The RA was conducted by APHIS's Veterinary Services (VS).  After banning Canadian ruminants and ruminant products in 5/03, the USDA wanted to loosen the ban.  The risk assessment was intended to provide the rationale.  Such a RA is recommended by the OIE.  This is importantant since the OIE recommendations are recognized by the WTO (page 14 of RA PDF file).- i.e. loosening of the rules could permit or encourage other countries to ban US beef.  The economic loss associated with that was evaluated in a Commerce Dept. analysis.

In advance of even this risk assessment much less the actual loosened rule it was intented to support, the USDA announced on 8/8/03 that it would began accepting applications to permit importing some Canadian beef products- including beef from cows less that 30 months old.  The proposed rule loosening this RA supports was announced on 10/31/03.

...Despite the single case of BSE, VS considers Canada as a country that presents a minimal
BSE risk for import purposes. The risk assessment provides the rationale for that
conclusion, based both on OIE criteria for a minimal risk BSE region and on factors that
VS has defined that it will use to address OIE recommendations for a minimal risk
region. VS and OIE address the same issues.

The analysis describes the epidemiological characteristics of BSE that are relevant to the
risk of imported ruminants and ruminant products from Canada and describes mitigations
appropriate to that risk. The commodities discussed in this analysis were relatively freely
traded prior to the ban and include feeder cattle and cattle for immediate slaughter less
than 30 months of age, cervids and non-cervine ruminants for immediate slaughter, and
meat and other products. The mitigations under consideration included a ban on the
feeding of material of ruminant origin to ruminants, age restrictions on imported or
source animals to an age at which infectious levels of the agent would be unlikely, feed
source control, various processing and movement controls, and Canadian Food Inspection
Agency (CFIA) verification that the mitigations were applied appropriately.

VS concluded that the surveillance, prevention, and control measures implemented by
Canada are sufficient to minimize the risk of importing BSE into the United States,
provided that additional mitigation measures are implemented as described. Furthermore,
VS concludes that the mitigations that VS proposes are sufficient to allow resumption of
trade in these animals and animal products.

On May 29, 2003, USDA published an interim rule adding Canada to the list of countries
that are considered to be affected with BSE (APHIS 2003a). On August 26, 2003, based
on a thorough scientific analysis, USDA began issuing import permits for certain
ruminant derived products from Canada (APHIS 2003b).  This analysis is being
conducted to determine if, and under what conditions, trade in designated ruminants and
ruminant products may be resumed without the need for an import permit. This analysis
describes the risk factors associated with those animals and animal products as well as the
applicable mitigations.

Because of the limited scope of its regulatory authority, this APHIS analysis will not
focus on human health issues, with one exception. Human health issues will be
addressed solely in the context of potential exposure of and consequences to humans
should BSE-infected material enter the United States AND enter the human food supply.
Relevant to this, an evaluation conducted in the context of both human and animal health
by the Harvard Center for Risk Analysis (Harvard Center for Risk Analysis et al., 2001)
concluded that the United States is highly resistant to spread and establishment of BSE in
the unlikely event of its entry into the United States.

...Therefore, although it has not been confirmed, the
most likely explanation is that the one case resulted from exposure to contaminated feed.
The infected animal was born prior to the implementation of a feed ban within Canada
and could have been fed contaminated feed at an early age. It is unlikely that a definitive
source will ever be firmly established.

The OIE categorizes countries with indigenous cases of BSE as minimal, moderate, or
high risk for BSE, based on established criteria (OIE 2002a). The primary differentiating
standard for these designations is the incidence rate of indigenous cases. For a minimal
risk country, the incidence rate must have been less than one case per million during each
of the last four consecutive 12 month periods within the cattle population over 24 months
of age. Canada’s adult cattle population is approximately 5.5 million animals, and only
one animal was confirmed with BSE in the last 12 month period. Over the entire
preceding three consecutive years, the incidence rate was 0 (zero). This incidence rate is
within the parameters for a minimal risk country, and well below the parameters for a
moderate risk country.

Additional factors relevant to the OIE risk classification include an implementation of an
effective ruminant-to-ruminant feed ban, awareness and education programs, compulsory
notification of suspect BSE cases, surveillance and monitoring program, an appropriately
conducted risk assessment (CFIA 2002), a competent diagnostic capacity, and an
appropriate slaughter/culling program to address risk animals when a positive case is
identified. Canada fully meets or exceeds all of these factors, with the exception of
duration of the feed ban.

.......Since 1997, Canada has maintained a mammalian to ruminant feed
ban, with requirements similar to the feed ban in place in the United States (DHHS).
The single OIE criterion that Canada did not meet at the time this analysis was conducted
was duration of the feed ban. The current OIE recommendation (OIE 2002a) is that a
minimal risk country should have had an effective feed ban in place for eight years. The
current feed ban in Canada has been in place for six years. A strict reading would,
therefore, classify Canada as a moderate risk country because the current feed ban has
been in place for six years.  (ed:  per page 14 of the RA PDF file- Canada started the feed ban
in '97- the same year as the US)

VS considers the six year length of the feed ban in Canada as sufficient to classify
Canada as a minimal risk region for BSE. The OIE recommendation of eight years may
be set at a conservative level to account for the wide range that has been reported for the
incubation period of BSE. Because of the variability of current estimates associated with
the incubation period for BSE, VS chose not to specify an amount of time that a feed ban
should be in place for a minimal risk country. Rather, VS considered the sum total of the
control mechanisms (e.g., effectiveness of surveillance, import controls, and feed ban) in
place at the time of the diagnosis and the actions taken after it (e.g., epidemiological
investigations, depopulation), thereby allowing the actions CFIA took in other elements
to compensate for a shorter feed ban. As an example relevant to this point and discussed
in more detail elsewhere in this document, the level of surveillance conducted in Canada
exceeded the OIE recommendations. In addition, Canada’s surveillance was both active
and targeted in such a manner as to exceed the OIE recommendations. VS considers
Canada to exhibit minimal risk for BSE even though the feed ban has not been in place
for eight years because Canada has compensated in the areas of surveillance and control.

VS considers OIE recognition of status in developing trade policies. However, VS is
aware that OIE recommendations are evolving. In fact, VS has proposed revisions of the
OIE recommendations for BSE and has made comments to reflect this through official
channels. VS is concerned that some OIE criteria may be too general and others too
specific. At one end of the spectrum, the OIE criterion stating that “a risk
assessment…has been conducted and it has been demonstrated that appropriate measures
have been taken for the relevant period of time to manage any risk identified” (OIE
2002a) appears to be extremely general. On the other end of the spectrum, as discussed
previously, the requirement that “the ban on feeding ruminants with meat and bone meal
and greaves derived from ruminants has been effectively enforced for at least 8 years”
may be too restrictive when other factors are considered.

VS definition of BSE minimal risk region  (snippets)

Re: the feed ban:
(c) The region has 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
in place, and compliance with the ban appears to be good.
This factor distinguishes between regions with effective feed bans and those
without them. If an animal with BSE were born after a feed ban was
implemented, the observation suggests that the feed ban may not have been
effectively enforced.

.....Under the ban in place in Canada, mammalian protein
may not be fed to ruminants with certain exceptions. These exceptions include pure
porcine or equine protein, blood, milk, and gelatin. The feed ban is essentially the same
as the feed ban in place in the United States (DHHS)......

Canadian government authorities inspect rendering facilities, feed manufacturers and feed
retailers to ensure compliance with the feed ban (CFIA 2003a). Rendering facilities are
regulated under an annual permit system, and compliance with the regulations is verified
through at least one inspection each year. Feed manufacturers or mills, feed retailers, and
farms have been inspected on a routine basis. These inspections have revealed that the
level of compliance is good, and there is no evidence of significant noncompliance with
the feed ban (CFIA 2003a).
 

The investigation included a consideration of several possibilities for the source of
exposure to the infected cow (CFIA 2003). Although it has not been confirmed, CFIA
assumed, based on the age of the cow, that the animal was exposed through contaminated
feed. The infected animal was born prior to implantation of the feed ban in Canada and
could have been exposed to contaminated feed at an early age (CFIA 2003a).....
......Although the possibility exists that the original
source of the BSE agent could have been imported, there was no evidence that this
resulted from an illegal import. The BSE agent could have originated from animals
imported from the UK prior to implementation of import restrictions in 1990.

.....More than 2,700 head of cattle were culled. As
part of the culling activity, more than 2,000 animals that were 24 months of age or older
were tested. The 700 that were not tested were less than 24 months of age. No further
evidence of BSE was detected in any of these animals.

In addition, Canada prohibited the use of certain tissues, which have been called specified
risk materials, in the human food supply (CFIA 2003). These are tissues in which the
infectious agent has been shown experimentally to localize.

....Since compliance with the feed ban appears to have been good (CFIA
2003a), it is unlikely that the animal recently confirmed with BSE ingested contaminated
feed during the period covered by the ban. This suggests that the ban has been effective.
All of these actions will further reduce the already minimal risk of the spread of BSE.

.....Furthermore, it cannot be assumed that there is complete
compliance with a feed ban, which is the most effective mitigation for contaminated feed.
Therefore, VS considered it necessary to mitigate risk arising from alternative pathways
or lack of compliance with a feed ban.....

The primary source of BSE infection is commercial feed contaminated with the infectious
agent. Scientific evidence (Wilesmith, et al. 1988; 1991; 1992) shows that feed
contamination results from the incorporation of ingredients that contain ruminant protein
derived from infected animals. Standard rendering processes do not completely
inactivate the BSE agent.  Therefore, rendered protein such as meat-and-bone meal
derived from infected animals may contain the infectious agent. Bans prohibiting
incorporation of mammalian or ruminant protein into ruminant feed are imposed to
mitigate risk.

Levels of infectious agent in certain tissues vary with the age of animal, so age of the
animal influences risk. Pathogenesis studies, where tissues obtained from orally infected
calves were assayed for infectivity, have shown that infectivity was not detected in most
tissues until at least 32 months post-exposure (Wells, et al. 1998; Wells, et al. 1994; EU
SSC 2002). The exception to this is the distal ileum, the distal portion of the small
intestine, where infectivity was confirmed from experimentally infected animals as early
as 6 months post-exposure.
Similar observations were made in sheep and goats (EU SSC 2002). In these animals,
infectivity could not be demonstrated in the tissues until at least 16 months post-exposure
to the agent.

Research demonstrates that the incubation period for BSE is apparently linked to the
infectious dose received, i.e., the larger an infectious dose received, the shorter the
incubation period (EU SSC 2002).....This research also suggests that a calf
must receive an oral dose of 100 grams of infected brain material containing high levels
of the infectious agent to produce disease within a minimum of approximately 30 months
(EU SSC 2002; DEFRA 2003; EC 2002, 2003).

BSE testing in the European Union (EU) was conducted throughout the year 2001. This
testing revealed only two positive animals that were younger than 30 months of age in a
total of 2,147 positive cases. Of note is that these animals were 28 and 29 months of age.
For reference, in 2001, a total of 8,516,227 tests were conducted within the EU, and, of
those, 1,366,243 tests were conducted on animals less than 30 months of age. In 2002,
there were no animals less than 30 months of age that were positive in the EU testing
scheme. Approximately 10.2 million tests were conducted in EU Member States in 2002,
and, of these, 1.6 million were conducted on animals less than 30 months of age. The
average mean age of positive animals in the EU in 2002 was 96.9 months, an increase
from 85.9 months in 2001 (EC 2002, 2003).

......Infected cattle younger than 30 months of age or sheep and
goats less than 16 months of age are unlikely to have infectious levels of the prion protein
(EU SSC 2002; Wells, et al. 1994; Wells, et al. 1998). The 30 month age limit is
accepted internationally in BSE standards set by various countries and is consistent with
OIE recommendations (OIE 2002a).

In "tissue localization":

...Affiliated  tissues or structures such as skull or vertebral column are considered risk materials
because of the difficulty in separating out small tissues such as dorsal root ganglia from
the vertebral column.  Possibilities for cross contamination from risk materials must also be considered. For
example, tonsils are directly and tightly attached to tongues, so removal of tonsil from
tongues should mitigate risk.  However, even cattle carrying the infectious agent are unlikely to carry that agent
in tissues that have not had demonstrated infectivity (e.g., muscle, liver, skin, hide, milk,
embryos) or products derived from these tissues (Wells, et al. 1994; Wells, et al. 1998;
Wrathall, et al. 2002)......
Of note in this regard is that while muscle (meat) from cattle is not, by itself, a risk tissue,
it can be contaminated with vertebral column or spinal cord, and intestines from cattle
younger than 30 months of age (i.e., as early as six months of age) may have infectious
levels of the agent. Therefore, removal of intestine in order to remove the distal ileum
from cattle less than 30 months of age is justified to mitigate risk.

In "Source species":

.....However, results
from experimental infections of sheep have shown that the BSE prion is distributed more

widely in sheep tissues than in cattle (Foster, et al. 1996; Foster, et al. 2001).T  his
distribution is similar to the distribution of scrapie infections in sheep. In scrapie, the
agent may be found in the lymphoreticular system and in peripheral nerves (Foster, et al.
1996; Foster, et al. 2001). It is assumed, based on analogy with scrapie, that, if it infected
sheep naturally, BSE would distribute similarly.

There may be risks associated with contamination through processing. For example,
certain tissues derived from animals killed by air injection stunning or processed using
mechanically separated meat recovery systems may contain emboli or fragments from
high risk tissues like brain and spinal cord, posing risk by contamination (Garland,
Bauer, and Bailey 1996; Grandin 1997; Anil, et al. 1999).

Risk deliberations were undertaken by a permanent technical advisory team of experts
within APHIS, the TSE Working Group. This group is composed of 13 members, one or
two from each of the following APHIS units: Centers for Epidemiology and Animal
Health, National Veterinary Services Laboratories, National Center for Animal Health
Programs, VS Regional Offices, Center for Veterinary Biologics, National Center for
Import and Export, Plant Protection and Quarantine, and Legislative and Public Affairs.
The group was formed several years ago to address and make policy recommendations
regarding issues associated with TSEs.

Animals can be mitigated by limiting imports to animals that have not been fed
ruminant proteins (other than milk protein) or, where there is not a maximum age at
which the animals might be slaughtered, that were born after the feed ban or
removing risk materials;
<snip>
Tissues of animals of any species can be mitigated by requiring that risk materials
(e.g., intestine in bovids) are removed, either in the United States under FSIS
supervision, or in Canada with CFIA certification.  Because of evidence the
infectious levels of the BSE agent may be present in the distal ileum of infected
bovids as early as 6 months post-exposure, removal of intestines in a manner
considered adequate to ensure that the materials are not fed to ruminants should
further mitigate risk of cattle less than 30 months of age.

Tables 1 and 2 (for live animals and products) give Commodities,   Required Risk Mitigations  and  Risk factor/mitigation Summary
Three examples:

Bovids imported for slaughter by 30 months of age, including veal calves (intended for immediate slaughter)

Trucks are sealed and contents documented to move direct to slaughter as a group; CFIA verifies that the animals were under 30 months of age and not known to have been fed ruminant proteins during their lifetime; intestine is removed at U.S. plant under FSIS supervision and disposed of appropriately; animals enter United States through VS designated ports of entry.

Source is young animals not known to have been fed ruminant proteins; CFIA and FSIS verify; risk materials are removed; movement is controlled.

Bovids imported for feeding in a U.S. feedlot prior to slaughter by 30 months of age or less.

CFIA verifies that the animals are less than 30 months of age and are not known to have been fed ruminant protein  during their lifetime; animals must be moved to designated feedlot as a group and slaughter at less than 30 months of age; intestine is removed at U.S. plant under FSIS supervision and disposed of appropriately; cattle come in through VS designated ports of entry; ear tattoo identifies them as Canadian in origin.

Source is young animals not known to have been fed ruminant proteins; feedlot is designated; movement to feedlot is controlled; CFIA and FSIS verify; risk materials are removed; animals are identified as Canadian.

Bovine meat, fresh, chilled, or frozen (including veal), from animals less than 30 months of age that meets USDA definition of meat.

CFIA verifies that the animals were less than 30 months of age when slaughtered and are not known to have been fed ruminant proteins during their lifetime; slaughter plant only kills bovids less than 30 months of age or complies with a facility segregation procedure approved by CFIA and endorsed by APHIS for bovids older than 30 months of age; intestine is removed; meat processing must meet USDA standards.

Source is young animals not fed ruminant proteins; slaughter plant is segregated or dedicated to prevent commingling or diversion; intestine is removed, CFIA verifies.

Cervine offal (viscera or non-muscle tissues removed from a carcass at slaughter), fresh, chilled or frozen

CFIA verifies that the animals were born after the feed ban and are not known to have been fed ruminant proteins during their lifetime; animals must be members of a herd not known to be infected with or exposed to a TSE.

Source is animals born after feed ban and not known to have been fed ruminant proteins; herd is not known to be infected with TSE; CFIA verifies.Would the above allow AMR meat?

<snip>

In summary, VS considers that Canada is a minimal risk region for BSE.
However, in light of the recent positive animal, VS has analyzed BSE mitigations
relevant to live animals and products that might be imported from Canada. These
additional mitigation measures address epidemiological risk factors for disease
transmission that VS has identified. VS concludes from this analysis that the
requirements described in this analysis are adequate to mitigate BSE risk from Canadian
imports of these products.

Based on these conclusions, and in compliance with OIE recommendations (OIE 2002b),
adequate information was presented for VS to complete the risk assessment at this point.
However, in the interests of thoroughness, VS continued its assessment to briefly address
risk associated with exposure and consequence.

Exposure Assessment

VS considers it unlikely that infectious levels of BSE would be introduced into the U.S.
from a minimal risk country like Canada with any of the commodities discussed in this
assessment. Also, VS considers that, even if the BSE agent were introduced into the
United States, it would be extremely unlikely to be introduced into commercial animal
feed and thereby infect animals. That is a primary result of the nature of the products,
none of which is likely to become a significant animal feed component.

.....These conclusions are consistent with the results of the Harvard study (Harvard Center
for Risk Analysis et al. 2001). The analysts developed a probabilistic simulation model
to characterize the consequences of introducing BSE into the United States. The model
analyzed the effects of introducing hypothetical numbers of infected animals the United
States. The model allowed predictions of the number of newly infected animals that
would result from introduction of BSE, the time course of the disease following its
introduction, and the potential for human exposure.
For example, in a hypothetical scenario in which ten BSE-infected cattle were imported
into the United States, the results suggested that an average of only three new cases of
BSE would occur. These cases would occur primarily as a result of non-compliance with
the feed ban. In the unlikely event that disease was introduced, it would be almost certain
to be eliminated within 20 years under the conditions currently existing in the United
States.
Reducing the hypothetical number of infected animals imported to one resulted in an
estimate of less than one new BSE case in 20 years
.<snip>
The study concluded that the most effective U.S. measure preventing BSE spread is the
feed ban instituted by the Food and Drug Administration (FDA) in 1997 (DHHS) to
prevent recycling of potentially infectious cattle tissues. The FDA feed ban greatly
reduces the chance that BSE will spread from a sick animal to other cattle through feed.

Consequence Assessment:
<direct and indirect consequences are addressed>...Direct consequences include
animal infection, disease and production losses, and public health consequences. Indirect
consequences include surveillance and control costs, compensation costs, potential trade
losses, and adverse consequences to the environment.
Animal health
....If any infected animals did enter, the disease would be unlikely to spread to
others and, essentially the infected animals should constitute dead end hosts.
Public health
.....Although there are many unknown factors relative
to development of vCJD, including the definition of an infectious dose or the length of an
incubation period, of significance to this analysis is that the available information
compiled from a variety of studies suggests the infectious agent may be 10 to 100,000
times less pathogenic in humans than in cattle (summarized in Harvard Center for Risk
Analysis 2001; EUSSC 2000).

.....The Harvard study found that
even if BSE were to enter the United States, it would be unlikely to spread. Therefore, it
would be unlikely to enter the human food chain. Third, is the extremely low likelihood
that, should an infected carcass enter the food chain, the tissues that present the highest
risk of infection would be available for human consumption. The Harvard study
demonstrated that, even if BSE were to occur in the United States, little infectivity would
be available for potential human exposure.

Surveillance, control, and indemnity
An Interagency Working Group formed by the Secretary of Agriculture issued a report on
risks and economic impacts associated with the potential introduction of BSE into the
United States (USDA 2002). In addition to the other costs, a BSE occurrence in the
United States would cause economic costs due directly to costs of the government
response to the disease. This would include both direct losses to BSE and depopulation
of contact herds. A single case would be likely to necessitate the depopulation of several
thousand animals along with associated indemnity costs.

....Specifically, as of August 31, 2003,
CFIA documented expenditures related to animal infection, disease, production losses,
and surveillance and control costs of approximately $5.7 million (Canadian dollars) on
salaries, $1.4 million on costs other than salaries, and $7.0 million on indemnities. The
total estimated costs of BSE detection and the CFIA response in Canada were $14 million
Canadian dollars, which is equivalent to approximately $19 million U.S. dollars. For
reference, there are approximately 45 million adult cattle in the United States (USDA-NASS)
in comparison to approximately 5.5 million in Canada (CFIA 2003a).

Effects on trade
Trade-related economic consequences of a BSE introduction from Canada would result if
other countries refused to accept U.S. ruminant products. Again, the Canadian
experience provides relevant information on trade consequences. In this regard, the
United States could expect the spectrum of trading partners imposing restrictions on the
U.S. because of BSE to be similar to the countries imposing restrictions on Canada. As
of August 11, 2003, 49 countries had imposed restrictions on Canadian animals and
products as a result of the BSE-infected animal.

Countries imposing restrictions on Canada included Japan, Mexico, and Korea (CFIA
2003). These three countries also constitute major U.S. export markets. The value of lost
exports to these three U.S. ruminant markets alone would total $3 billion annually if trade
restrictions were enforced against the United States: Japan ($1.2 billion); Mexico ($1.12
billion); and South Korea ($712 million). Indirect economic losses to U.S. firms that
support ruminant exports to these three markets would equal an additional $2.5 billion
annually. The magnitude of these values reflects both animal and product exports (Green
and Grannis 2003).

More than 33 thousand full-time U.S. jobs, accounting for almost $1 billion in wages
annually, could be jeopardized by loss of these three markets. In the longer term, if trade
restrictions persisted and alternative export markets did not develop, the U.S. ruminant
production sector could contract, allowing other supplying countries to establish trade
relationships in the absence of U.S. supply (Green and Grannis 2003).

Risk Estimation
VS concludes from this assessment that the surveillance, prevention, and control
measures implemented by Canada are sufficient to minimize the risk of importing BSE
into the United States, provided that additional mitigation measures are implemented as
described. Furthermore, VS concludes that the animals and animal products under
consideration in this analysis are of low or minimal risk in view of the certification
requirements that will be implemented.

These conclusions are consistent with the 2001 Harvard study, which found that the
measures taken by the U.S. government and industry make the United States robust
against the spread of BSE, should it be introduced into the country. Of particular
significance in this regard is the feed ban instituted by the FDA in 1997 to prevent the
recycling of potentially infectious ruminant tissues (DHHS).

In summary, VS considers the risk of BSE-imported animals or animal products entering
the United States from Canada and exposing U.S. livestock through feeding of infected
materials to susceptible animals, to be low.

(Animal and Plant Health Inspection Service (APHIS), January 1, 2003e. Restrictions on
importation of meat and edible products from ruminants due to bovine spongiform
Encephalopathy, Title 9, Code of Federal Regulations, Part 94.18.

Harvard Center for Risk Analysis, et al., November 26, 2001; Evaluation of the Potential
for Bovine Spongiform Encephalopathy in the United States, copy available at
http://www.aphis.usda.gov/lpa/issues/bse/bse-riskassmt.html.

United States Department of Agriculture (USDA), February 6, 2002. Animal Disease
Risk Assessment, Prevention, and Control act of 2001 (PL 107-9), Final report prepared
by the PL 107-9 Interagency Working Group, Appendix 6.

United States Department of Agriculture (USDA), National Agricultural Statistics
Service (NASS), January 1, 2003, Reports by Commodity; Cattle; Inventory.
www.usda.gov/nass/pubs/estindx.htm.
Definitions:
Mechanically separated meat: Process for separating meat from bone using pressurized
equipment in which bone fragments can contaminate meat.