for laboratory and physical failures is sufficient and appropriately established. Thus, according to FSIS, further revisions to the FSIS procedures for intensified inspections are unnecessary.

5

Intensified inspections are triggered after a product fails to pass reinspections for physical and laboratory testing. If the level of inspection is increased, FSIS management officials have decided to perform reinspection activities above the normal level of inspection for a lot, based on problems associated with the specific product, foreign establishment, or country.

Issue:

One commenter stated that the OIG found that FSIS could not demonstrate that it performed an adequate sampling of foreign establishments to validate that the country's inspection system is equivalent to that in the United States. The commenter stated, further, that the OIG found that FSIS did not visit the minimum number of establishments necessary to validate that inspection systems were equivalent to that in the United States in three of the four countries it reviewed and questioned whether FSIS had sufficient data to conclude that these countries' inspection systems were equivalent to the U.S. system.

Response:

In response to Recommendation #2 of OIG audit 24601-08-Hy, FSIS has developed and implemented a process to document the reasons for the number of establishments selected for an on-site country audit as part of the agenda for the pre-audit conference between FSIS and the foreign country. In addition, FSIS has implemented a statistically based sampling plan using a country's recent history of overall compliance with FSIS requirements, as well as information provided by the country on a continuous basis, in determining that the foreign country's inspection system is performing adequately.

Efficacy of SRM Removal in Mitigating the Risk of BSE

Issue:

One commenter stated that the risk modeling the commenter said APHIS relies on to support its claim that SRM removal alone is sufficient to mitigate the potential BSE risk to humans shows otherwise. The commenter stated that the risk modeling shows that there are two significant factors that contribute to the reduction in potential BSE risk to humans: (1) The amount of BSE infectivity in circulation (based on the number of BSE-infected cattle), and (2) compliance with SRM removal requirements. The commenter stated that the influence of the amount of BSE infectivity is demonstrated by the fact that when the 2005 risk model was updated to include the presence of BSE-contaminated poultry litter, resulting in more BSE-infected cattle, the effectiveness of SRM removal in reducing potential BSE risk to humans was decreased by nearly half (from 20 oral ID

50

s to 11oral ID

50

s)

6

even with perfect compliance with SRM removal requirements.

7

(BSE infectivity is expressed in terms of cattle oral ID

50

s. A cattle oral ID

50

is defined as the amount of infectivity required to cause infection in 50 percent of an exposed cattle population).

6

BSE infectivity is expressed in terms of cattle oral ID

50

s. A cattle oral ID

50

is defined as the amount of infectivity required to cause infection in 50 percent of an exposed cattle population.

7

The commenter cites Harvard Risk Assessment of Bovine Spongiform Encephalopathy Update, Phase IA, Supplemental Simulation Results, December 26, 2006, Appendix 2A, Section 2.1.2c, line 15 (AR 17464);

see also

Harvard Risk Assessment of Bovine Spongiform Encephalopathy Update, Phase IA, October 31, 2005, Appendix 2A, Section 2.1.2, line 15 (AR 17109).

The commenter stated that the authors of the risk models further substantiated that the amount of circulating infectivity impacts human health even with perfect compliance by explaining why the potential risk to humans was reduced following a simulation that prohibited SRMs from being used in both human food and animal feed. The commenter quoted the authors of the risk model as stating:

Removing infectious tissues from both human food and animal feed, assuming that the ban effectively covers dead stock, and assuming perfect compliance, together have a substantial impact on both the potential human exposure and the spread of BSE * * *. Potential human exposure decreases both because there are fewer BSE cases and because the measures remove infectious tissues from the human food supply. Average human exposure decreases by more than 99 percent from 3,800 cattle oral ID

50

s to 10 oral ID

50

s.”

8

8

The commenter cites the Harvard Risk Assessment of Bovine Spongiform Encephalopathy Update, Phase IA, October 31, 2005, at 29 (AR 17086).

Response:

The commenter appears to be attempting to use various model results to suggest that the SRM restrictions simulated in the models are not sufficient to mitigate the public health risk when there are higher numbers of infected animals present. However, the model results themselves do not support this conclusion. To discuss the commenter's statements in meaningful context, it is necessary to first provide a history of the models and model runs referred to.

In 2001, Harvard University provided USDA with the results of an extensive model that simulated the results of introducing BSE-infected cattle into the United States. This model has since been used and updated by both FSIS and APHIS at various times. These uses and updates include the following that are of significance and/or referenced in this docket:

• 2004—FSIS used model runs as part of their “Preliminary Analysis of Interim Final Rules and an Interpretive Rule to Prevent the BSE Agent from Entering the U.S. Food Supply.”

• October 2005—FSIS asked Harvard to update the model and run several simulations, and these were published for public comment “Harvard Risk Assessment of BSE Update; Phase IA, October 31, 2005.”

• December 2006—FSIS/Harvard incorporated changes based on public comment from the October 2005 simulations. This was made public, along with the responses to the public comments as “Harvard Risk Assessment of BSE Update; Phase IA; Supplemental Simulation Results, December 26, 2006.”

• September 2007—APHIS used the model, with amendments, as part of the risk assessment supporting its September 2007 final rule. The quantitative model was used to support the exposure assessment of the risk assessment.

In each of these instances, the assumptions used, the scenarios examined, and even the model itself differed from those in the others. It is therefore challenging to compare results from different instances of using the model without understanding the changes in the assumptions and the simulations. In the following paragraphs, we summarize these different model runs in chronological order and provide selected results from each, to help clarify the interpretation of the results.

2004:

In this instance, FSIS used a modified version of the 2001 Harvard BSE risk assessment model (as revised by Harvard in response to peer review comments). The baseline estimate assumed that five BSE-infected animals were imported into the United States in 2003. The model then simulated the spread of BSE infectivity until 2020. The analysis assumed that measures implemented in the United States to prevent the spread of BSE—e.g., the FDA feed ban—were in place at the time that infectivity was introduced. FSIS simulated the introduction of public health risk mitigation options—i.e., restrictions on SRMs and advanced meat recovery (AMR)—and assumed that these were implemented in 2004, 1 year after the infectivity was introduced. Therefore, because of these assumptions, the simulated mitigation options could never remove all of the infectivity that could be available for human consumption over the model simulation timeframe. In other words, BSE infectivity could enter the human food supply for 1 year before FSIS mitigations took effect. In the baseline analysis, with five infected animals introduced into the United States, over the 17-year simulation a mean of slightly less than two additional animals were affected. The baseline level of potential human exposure for the introduction of 5 infected animals—with no SRM risk mitigation options in place during the 17-year simulation—was an average of 22 cattle oral ID

50

s over the 17-year timeframe. With the introduction of SRM and AMR requirements (essentially the same requirements as those established by the FSIS regulations), the potential human exposure was an average of 7.5 cattle oral ID

50

s over the 17-year simulation. This was an 80 percent reduction in this simulation. Again, it is important to note that the public health assumptions used in these simulations could never remove more than 90 percent of the potential human exposure from the simulation.

In 2005 and 2006, FSIS again used the model to simulate a variety of risk mitigation options. The original simulations were published in October 2005 and public comment on the model and the assumptions used was invited. In response to the public comments received, some changes were made to the model and the assumptions, and the final results were published in December 2006. The base case in each of these simulations represented the circumstances in the United States prior to December 2003—i.e., with an FDA feed ban in place prior to the introduction of infected animals. In each scenario, 500 infected animals were introduced at one time and the model ran a total of 50,000 simulation runs for each scenario. The scenarios considered included various food safety measures, animal health measures (changes to the feed ban), and combinations of both.

The October 2005 model included the following results. The results of the base case simulation—500 infected animals and a simulation timeframe of 20 years—indicated a mean of 680 total infected animals over the 20 years (500 imported animals and 180 domestic animals) and a mean of 3,800 cattle oral ID

50

s potentially available for human consumption. In comparison, the scenario that modeled a comprehensive ban from human food of SRMs from cattle 30 months of age or older (which we refer to below as “30-month SRM restrictions”) yielded similar results for the number of infected animals, but with a mean of only 11 cattle oral ID

50

s potentially available for human consumption over the entire 20-year timeframe. The authors noted that they found that the food safety measures enacted by USDA all reduce potential human exposure to BSE infectivity but have little effect on spread of BSE in the cattle population. They also specifically noted that the results of the food safety measures enacted were relative reductions to what is already a small risk in absolute terms, especially in light of the fact that these simulations reflect the assumed introduction of 500 infected cattle into the United States. One other scenario modeled in this report was a removal of SRMs of animals 12 months and older (which we refer to below as a “12-month SRM restrictions”) from both the human and the animal food chain. This scenario decreased the number of infected animals to a mean of 540 total infected animals over the 20 years (including both imports and domestic cases) and indicated a mean of 9.8 cattle oral ID

50

s potentially available for human consumption. The authors conclude that this scenario indicates potential human exposure decreases both because there are fewer BSE cases and because the measures remove infectious tissues from the human food supply, although the amount of infectivity potentially available for human consumption (9.8 oral ID

50

s) was not significantly different from the simulation that modeled SRM removal (30 months of age and older) from only the human food supply. In other words, the number of BSE cases (680 total in the simulation with SRM removal from only human food as compared to 540 total in the simulation with SRM removal from both human and animal food chain) did not appear to significantly impact the potential human exposure.

The December 2006 model provided similar results in many ways. This report included a change to explicitly model contamination of cattle feed as a result of the recycling of poultry litter. The base case again simulated 500 infected animals introduced, with 50,000 simulation runs of 20-year timeframes. The base case results indicated a mean of 700 total infected animals over the 20 years (500 imported animals and 200 domestic animals), with a mean of 6,600 cattle oral ID

50

s potentially available for human consumption. Modeling a requirement for removal from the human food supply of SRMs from cattle 30 months of age or older, with 100 percent compliance, indicated a mean of 20 oral ID

50

s potentially available for human consumption over the 20-year time period. This same requirement, with an assumption of 99 percent compliance, indicated a mean of 83 oral ID

50

s potentially available for human consumption.

APHIS used a modified version of the Harvard model as part of the risk assessment that supported the September 2007 final rule. Specifically, we used the quantitative model in our exposure assessment to consider less likely scenarios. The model simulated BSE release and exposure in the United States over 20 years, with the introduction of infected animals from Canada at a constant rate over the entire period. We assumed that the existing FDA feed ban requirements were in place throughout the 20 years, and that FSIS and FDA restrictions on SRMs in human food were the same as implemented in 2004. The base case scenario results indicated that the importation of approximately 19 infected animals leads to approximately 2 U.S. cases as secondary spread, for a total of 21 infected animals over the 20-year period. The base case indicated a mean of 45 cattle oral ID

50

s potentially available for human consumption.

As noted above, the model results themselves do not support what seems to be the commenter's conclusion that the SRM restrictions simulated are not sufficient to mitigate the public health risk when there are higher numbers of infected animals present. Specifically, in the October 2005 model, both the base case and the 30-month SRM restrictions from human food indicated the same number of total infected animals—680 infected animals over the 20-year timeframe. Yet, the simulation modeling the 30-month SRM restrictions from human food reduced the mean amount of cattle oral ID

50

s available for human consumption from 3,800 to 11. In the scenario where 12-month SRM restrictions were applied in both human and animal food, although the number of total BSE cases changed (540 total infected animals), the amount of oral ID

50

s potentially available for human consumption (9.8 oral ID

50

s) stayed essentially the same as those in the 30-month SRM restriction scenario (11 oral ID

50

s). It should be noted that the assumptions used in the APHIS base case exposure assessment provided a total of only 21 infected animals over a 20 year time period—significantly less than the approximately 700 total infected animals in the FSIS simulations.

It is important to place some context around the results of the amount of infectivity potentially available for human consumption. The significance of cattle oral ID

50

s to human exposure and susceptibility is not known; however, various studies suggest that the infectious agent may be 10 to 10,000 times less pathogenic in humans than in cattle because of a species barrier (EC SSC, 2000). Thus, if the cattle-human species barrier were 100, it would mean that 100 times more infective material would be required in order to have a similar probability of infecting a human as a bovine. Comer and Huntly (2003) estimated, after an evaluation of available literature, that 54,000,000 (54 million) bovine oral ID

50

s were available for human consumption in Great Britain from 1980 to 2003. This extremely large amount of available infectivity has resulted in 168 cases of vCJD identified or suspected in the United Kingdom through March 2009, plus a few additional cases identified in other countries but attributed to exposure in the United Kingdom. When compared to the United Kingdom's BSE experience and the associated estimate of available bovine oral ID

50

s, the mean values of 11 potentially available cattle oral ID

50

s—

or even 20 oral ID

50

s or 83 oral ID

50

s—over a 20-year period are miniscule.

Issue:

One commenter stated that the prevalence of BSE in Canada is significantly higher than BSE prevalence in the United States and that APHIS has no basis to claim that measures implemented in the United States to mitigate the prevalence of BSE in this country are sufficient to mitigate a much higher prevalence in Canada. The commenter referenced a statement by the Centers for Disease Control (CDC) that the prevalence of BSE in Canada has been 90 percent likely to be between 18-fold and 48-fold higher than the previously published best estimate of the prevalence of BSE in the United States. The commenter stated that CDC notes that, nonetheless, a BSE prevalence in Canada 23-fold higher than that in the United States continues to be used in the Harvard Risk Assessments' “worst case” analysis when evaluating the risk of imported Canadian cattle's causing BSE to spread among U.S. animals.

Response:

In comparing the estimate of the prevalence of BSE in the United States with the estimated prevalence of BSE in Canada, it should be noted that the estimated number of BSE-infected animals per million is very low in either case—0.167 cases per million in the United States and 3 to 8 cases per million in Canada.

The commenter states that prevalence of disease has a significant impact on the effectiveness of mitigation measures, but provides no evidence to support this claim. Evidence in countries with significant outbreaks of BSE indicates that the animal health and public health mitigation measures are effective, even in the face of significantly higher prevalence levels. The primary animal health mitigation measure is a feed ban to prevent the inclusion of potentially infective tissues from being fed to cattle. This measure has demonstrably worked in the United Kingdom, a country with a significantly higher prevalence level relative to other countries. The number of BSE cases identified in birth year cohorts (all cattle born in a given year) in the United Kingdom has continued to decline since peaking in 1987. The United Kingdom established its initial feed ban requirement in 1988. This continuous decline clearly demonstrates the effectiveness of a feed ban as an animal health mitigative measure in the face of an outbreak with high prevalence. Similarly, on the public health side, SRM restrictions are an effective public health measure, even in a high prevalence situation. Experience in the United Kingdom and elsewhere in Europe demonstrates this effectiveness. The models used by FSIS that are discussed above continue to indicate the effectiveness of this measure, even when simulating relatively high numbers of infected animals present in the system. Given all of these points, APHIS has no reason to believe that the effectiveness of these mitigation measures is impacted by differences in prevalence levels.

Issue:

One commenter stated that it is important to note that APHIS' estimate of the prevalence of BSE in Canada is based on the detection of 11 cases of BSE, and that since that estimate was made, additional cases of BSE in Canadian cattle have been diagnosed. The commenter stated that APHIS should not rely on outdated prevalence estimates to evaluate Canada's BSE risk.

Response:

In conducting our assessment of the risk of importing live bovines from Canada under the provisions of the 2007 final rule, we took into account, among other factors, the estimated prevalence of BSE in Canada. In discussing our estimate of BSE prevalence in Canada in that final rule, we explained that the number of BSE cases detected through surveillance understates the disease prevalence because exposed animals may be incubating disease and carrying infectious material in their tissues without presenting clinical symptoms. We noted, additionally, that surveillance will miss a proportion of detectable cases. Therefore, as we explained in our 2007 final rule, we applied statistical methods to the available epidemiologic and surveillance data to estimate, with attendant uncertainty, the prevalence of BSE in Canada. Even taking into account this attendant uncertainty, our qualitative and quantitative assessments of release of BSE into the United States via the import of live bovines from Canada demonstrate an extremely low likelihood of release, and that, because of the comprehensive mitigations already in place in the U.S., the likelihood of establishment is negligible.

Issue:

One commenter noted that the epidemiological investigation conducted by Canada regarding an animal born in 2003 indicated that the most likely source of infection was consumption of commercial cattle feed produced in Canada. The commenter concluded that such information demonstrates that what the commenter termed “Canada's widespread BSE exposure” occurred because the August 1997 feed ban in Canada failed to address the cross-contamination of cattle feed with feed produced for other animals.

The commenter stated that APHIS' statement that its 2005 evaluation of the feed ban in Canada revealed that overall compliance with the feed ban is good and that the feed ban was reducing the risk of transmission of BSE in the Canadian cattle population has been disproven by subsequent outbreaks of BSE in cattle that were born years after the implementation of Canada's feed ban. The commenter stated further that the CDC has reported that occurrence of BSE in Canada has risen in recent years.

The commenter stated that there is no evidence that the prevalence of BSE in Canada is decreasing at this time. The commenter noted that most of the animals diagnosed with BSE in Canada were born after Canada implemented its 1997 feed ban and that over half of those cases were born after March 1, 1999, the date that APHIS determined to be the date of effective enforcement of the feed ban in Canada. The commenter also noted that more animals determined to be infected with BSE—two—were born in 2000 than in any other year. Other commenters also expressed opposition to the removal of the delay of applicability of the provisions described above because of the diagnosis of BSE in a number of Canadian-born cows since the diagnosis of BSE in a Canadian-born cow in May 2003. Some commenters expressed particular concern regarding the discovery of BSE in Canadian cattle within the past several years. One commenter stated that Canada's feed ban was not made whole until July 2007, when Canada took steps to ban ruminant protein from all animal feed and fertilizer. The commenter concluded that USDA should withdraw the September 2007 final rule and initiate a rulemaking to determine if Canada's feed ban is likely to have become effectively enforced after July 2007.

Response:

We disagree with the commenters' conclusions. The commenters suggest that, in order for the Canadian feed ban to be considered effective, BSE surveillance data would have to demonstrate that the likelihood of BSE transmission in that country has been eliminated. However, as noted in the risk assessment for our September 2007 final rule, Canadian BSE surveillance data do not provide a statistical basis for distinguishing BSE prevalence among birth year cohorts (APHIS, 2007); the overall prevalence is so low that distinguishing any difference is nearly impossible. In other words, the data cannot distinguish any significant difference in prevalence among animals born in different years, which would have been one way to demonstrate the effect of a feed ban

(e.g., if the feed ban were implemented at the beginning of 1997, surveillance data showing a higher BSE prevalence in animals born in 1996 than in animals born in 1997 would support the effectiveness of the feed ban). However, in the absence of a feed ban that reduced exposure to BSE, we would expect the prevalence of the disease to increase over time. We have no evidence that such an increase has occurred but we do have data that the feed ban is being enforced.

Furthermore, as we discussed in the risk assessment for our September 2007 final rule, detection of BSE in an animal born after the date a feed ban was implemented does not indicate an overall failure of the measures in place to stem transmission of the disease in that country. Most other countries that have experienced cases of BSE have reported similar cases. Human error is expected, which is why the feed ban is comprised of a number of interrelated measures that have a cumulative effect. Our risk assessment does not assume 100 percent compliance with all measures all of the time. We discussed factors related to the feed ban in Canada since before its implementation in 1997. We considered activities related to inspection and compliance with the feed ban, the rendering industry, the risk of cross-contamination, education activities and industry awareness, and on-farm practices that might contribute to the efficacy of the feed ban. In addition, we highlighted the fact that since the implementation of the feed ban on August 4, 1997, Canada has continued to revise and strengthen its processes and procedures to further enhance the effectiveness of the feed ban.

With regard to the commenter's recommendation that a date in July 2007 be considered as the date of effective enforcement of a feed ban in Canada, as we discussed in our September 2007 final rule, we consider the July 2007 expansion of the Canadian feed ban to be an enhancement of an already effective ban. In July 2007, Canada modified its feed ban to remove SRMs from all animal feeds, pet food, and fertilizer. CFIA, in explaining its rationale for the enhanced ban, emphasizes that although surveillance results and investigations of BSE cases indicate that the feed ban in Canada has effectively reduced the spread of BSE since being implemented in 1997, even compliance with the ban's requirements left limited opportunities for contamination during manufacture, transportation, and storage that CFIA considered worth eliminating. In addition, the accidental misuse of feed on farms with multiple species could not be discounted. With the enhanced ban, CFIA projects that the eradication of BSE in Canada will be accelerated. Following such a regulatory path does not indicate that the feed ban in Canada prior to July 2007 was not effective or effectively enforced.

Issue:

One commenter stated that APHIS, in its September 2007 final rule, established that SRM removal requirements are approximately 19 percent less effective in preventing human exposure to the BSE agent when those requirements are applied to cattle born before effective BSE mitigation measures were in place, such as in cattle born before the Canadian feed ban became effective.

The commenter discussed analyses that were conducted by FSIS to estimate the likely reduction of potential human exposure to BSE given the SRM removal requirements established by that Agency. The commenter stated that, in its 2004 evaluation, FSIS estimated that the SRM removal policy adopted by that Agency could reduce potential human exposure to BSE by 80 percent, based on the assumption that five BSE-infected animals had been introduced into the United States 12 months before FSIS implemented its BSE mitigation measures, including SRM removal. In 2005, stated the commenter, FSIS re-analyzed the likely reduction in potential human exposure, this time assuming that U.S. risk mitigation measures were implemented before the introduction of BSE-infected cattle in the United States. Using that assumption, said the commenter, FSIS indicated that the mitigation measures implemented by FSIS in 2004 would reduce potential human exposure by more than 99 percent on average. APHIS discussed the results of this re-analysis in its September 2007 final rule, stating:

“Since all scenarios [evaluated by FSIS] included at least some time in which the mitigations were not implemented, under the simulations, a certain amount of potential infectivity was allowed into inappropriate channels, such as human food. Because none of these scenarios incorporated the more realistic assumption that the mitigations were implemented (even imperfectly) throughout the simulation period, it is inappropriate to use this analysis as a citation for the level of public health protection provided by risk mitigation measures in place in the United States.

A more appropriate analysis for understanding the role of SRM removal in potential human exposure to BSE infectivity would be the FSIS update of the same Harvard simulation model that was available for public comment in 2006 * * *. This updated model used the “base case” as the circumstances in the United States prior to December 2003, and simulated the response of the U.S. system for 20 years following the import of BSE-infected cattle. FSIS' updated model estimated the impact of various risk management measures, including measures that were adopted, considered, or proposed by various agencies and groups. These simulations, where the risk mitigation was applied during the entire simulation, as opposed to the simulation in the [2004] analysis * * * (in which it was not), indicated that removing SRMs, as currently defined by FSIS, reduced potential human exposure by more than 99 percent, on average. This report also stated that “[i]t is worth noting that these measures reduce what is already a small exposure in absolute terms.” (72 FR 53335-53336)

The commenter stated that the latter FSIS analysis is irrelevant to the issue of risk related to the importation of beef from Canada derived from cattle 30 months of age or older, because Canada is known to have had at least three generations of BSE infectivity in its native cattle herd prior to the time that Canada implemented its BSE mitigation measures, including SRM removal.

Response:

The commenter states that APHIS established that SRM removal requirements are approximately 19 percent less effective in preventing human exposure to the BSE agent when those requirements are applied to cattle born before effective BSE mitigation measures were in place, such as in cattle born before the Canadian feed ban became effective. However, APHIS did not establish or suggest such a conclusion. In our September 2007 final rule, we responded to a commenter who raised the issue of the FSIS 2004 model, where the potential human exposure was reduced by only 80 percent. APHIS explained that this specific use of the model was not appropriate in completely evaluating the role of SRM removal in potential human exposure and noted that the FSIS 2005/2006 simulations provided a better analysis for understanding potential human exposure. APHIS noted that the FSIS 2004 model included “* * * at least some time in which the mitigations were not implemented * * *” (72 FR 53336). The commenter appears to have interpreted this to include all mitigations, including animal health mitigations such as the feed ban. This is inaccurate, as the FSIS 2004 model assumed that the feed ban requirements were in place throughout the 17-year time period of the simulations.

The commenter suggests that use of the FSIS 2005 model is inappropriate in an evaluation of the risk of imported beef from Canada, because Canada had infectivity in its cattle herd for at least three generations prior to implementing SRM restrictions. The commenter is

correct that the timeframe of implementing SRM restrictions is important for public health considerations. However, the commenter's conclusion that the presence of infectivity in animals prior to the implementation of SRM restrictions affects the effectiveness of those SRM restrictions is inaccurate. Requirements to prevent the inclusion of SRMs in the human food supply provide an immediate public health impact, regardless of the length of time infectivity may have been present in animals. These restrictions prevent infectious tissues from any animal—born before or after a feed ban—from entering the human food supply. As demonstrated in the FSIS 2005 and 2006 models, they provide significant public health protection, even over a 20-year timeframe.

Issue:

The commenter stated that APHIS has provided no basis for an assertion that the rate of compliance with SRM removal requirements for Canadian cattle slaughtered in either the United States or Canada is adequate to protect human health. The commenter stated that the influence of the extent of compliance with SRM removal requirements is demonstrated by that fact that, all else being equal, when compliance with SRM removal requirements drops by only 1 percent, the potential risk to human health is more than quadrupled (increasing from 20 oral ID

50

s to 83 oral ID

50

s).

Response:

We disagree that APHIS has not provided a basis for its conclusion that SRM removal in the United States or Canada constitutes an effective safeguard of human health with regard to BSE. In our September 2007 final rule, we established conditions for the importation into the United States of live bovines born on or after the date of effective enforcement of a ruminant-to-ruminant feed ban in a BSE minimal-risk region, as well as conditions for the importation of other bovine-derived commodities. As part of that rulemaking, we conducted an assessment of the potential BSE risk of implementing the provisions of the final rule. The exposure model used for the risk assessment assumed that SRMs are effectively removed 99 percent of the time in the United States. This assumption was based on FSIS summaries of Noncompliance Records performed from January 2004 to May 2005 in about 6,000 federally inspected meat and poultry establishments. Based on these records, FSIS estimated that noncompliance with respect to SRM-related regulations had a frequency of less than 1 percent.

In our September 2007 final rule, we explored the possible impact of assuming an arbitrary decrease (compared to the results of our exposure model) in SRM removal compliance in the United States on the availability of infectivity for human consumption. The model was for the United States, not Canada, but based on similarities in slaughterhouse practices in the United States and Canada, we can make a broad general assumption that the results in Canada would be the same as those in the United States. As discussed earlier in this document, in a 2007 audit in Canada, FSIS specifically assessed controls for SRM removal in Canada and identified no related deficiencies.

In our September 2007 final rule, we discussed the significance of an order-of-magnitude increase in available infectivity compared to our model's findings. First, we considered the results of that model, which uses the unlikely assumption that prevalence in Canada (and thus the proportion of infected animals imported from Canada) remains constant over the next 20 years. In the model's scenario, the total amount of infectivity potentially available for human consumption over the 20 years of the analysis is 45 cattle oral ID

50

s.

As discussed above, if the cattle-human species barrier were 100, it would mean that 100 times more infective material would be required in order to have a similar probability of infecting a human as a bovine. As noted, the extremely large amount of infectivity available for human consumption in Great Britain from 1980 to 2003—estimated by Comer and Huntly (2003) as 54 million bovine oral ID

50

s—resulted in 168 cases of vCJD identified in the United Kingdom through March 2009, plus a few additional cases identified in other countries but attributed to exposure in the United Kingdom. As discussed above, when compared to the United Kingdom's BSE experience and the associated estimate of available bovine oral ID

50

s, the expected or average value of 45 cattle oral ID

50

s indicates that only a miniscule amount of the BSE infective agent could possibly be available for potential human exposure in the United States over a 20-year period. (The potential for human exposure under this scenario is estimated at 1,200,000 times less in the United States than what the United Kingdom experienced during its BSE epidemic.) Even if compliance with the SRM ban were not as high as the 99 percent estimated in our exposure model, and we were to assume that the infectivity available for human consumption were increased by an order of magnitude (10x), it would still be far less than that estimated to have circulated in the United Kingdom and, we conclude, not be of significance to human health.

Issue:

One commenter noted that APHIS stated in its September 2007 final rule that effective enforcement of a ruminant-to-ruminant feed ban does not necessarily mean 100 percent compliance with the feed ban will be achieved. The commenter stated that, although APHIS concludes that removal of SRMs effectively mitigates the BSE risk to humans associated with cattle that pass both ante-mortem and post-mortem inspections, FSIS states that this conclusion regarding the effectiveness of SRM removal is valid only if compliance is perfect. The commenter stated that it is arbitrary and capricious for APHIS to conclude that a feed ban is effective and effectively enforced even without perfect compliance, while at the same time concluding that SRM removal requirements provide effective mitigation to human health, even though such a level of protection is predicated on perfect compliance.

Response:

We disagree with the commenter's logic. There are multiple mitigation measures that contribute to reduction of BSE risk. Each has its own degree of importance in a systemic reduction in risk. As we discuss above, enforcement of an effective feed ban in a region has the effect of reducing the amount of circulating BSE infectivity in that region. This makes it less likely that any one animal in that region will be infected with BSE. SRM removal is a method of removing and disposing of tissues that present a high likelihood of containing BSE infectivity if an animal were infected. In effect, countries such as the United States, Canada, and other countries worldwide that require SRM removal are making the assumption that any one animal presented for slaughter could be infected with BSE, even though the presence of an effective feed ban in that country reduces the likelihood of that to a minimal level.

With regard to the text from the FSIS document regarding perfect compliance, it is important to review the wording cited by the commenter in context. In the FSIS interim rule referred to by the commenter, FSIS refers to the December 2006 model we describe above, and states the following:

However, although both the number of BSE cases and the level of human exposure increased in the post-public comment runs, conclusions with regard to prohibiting the use of SRMs for human food remain the same. More specifically, even with the revised base case, the post-public comment

runs show that excluding the materials designated as SRMs in this final rule almost completely eliminates potential human exposure to the BSE agent if compliance is perfect. Similarly, the post-public comment runs found that neither lowering the age classification for SRMs from cattle 30 months of age and older to 12 months of age and older, nor from 30 months of age and older to 24 months of age and older, provides additional benefits in reducing the level of potential human exposure to the BSE agent. Thus, the results of the 2005 model, regardless of the base case used, have not led the Agency to change its conclusion that the measures adopted in this final rule are prudent for preventing potential human exposure to the BSE agent. (72 FR 38726)

In addition, in the same rule, FSIS refers to the October 2005 model we described above, and states the following: “The pre-public comment runs found that removing SRMs from cattle 30 months of age and older almost completely eliminates potential human exposure, reducing it to 11 cattle oral ID

50

s * * *. It is worth noting that these are relative reductions to what is already a small risk in absolute terms, especially in light of the fact that these simulations reflect the assumed introduction of 500 infected cattle into the U.S.” (72 FR 38725)

FSIS considered all of the information from the modeling simulations, including those runs where compliance was assumed to be less than 100 percent. Evaluating all of these results and statements together demonstrates the overall conclusion that SRM removal effectively mitigates the BSE risk to humans.

We also note that APHIS did not assume 100 percent compliance with SRM removal in the exposure assessment of our risk assessment. As noted elsewhere, we assumed a 99 percent compliance rate, acknowledging that no regulatory effort can ever ensure 100 percent compliance.

Specified Risk Materials

One of the requirements for the importation of meat, meat byproducts, and meat food products derived from bovines in BSE minimal-risk regions is that the SRMs of the bovines were removed at slaughter. In §§ 94.0 and 95.1 of the regulations, SRMs are defined as “[t]hose bovine parts considered to be at particular risk of containing the bovine spongiform encephalopathy (BSE) agent in infected animals, as listed in the FSIS regulations at 9 CFR 310.22(a).” With some limited exceptions, the FSIS regulations list the following tissues as SRMs: (1) The brain, skull, eyes, trigeminal ganglia, spinal cord, vertebral column (excluding the vertebrae of the tail, the transverse processes of the thoracic and lumbar vertebrae, and the wings of the sacrum), and DRG from cattle 30 months of age and older, and (2) the distal ileum of the small intestine and the tonsils from all cattle. If the small intestine is to be used for human food, the distal ileum must be removed by a procedure that removes at least 80 inches of the uncoiled and trimmed small intestine as measured from the ceco-colic junction and progressing proximally towards the jejunum, or must be otherwise removed by a procedure that the establishment demonstrates is effective in ensuring complete removal of the distal ileum.

Issue:

One commenter stated that central to APHIS' September 2008 request for comments is the Agency's assumption that SRM removal will effectively protect consumers from exposure to BSE. The commenter stated that such an assumption is called into question by numerous studies demonstrating the limitations on mitigating the risk of BSE exposure via SRM removal. The commenter stated that the CDC has acknowledged that the risk of humans developing vCJD from eating muscle meat from cattle potentially infected with BSE cannot be precisely determined. The commenter stated that APHIS should have, but has not, explained why this uncertainty does not undermine what the commenter termed APHIS' almost-exclusive reliance on SRM removal requirements to protect American public health from potentially hazardous Canadian imports.

The commenter stated that the current inability to detect BSE prions in certain tissues does not mean that there is insufficient infectivity to be a hazard and that, while BSE prions have been found only in a solitary bovine muscle of a single cow, that likely is a function of the current limited analytical sensitivity of the test. The commenter stated that all the other information points to the likelihood that prions are present in such tissues.

The commenter stated that APHIS ignores the significance of recently detected BSE variations and dismisses the relevance of new studies that have detected BSE infectivity in new tissues. The commenter stated that in its September 2008 request for comments, APHIS stated that the new findings could be the result of more sensitive tests and of detection tools that may over-express the BSE agent. The commenter stated that APHIS incorrectly argued in its September 2008 request for comments that, because demonstrating the presence of PrP does not necessarily indicate the presence of BSE infectivity, studies that have detected abnormal PrP in the facial and sciatic nerves do not warrant new mitigation measures. The commenter stated that the World Health Organization (WHO) has found both the presence of Prp

TSE

and BSE infectivity in the peripheral nerves of cattle. The commenter stated that the WHO has identified two classifications of BSE tissue infectivity, “high infectivity” and “lower infectivity,” and that the WHO includes peripheral nerves (e.g. sciatic and facial nerves) in the category of lower infectivity.

The commenter stated that, in its request for comments, APHIS specifically cited research that detected BSE infectivity in the sciatic nerve of cattle, but only after 30 months after exposure. Despite this, stated the commenter, APHIS does not require mitigation measures regarding the sciatic nerve in cattle 30 months of age or older. The commenter stated that facial and sciatic nerves are the only bovine tissues scientifically determined by multiple studies to harbor BSE infectivity for which APHIS requires no risk mitigations, not even the mitigation of requiring that beef imported from Canada be derived only from cattle that were subject to a feed ban during their lifetimes. The commenter stated that this policy is inconsistent with APHIS' consideration of tonsils in cattle of any age as an SRM tissue, even though APHIS cites only one study that found what appears to be a very low level of infectivity in the tonsils of BSE-infected cattle.

The commenter disagreed with this policy, stating that (1) BSE infectivity is known to exist in non-SRM tissues; (2) BSE infectivity is known to have been circulating in Canadian cattle for years, leading up to and including 2003; and (3) APHIS does not know the minimum dosage necessary to cause BSE infectivity in either humans or cattle. The commenter cited 2006 WHO guidelines as stating: “It remains unknown whether tissues containing such very small amounts of infectious material [detected by novel techniques] would transmit infection to humans.” (The commenter cites WHO Guidelines on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies, World Health Organization, 2006, at 10.) Based on this uncertainty, stated the commenter, APHIS should take precautionary steps to avoid human exposure to meat and meat products from Canadian cattle that pose the highest risk of infection— cattle 30 months of age or older— particularly those born before the Canadian feed ban was effective.

Response:

A similar issue was raised by the commenter in response to our January 2007 proposed rule. We are aware of the studies cited by the commenter and do not agree that they question the efficacy of SRM removal. In our September 2007 final rule, we acknowledged that studies using new methods that provide increased sensitivity will probably demonstrate the presence of PrP

BSE

(the abnormal form of the prion protein) in various tissues. However, demonstrating the presence of PrP

BSE

does not necessarily indicate the presence of BSE infectivity, especially if no infectivity is demonstrated via the most sensitive method available: Cattle-to-cattle exposure via intracerebral transmission. Therefore, one cannot automatically assume that a finding of PrP

BSE

in a tissue means the tissue should be defined as an SRM. The OIE made this particular point in the

Terrestrial Animal Health Standards Commission Report, October 2006—Supporting Document for Chapter 2.3.13. Of the Terrestrial Animal Health Code on Bovine Spongiform Encephalopathy,

as follows:

The availability of experimental infectivity data has significantly increased in recent years. During the same interval, extremely sensitive tests have been developed, including those employing highly sensitive transgenic mice strains and potentially more sensitive laboratory PrP detection methods. With the development of such highly sensitive methods, the probability of detection of PrP

BSE

in tissues that are not currently listed as infectious is increasing. However, such findings need to be considered in context, and their relevance to establishing risk to consumers evaluated carefully when the quantity of PrP

BSE

detected is potentially below the limit of detection of intracerebral (i.c.) cattle to cattle bioassay. By April 2007, 165 variant Creutzfeldt-Jakob Disease (vCJD) cases had been detected in the United Kingdom, a country where most probably the majority of the population was exposed to the BSE-agent. The latest models of the vCJD epidemic estimate that the potential scale of the clinical epidemic arising from food-borne exposure is unlikely to exceed 400 future cases in the United Kingdom (Clarke and Ghani, 2005). The relatively low number of predicted vCJD cases in relation to the massive exposure to the BSE agent is suggested to be due mainly to a significant species barrier between cattle and humans (Comer and Huntley, 2004; Bishop

et al.,

2006).

APHIS is familiar with the results of the study (Buschmann, 2005) in which tissues from a BSE-diseased cow were inoculated into genetically engineered (transgenic) mice that are highly susceptible to BSE and that overexpress the bovine prion protein. Using this extremely sensitive mouse assay, the study demonstrated low levels of infectivity in the peripheral nervous system (e.g., facial and sciatic nerves) of the infected cow. APHIS discussed these findings in the risk assessment it made available with its September 2007 final rule and concluded that “[g]iven all these factors there is not sufficient information to alter our understanding of the epidemiologically significant distribution of BSE infectivity in cattle.” (APHIS, 2007). APHIS also acknowledges the results of Japanese studies in which PrP

BSE

has been reported in the peripheral nerves of a case of BSE (Iwamaru

et al.,

2005) and in some peripheral nerves of cattle slaughtered at abattoirs in Japan (Iwata

et al.,

2006) by Western blot analyses. APHIS has also reviewed the German study in which infectivity was detected in the brainstem of an animal at 24 months post-infection (Hoffman, 2007). We have carefully considered all of these findings. USDA reviews and takes into consideration all BSE research for the definitions of SRMs, as do Canada and other countries internationally. As noted in the quote above, international policies regarding SRM removal have not changed based on the results of the studies discussed. Both the U.S. and Canadian policies regarding SRM removal are consistent with international standards.

Finally, we consider the quote the commenter provides from the WHO 2006 report to be of little use when presented out of context. In the report referenced by the commenter, the WHO was discussing in a hypothetical fashion the possibility of advances in techniques to detect PrP

TSE

not limited to PrP

BSE

. The WHO statement reads as follows:

Several new methods attempting to detect PrP

TSE

using novel techniques * * * if successfully developed, might eventually offer sufficient sensitivity to demonstrate amounts of agent below the level of detection of currently validated tests. It has been speculated that such methods might find small amounts of agent in some tissues currently thought to be free of infectivity. It remains unknown whether tissues containing such very small amounts of infectious material would transmit infection to humans. (WHO, 2006)

Issue:

One commenter stated that APHIS' assumption that removal of the tonsils removes the potential for BSE transmission is unjustified given that APHIS has not evaluated the potential for contamination of tongue with tonsil tissue. The commenter stated that, although APHIS claims the possibility of such contamination is eliminated by current slaughter techniques, scientists who examined over 250 bovine tongues intended for human consumption found tonsillar tissue in the vast majority; in some cases, even after the most rigorous trimming of the root of the tongue.

9

9

The commenter cites Wells, G., Spiropoulos, J., Hawkins, S., and Ryder, S., Pathogenesis of Experimental Bovine Spongiform Encephalopathy; Preclinical Infectivity in Tonsil and Observations on the Distribution of Lingual Tonsil in Slaughtered Cattle,

Veterinary Record

(2005) 156, 401-407.

Response:

We are making no changes based on the comment. As we discussed in our September 2007 final rule, Wells

et al.

(2005) state the following:

However, the trace level of infectivity so far detected in tonsillar tissue and the localization of the lingual tonsillar lymphoid tissue, together with the current SRM legislation for the removal of tonsil from cattle carcasses and the low and diminishing prevalence of BSE in the UK suggest that the risk of human exposure to infected tonsil is now remote. It seems likely that under these circumstances any additional trimming of the tongue would result in an immeasurable reduction in the risk * * *

In other words, the study cited by the commenter does not present a strong case for additional risk measures, and, in fact, points to the opposite conclusion.

Moreover, even before the SRM requirements were implemented in January 2004, FSIS did not consider tonsil to be edible tissue—it was previously required to be removed. As noted in FSIS Notice 50-04:

In the preamble to 9 CFR 310.22, FSIS stated that tonsils of all livestock species, including cattle, were already required to be removed and were prohibited for use as ingredients in meat food products under 9 CFR 318.6(b)(6). The accepted practice for removing the tonsils from livestock has been to remove all visible tonsils. In cattle, this includes separation of the palatine tonsils and lingual tonsils from the tongue (in establishments that harvest the tongue for human food) by a transverse cut caudal (just behind) the last vallate papillae * * * FSIS expected that establishments would continue to remove tonsils from cattle in accordance with the procedures that they had implemented to comply with 9 CFR 318.6(b)(6) * * * Establishments that slaughter cattle should have been following these practices before tonsils were designated as SRMs. (FSIS, 2004c).

APHIS' quantitative exposure model conducted for the September 2007 final rule included an update that acknowledged the potential infectivity in tonsils and clearly added these as an SRM, with the acknowledgment that they could still be potentially available for human consumption. In fact, the output tables from the model runs show the potential oral ID

50

s derived from tonsils and available for human consumption over the 20-year period of

the analysis. These values are obviously very low, ranging from 0.026 oral ID

50

s in the base case scenario to 0.16 oral ID

50

s in sensitivity analysis 6 (in which all uncertain parameters were simultaneously set to their corresponding pessimistic level). Such very small values are not surprising given the low likelihood of infectivity in the tissue itself. Moreover, although our model predicts a vanishingly low level of possible human exposure via tonsils, we have not stated that the risk is “eliminated,” as was suggested in the comment.

Issue:

One commenter stated that it is not yet possible to demonstrate how effective SRM removal is in mitigating the risk of BSE, because SRM removal requirements have not been in place long enough for an effect to be evident, particularly in light of the lengthy incubation periods assumed for vCJD in humans. The commenter stated that any human who consumed beef from a BSE-infected animal slaughtered after SRM removal requirements were implemented would not be expected to show signs of vCJD for about 17 years. The commenter stated that, if there has been a reduction in the number of cases of vCJD infection—which the commenter said is unclear—it is much more likely that that the reduction resulted from decreases in the number of infected cattle in the past decade due to feed bans, rather than to what the commenter termed the much more recent implementation of SRM removal.

Response:

The commenter raised a similar issue in response to our January 2007 proposed rule. In response to the comment, we acknowledged in our September 2007 final rule that there has been no specific controlled study that clearly and unequivocally demonstrates the effectiveness of SRM restrictions on protecting public health. However, the absence of such a study does not negate the fact that substantial epidemiological and case evidence clearly indicate the success of such control measures. As we stated in our September 2007 final rule, it is widely and generally accepted internationally, including by such international bodies as the WHO and the OIE, that the primary public health protective measure regarding BSE is the removal of SRMs from the human food supply (WHO, 2002).

The OIE Scientific Revue notes the following: “Excluding SRM from the human food chain effectively minimizes the risk of human exposure and is the most important measure taken to protect consumers. Failure to remove SRMs would probably expose a large number of consumers to an unnecessary risk.” (Heim and Kihm, 2003). This point is also widely acknowledged in scientific literature. For example, Bradley and Liberski (2004) conclude that “risks to humans from infected cattle are now remote so long as the [bans on the use of SRMs in human food] are rigorously enforced.” Fox and Peterson (2004) conclude that “[a]doption of the human [specified bovine offal] ban in the United Kingdom in 1989 is probably the only example in the BSE story of a government going beyond expert opinion in taking a precautionary measure. It turned out to be the correct decision, and likely saved thousands of people from exposure to the disease.”

Simulation models and analysis conducted in the United Kingdom support the assumption that primary exposure sources for people were SRMs in the food supply prior to imposed restrictions. These models have been updated and revised repeatedly since the original identification of vCJD and the link to BSE in cattle (Ghani

et al.,

1998, 2000, 2001, 2003). They incorporate assumptions for all the parameters that could influence the course of vCJD in the United Kingdom—including assumptions about primary exposure from dietary sources, calculations about how many infected cattle may have been slaughtered at different points in time, what tissues from those animals were available for consumption, and what restrictions were imposed on the tissues and types of products available for consumption. The models are updated routinely to incorporate new information about vCJD cases as they are reported.

These models have been used to predict the course of the vCJD epidemic in the United Kingdom. Initially, the projections were fairly high with considerable uncertainty. As more information is incorporated into the models, these projections continue to decline and the uncertainty levels also decrease. The number of clinical cases of vCJD in the United Kingdom has continued to decline since an apparent peak in 2000 (Andrews, 2007). This decline is consistent with projections made from the models, thus validating some of the assumptions used in the models. As an example, Cooper and Bird (2003) assume that the primary sources of exposure are the consumption of meat products—including mechanically separated meat and head meat-that were most likely contaminated with SRMs such as spinal cord, DRG, and brain. Restrictions on the inclusion of spinal cord and brain, among other tissues, were initially imposed in the United Kingdom in 1989. Restrictions on the production of mechanically separated meat, which included a significant level of infectivity from DRG, were imposed in the United Kingdom in 1995. Cooper and Bird (2003) concluded that “[t]here is remarkable similarity between the age distribution and gender of simulated and observed vCJD patients, which supports (but does not prove) our assumption about the primary sources of exposure to BSE.”

The commenter noted the “exceedingly long incubation periods assumed for humans.” More recent updates of the models described previously have included estimates of the mean incubation period for vCJD (Ghani

et al.,

2003), estimating the mean incubation period at 12.6 years when using the accumulated case data from confirmed vCJD cases. When additional information was added from results of a screening study performed on appendix and tonsil tissues, the mean incubation period was 16.7 years when fitted to this data. From this evidence, we can conclude that even the longer mean incubation period of 16.7 years would allow sufficient time to demonstrate the effect of SRM restrictions on the outbreak, since the initial SRM restrictions were imposed in 1989. We note that all vCJD cases that have been genotyped to date, with one exception, have been of the homozygous methionine (MM) genotype at codon 129 of the human prion protein gene. In describing the methodology used for their 2003 update of projections of future vJCD cases in the United Kingdom, Ghani

et al.

indicated that approximately 40 percent of the Caucasian population is homozygous methionine, with approximately 10 percent valine homozygous, and the remaining 50 percent heterozygous. While the effect of genotype on vCJD is still unknown, we can evaluate scenarios in the MM genotype as an example of epidemic progression, because this genotype may be the most susceptible and/or have shorter incubation periods than other genotypes.

Issue:

One commenter stated that, in its September 2008 request for comments, APHIS misguidedly relied on OIE recommendations to justify its decision not to strengthen SRM removal requirements and to allow the importation from Canada of live cattle 30 months of age or older. The commenter stated that APHIS should base its assessment of the effectiveness of BSE mitigation measures on empirical data from countries that have imposed BSE restrictions, rather than on empirically unproven standards such as those recommended by the OIE.

The commenter stated that Japan allows the importation of beef only from cattle 20 months of age or younger and that the European Union limits imports of beef to that derived from cattle under 30 months of age.

The commenter stated that all countries in which BSE has been diagnosed, except for Canada, remove the brain, spinal column, etc., at slaughter from all bovines 12 months and over, rather than just from all bovines 30 months of age or older, as is required by APHIS for the importation of meat, meat byproducts, and meat food products from BSE minimal-risk regions. The commenter noted that Japan requires the removal of SRMs from cattle of any age. Therefore, stated the commenter, the experience with SRM removal in those countries is inapplicable for predicting risk in the United States and APHIS lacks a basis for stating that the SRM removal it requires has been demonstrated to be highly effective.

Response:

We disagree with the commenter in several ways. First, contrary to the commenter's statement, the European Union has determined that its policies regarding the importation of beef are consistent with the OIE Code. Second, the commenter failed to list the United States as a country in which BSE has been diagnosed in a native animal that requires removal of the brain, spinal column, etc., at slaughter from bovines 30 months of age or older. Finally, the commenter's recommendations are inconsistent with scientific findings regarding BSE transmission generally accepted internationally.

As we noted in our September 2007 final rule, in the past few years, significant consideration has been given to the age limits on SRMs and their appropriateness. Additional information obtained from new research findings has contributed to these evaluations. Scientists in Europe have specifically examined these findings as part of their consideration of the age limit in cattle for the removal of SRMs (EFSA Journal, 2005; 2007). In each of these opinions, they conclude that any likely detectable infectivity in the central nervous system (CNS)—including the SRMs in question—appears at about 75 percent of the incubation time. These opinions also note that the experimental low-dose scenarios are more likely to resemble the actual field exposure. The low-dose research scenarios are those in which calves were exposed orally to 1 gram of highly infective brain tissue, rather than the 100 grams used in the high-dose scenario. Experimental attack rate studies indicate that the incubation period for the low-dose scenario has a mean of 60 months, with a range of 45 to 73 months (Wells

et al.,

2007). Using the low end of this range of incubation period, and assuming that infectivity is present in the CNS at 75 percent of the incubation period, they predict that infectivity would be sub-detectable or still absent in CNS in cattle aged 33 months.

In the United Kingdom, even including cases from the height of the BSE epidemic there, which are believed to have had shorter incubation periods than more recent cases, the peak age at onset of clinical signs was 5 to 6 years. This age of clinical onset is consistent with an assumption that the average incubation period in the United Kingdom has been about 60 months. The average age of animals identified with disease in the European Union is higher than this-the average was 86 months in 2001 and has increased since then. This evidence indicates that considering certain tissues in bovines 30 months of age or older to be SRMs, and removing and disposing of those tissues, would eliminate the majority of infectivity present, and removing and disposing of these same tissues from bovines between 12 and 30 months of age would not provide any significant additional protection.

This same point is illustrated in various models. Comer and Huntly (2003) modeled the potential human exposure available in the United Kingdom from 1980 through 2002. They concluded that an estimated total of 54 million bovine oral ID

50

units could have been consumed in that timeframe. This period included both the beginning of the epidemic in cattle, before the disease was recognized and public health control measures were established, and later in the epidemic when control measures were developed and instituted. Comer and Huntly also concluded that 99.4 percent of this estimated exposure was from animals older than 30 months of age. Therefore, SRM restrictions from animals greater than 30 months would reduce the vast majority of potential exposure.

Also, as discussed above in this document, in 2006, FSIS/Harvard incorporated changes based on public comment on an October 2005 simulation that used a modified version of the 2001 Harvard BSE risk assessment model. This was made available to the public, along with the responses to the public comments, as “Harvard Risk Assessment of BSE Update; Phase IA; Supplemental Simulation Results, December 26, 2006.” The base case simulated 500 infected animals introduced, with 50,000 simulation runs of 20-year timeframes. The base case results, which assumed no removal of SRMs, indicated a mean of 700 total infected animals over the 20 years (500 imports and 200 domestic), with a mean of 6,600 cattle oral ID

50

s potentially available for human consumption. In comparison, modeling a requirement for removal from the human food supply of SRMs from cattle 30 months of age or older, assuming 100 percent compliance, indicated a mean of 20 oral ID

50

s potentially available for human consumption over the 20-year time period. The update also modeled requirements for removal from the human food supply of SRMs from cattle 12 months of age and older and 24 months of age and older. There was no significant difference between the results of those models and that which modeled a requirement for removal from the human food supply of SRMs from cattle 30 months of age and older—

viz.,

17 oral ID

50

s each when SRM removal from cattle 12 months of age and older and 24 months of age and older were modeled, compared to 20 oral ID

50

s when removal of SRMs from cattle 30 months of age was modeled.

In summary, we agree with the conclusion that has been widely reached and that has generally been accepted internationally, that the primary public health protective measure regarding BSE is the removal of SRMs from the human food supply, and we concur that the OIE recommendations address those tissues that have been shown to contain BSE infectivity.

Issue:

Several commenters stated that our September 2007 final rule should be withdrawn because the USDA's OIG reported in 2008 that APHIS' import controls are not sufficient to prevent, detect, or address the entry of animals that do not meet import requirements. The commenters expressed concern about APHIS' ability to prevent the introduction of a BSE-infected animal from Canada and concluded that the OIG report demonstrates that APHIS is incapable of adequately enforcing import restrictions necessary to protect the health of U.S. cattle and U.S. consumers.

One commenter stated that the OIG report dealt with, among other things, APHIS' enforcement of requirements in its January 2005 final rule during the period between August 2006 and July 2007. The commenter stated that the report concluded that APHIS' import procedures were not sufficient to prevent unauthorized shipments of live animals into the United States. The commenter stated, further, that according to the OIG report, the

problems that the OIG found regarding compliance with APHIS' January 2005 final rule raise concerns with APHIS' controls over live animal imports and whether the controls are adequate to ensure compliance with import restrictions contained in APHIS' September 2007 final rule. The commenter stated that the OIG audit also referenced other findings regarding APHIS enforcement of its regulations.

The commenter stated that the OIG report contradicts APHIS' statement in its September 2007 final rule that there were only individual instances of errors or violations regarding the provisions of APHIS' January 2005 final rule. The commenter stated that OIG found the errors and violations to be pervasive and stated that the OIG report concluded that problems associated with inaccurate health, age, identification, and pregnancy status on Canadian cattle certificates that were used to import more than 7,000 cattle were not isolated occurrences because they involved at least 52 different Canadian veterinarians and 40 CFIA officials. The commenter stated that APHIS was aware, while preparing its September 2007 final rule, that OIG was auditing its import controls and finding what the commenter termed serious violations of APHIS' enforcement of the January 2005 final rule.

Response:

We agree that the OIG audit referenced by the commenter identified several areas where APHIS could improve its management controls and documentation regarding import procedures. Our response to the audit agrees with many of the recommendations and identifies actions to address them. In many instances, these actions will assist APHIS in documenting issues to provide sufficient information for an analysis to determine the true significance of the reported issues. The report itself acknowledges that OIG had “difficulty assessing the significance of import noncompliance * * *.” (Audit Report, USDA's Controls Over the Importation and Movement of Live Animals, Department of Agriculture, Office of Inspector General, Midwest Region, Report No. 50601-0012-Ch, March 2008). The commenter stated that OIG found errors in certificates to be pervasive, yet the report does not reach this conclusion. OIG identified a total of 211 cattle that were imported with inaccuracies on the health certificate—86 animals inaccurately certified for pregnancy status, 105 animals allegedly inaccurately certified for age, and 21 with inaccurate identification. These inaccuracies are out of a total of 1.1 million animals imported in that year. While we agree with the recommendations in the report and are taking actions to improve our processes, we disagree with the commenter's conclusion that this level of inaccuracies is pervasive and that this demonstrates that APHIS is incapable of enforcing its import regulations.

Issue:

One commenter stated that, in its September 2007 final rule, APHIS relied on disproven findings to support its decision to remove the delay of applicability of those provisions of its January 2005 final rule governing the importation of meat and meat byproducts from BSE minimal-risk regions. The commenter stated that, as justification for its decision to lift the ban on the importation of such commodities from Canada, APHIS asserted that its 2005 evaluation of the epidemiology of BSE cases identified at that time suggested that Canada's BSE outbreak was only a local exposure, based on the relatively small geographical location, temporal association, and the clustering of cases. The commenter stated that this conclusion has been disproven by subsequent outbreaks of BSE that occurred prior to APHIS' publication of its September 2007 final rule.

Response:

The commenter is incorrect that, in its September 2007 final rule, APHIS cited the results of the 2005 evaluation of the epidemiology of BSE cases identified in Canada as justification for lifting the delay of applicability of certain provisions of its January 2005 final rule. In its September 2007 final rule, APHIS explained its rationale for the lifting of the delay of applicability as follows:

Since the date of the partial delay of applicability of our January 2005 final rule, we have obtained additional information regarding all aspects of the issues that prompted the delay of applicability and have conducted additional analyses in line with the plan as described. The risk assessment for this final rule demonstrates the negligible BSE risk from the importation of additional classes of live cattle, including those 30 months of age or older. This includes acknowledging the potential risk pathway that could be available if the SRMs from infected imported cattle entered the ruminant feed supply in contravention of current feed regulations. The negligible risk from the importation of live older cattle therefore gives further support to the conclusion of the risk analysis conducted for our January 2005 final rule regarding meat and meat products derived from bovines of any age in BSE minimal-risk regions. Specifically, the risk is even lower for the importation of meat and meat products, as the SRMs will be removed in accordance with the regulations, than for live bovines. (72 FR 53316)

APHIS' description of the 2005 epidemiological investigation referred to by the commenter appeared in its September 2008 request for comments on the removal of the delay of applicability, and was included, for the sake of completeness, in a chronological list of events that occurred since APHIS' November 2003 proposal to establish the category of BSE minimal-risk regions. In the September 2008 request for comments, APHIS did not point to the 2005 epidemiological investigation as the rationale for removing the delay of applicability.

Issue:

One commenter stated that, in its September 2007 final rule, APHIS projected that 75,000 cull cattle 30 months of age and older would be imported from Canada. However, stated the commenter, USDA data showed that by November 8, 2008, the United States had imported approximately 167,224 cull cattle 30 months of age or older from Canada. The commenter stated that APHIS has explained that projected imports are a key component of the likelihood of BSE infectivity. Thus, stated the commenter, APHIS' estimate that the implementation of the September 2007 final rule could lead to the introduction of between 19 and 105 BSE-infected cattle into the United States—which could, in turn, produce BSE infections in 2 to 75 U.S.-born cattle, lasting over a 20-year period—understates the actual level of BSE infectivity that has likely entered the United States in 2008.

Response:

The commenter is correct that, in analyzing the potential economic effects of its September 2007 final rule, APHIS projected that 75,000 cull cattle 30 months of age and older would be imported into the United States from Canada in 2008. That number was a decrease from the 657,000 head that APHIS had originally projected in its January 2007 proposed rule, and took into account information supplied by commenters on the proposed rule. However, the risk analysis for the September 2007 final rule continued to use a projected importation of 657,000 head. Therefore, the number of cull cattle actually imported under the provisions of the final rule was less than that assumed in the risk analysis.

Issue:

One commenter stated that APHIS' promulgation of its September 2007 final rule violates the Agency's Congressional mandate to take the action necessary to prevent the introduction into or dissemination within the United States and to take the steps necessary to detect, control, and eradicate animal disease. The commenter stated that APHIS acknowledged that the September 2007 final rule could result in the importation

of some BSE-infected cattle from Canada. For this reason, stated the commenter, APHIS should withdraw its September 2007 final rule.

Response:

We disagree that the Secretary acted outside his broad authority under the Animal Health Protection Act (AHPA) (7 U.S.C. 8301

et seq.

) in promulgating the September 2007 final rule. The applicable section of the AHPA provides that “the Secretary may prohibit or restrict * * * the importation or entry of any animal, article, or means of conveyance * * * if the Secretary determines that the prohibition or restriction is necessary to prevent the introduction into or dissemination within the United States of any pest or disease of livestock” (7 U.S.C. 8303 (a)(1)). The United States Court of Appeals for the Ninth Circuit held that this section confers “wide discretion” on the Secretary in dealing with imports and “does not impose any requirement on USDA that all of its actions carry no associated increased risk of disease” (R

-CALF

v.

USDA,

415 F.3d 1078, 1094). The court found that open borders are a default under the AHPA and that the Secretary can close them only when he has determined that it is necessary. The court noted that the statute's use of the word “may” suggests that the Secretary has broad discretion to decide whether to close the borders at all (

id.

at 1094-1095). We do not believe that the September 2007 final rule violates our statutory mandate and we deny the commenter's request to withdraw the rule on this basis.

Issue:

One commenter stated that the United States should prohibit the importation of beef or cattle from any country known to have BSE. Another commenter stated that beef and cattle trade with Canada should not be expanded until, among other actions pertaining just to live animals, Canada can verify 100 percent compliance with its ruminant feed ban and that its cattle herd and beef products are BSE-free.

Response:

The actions recommended by the commenter are not supported by scientific evidence or empirical data, nor are they consistent with internationally accepted animal health standards. Such action, if taken in turn by U.S. trading partners with regard to U.S. beef and cattle, would eliminate the export of beef and cattle from the United States.

In a series of documents published from November 2003 through September 2008, which we discuss above in this document, APHIS provides the scientific rationale for classifying Canada as a BSE minimal-risk region and allowing the importation of certain ruminants and ruminant products from Canada under specified conditions.

The regulatory conditions for the importation into the United States of beef and cattle from a BSE minimal-risk region such as Canada are consistent with the OIE Code for trade in beef and live animals from a country recognized by the OIE as having controlled risk for BSE. Both Canada and the United States are recognized as BSE controlled risk countries.

The OIE, of which the United States is a Member country, is the internationally recognized standard-setting body that develops science-based recommendations for the safe trade of animals and animal products. The World Trade Organization has recognized the OIE as the international forum for setting animal health standards, reporting global animal disease events, and presenting guidelines and recommendations on sanitary measures relating to animal health.

The OIE facilitates intergovernmental cooperation to prevent the spread of contagious diseases in animals by sharing scientific research among its members. The major functions of the OIE are to collect and disseminate information on the distribution and occurrence of animal diseases and to ensure that science-based standards govern international trade in animals and animal products. The OIE carries out its function through the development and revision of international standards for diagnostic tests, vaccines, and the safe international trade of animals and animal products.

The OIE develops risk-based standards, which, if agreed upon by Member countries through consensus, are published in the OIE Terrestrial Animal Health Code (Code). However, each OIE Member country is obligated to review and comment on proposed OIE standards, and make decisions regarding the adoption of those standards, strictly on their scientific merits.

As an OIE Member country, the United States reviews and, where appropriate, comments on all draft OIE chapters and revisions. As part of the U.S. consideration of OIE drafts, APHIS distributes these drafts to the U.S. livestock and aquaculture industries, veterinary experts in various U.S. academic institutions, and other interested persons for review and comment.

In addition, each year, prior to formulating its comments for the OIE annual meeting, APHIS makes available on its Web site those potential changes to the Code that the OIE has submitted to Member countries for comment, and accepts information and recommendations from the public regarding those proposed changes. Through its OIE Reference Laboratories and Collaborating Centers, APHIS also provides OIE Member countries with technical assistance and expert advice on disease surveillance and control and risk analysis, as well as diagnostic assistance, evaluation, and consultation.

Over the years, the OIE Member countries, including the United States, have agreed by consensus to amend the OIE Code based on increased scientific evidence regarding the disease. The OIE Code reflects the current understanding that, depending on multiple factors, there can be gradations in the risk of the BSE agent being moved from one country to another, and gradations in the risk of BSE transmission and amplification within any particular country. As a member of the OIE, the United States, represented by APHIS, has been actively involved in the development of the OIE Code and fully supports the OIE position that gradations in BSE risk among regions should be recognized and that trade should be commensurate with risk.

Issue:

One commenter stated that beef and cattle trade with Canada should not be expanded until U.S. international beef export markets are firmly established. The commenter also urged that, if the restrictions on importations from Canada are removed, American cattle producers be compensated for economic disadvantages that might arise from such importations. Another commenter stated that U.S. exports are suffering because the United States requirements for imports from Canada are consistent with OIE standards but less stringent than the requirements imposed by other countries for the importation into those countries of beef from the United States.

Another commenter stated that, as noted above, in its September 2007 final rule, APHIS projected that 75,000 cull cattle 30 months of age older would be imported from Canada. However, stated the commenter, USDA data showed that by November 8, 2008, the United States had imported approximately 167,224 cull cattle 30 months of age or older from Canada. The commenter stated that although APHIS had projected revenue losses of over $66 million for U.S. cattle producers due to the importation from Canada of cattle 30 months of age or older, the larger number of such cattle actually imported will make those losses significantly higher.

Response:

As we stated in our September 2007 final rule, APHIS does

not have the statutory authority to restrict trade based purely on its potential economic impact, market access effects, or quantity of products expected to be imported. Under the AHPA, the Secretary of Agriculture may prohibit or restrict the importation or entry of any animal or article when the Secretary determines it is necessary to prevent the introduction or dissemination of a pest or disease of livestock. This authority has been delegated to APHIS.

We note that neither our January 2005 final rule nor our September 2007 final rule made any commodities eligible for importation from Canada that were not already allowed importation prior to May 2003, when a BSE-infected cow was diagnosed in Canada. One difference between the current situation and pre-May 2003, however, is that certain of the commodities that are now eligible for importation are subject to risk-mitigating importation conditions appropriate to the fact that BSE has been detected in Canada and that we consider that country a minimal-risk region for BSE. Both Canada and the United Sta

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