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From: TSS ()
Subject: Re: Canada investigates possible mad cow case CFIA source confirms
Date: January 23, 2006 at 7:31 am PST

In Reply to: Re: Canada investigates possible mad cow case CFIA source confirms posted by TSS on January 23, 2006 at 7:21 am:

Working Group Report on

the Assessment of the Geographical BSE-Risk (GBR) of

CANADA

2004

snip...

- 2 -

2. EXTERNAL CHALLENGES

2.1 Import of cattle from BSE-Risk2 countries

An overview of the data on live cattle imports is presented in table 1 and is based on

data as provided in the country dossier (CD) and corresponding data on relevant exports

as available from BSE risk countries that exported to Canada. Only data from risk

periods are indicated, i.e. those periods when exports from a BSE risk country already

represented an external challenge, according to the SSC opinion on the GBR (SSC July

2000 and updated January 2002).

• According to the CD, 231 cattle were imported from UK during the years 1980 to

1990 and no cattle imports from UK were recorded after 1990.

• According to Eurostat, altogether 198 cattle have been imported from the UK during

the years 1980 to 1990, Additionally 500 were recorded in 1993; this import is

1 For the purpose of the GBR assessment the abbreviation "MBM" refers to rendering products, in particular

the commodities Meat and Bone Meal as such; Meat Meal; Bone Meal; and Greaves. With regard to imports

it refers to the customs code 230110 "flours, meals and pellets, made from meat or offal, not fit for human

2 BSE-Risk countries are all countries already assessed as GBR III or IV or with at least one confirmed

Annex to the EFSA Scientific Report (2004) 2, 1-14 on the Assessment of the

Geographical BSE Risk of Canada

- 3 -

mentioned in Eurostat and the updated UK export statistic as male calves, but not

mentioned in the original UK export statistics. According to the CD, detailed

investigations were carried out and it is very unlikely that the 500 calves have been

imported. Therefore, they were not taken into account.

• According to the CD, in 1990 all cattle imported from UK and Ireland since 1982

were placed in a monitoring program.

• Following the occurrence of the BSE index case in 1993 (imported from UK in 1987

at the age of 6 months), an attempt was made to trace all other cattle imported from

UK between 1982 and 1990.

• Of the 231 cattle imported from the UK between 1980 and 1990, 108 animals had

been slaughtered and 9 had died. From the remaining, 37 were exported, 76 were

sent to incineration and one was buried; these were not entering the rendering system

and therefore not taken into account.

• According to the CD, 16 cattle were imported from Ireland (according to Eurostat

20), of which 9 were slaughtered, 3 died. The remaining 4 were incinerated and did

therefore not enter the rendering system. According to the CD, the 6 animals which

were imported in 1990 according to Eurostat, were never imported.

• Moreover 22 cattle have been imported from Japan (through USA), of which 4 were

exported (excluded from the table) and 14 were destroyed and therefore not entering

the rendering system, 4 were slaughtered.

• Of 28 imported bovines from Denmark, 1 was destroyed and 1 was exported. Of the

19 buffalos imported in 2000, 1 was incinerated and the others were ordered to be

destroyed.

• Additionally in total 264 cattle according to the CD (276 according to other sources)

were imported from Austria, France, Germany, Hungary, Italy, The Netherlands and

Switzerland.

• The numbers imported according to the CD and Eurostat are very similar. Some

discrepancies in the year of import can be explained by an extended quarantine;

therefore it is likely that imports according to Eurostat in 1980 and imports

according to the CD in 1981 are referring to the same animals.

• Additionally, between 16.000 and 340.000 bovines have annually been imported

from US, almost all are steers and heifers. In total, between 1981 and 2003,

according to the CD more than 2.3 million, according to other sources 1.5 million

cattle have been imported.

• According to the CD, feeder/slaughter cattle represent typically more than 90% of

the imported cattle from the USA; therefore, only 10% of the imported cattle have

been taken into account.

snip...

Annex to the EFSA Scientific Report (2004) 2, 1-15 on the Assessment of the

Geographical BSE Risk of Canada

2.2 Import of MBM or MBM-containing feedstuffs from BSE-Risk

countries

An overview of the data on MBM imports is presented in table 2 and is based on data

provided in the country dossier (CD) and corresponding data on relevant exports as

available from BSE risk countries that exported to Canada. Only data from risk periods

are indicated, i.e. those periods when exports from a BSE risk country already

represented an external challenge, according to the SSC opinion on the GBR (SSC, July

2000 and updated January 2002).

According to the CD, no imports of MBM took place from UK since 1978 (initially

because of FMD regulations).

• According to Eurostat data, Canada imported 149 tons MBM from the UK in the

period of 1993 to 2001. According to up-dated MBM statistics from UK (August

2001) no mammalian MBM was exported to Canada from 1993 – 1996. As it was

illegal to export mammalian meat meal, bone meal and MBM from UK since

27/03/1996, exports indicated after that date should only have included nonmammalian

MBM. Therefore, these imports were not taken into account.

• According to the CD, imports of MBM have taken place from Denmark, Germany,

France, Japan and US.

• According to Eurostat Canada imported MBM from Denmark, Belgium, France and

Ireland.

• According to the CD further investigations concluded that all imported MBM from

Denmark consisted of pork and poultry origin and was directly imported for

aquaculture, the imported MBM from France was feather meal, the imported MBM

from Germany was poultry meal for aquaculture and the imported MBM from

Belgium was haemoglobin; therefore these imports were not taken into account.

• The main imports of MBM were of US origin, according to the CD around 250.000

tons, according to other sources around 310.000 tons between 1988 and 2003.

snip...

2.3 Overall assessment of the external challenge

The level of the external challenge that has to be met by the BSE/cattle system is

estimated according to the guidance given by the SSC in its final opinion on the GBR of

July 2000 (as updated in January 2002).

Live cattle imports:

In total the country imported according to the CD more than 2.3 million, according to

other data 1.5 million live cattle from BSE risk countries, of which 231 (CD)

respectively 698 (other sources) came from the UK. The numbers shown in table 1 are

the raw import figures and are not reflecting the adjusted imports for the assessment of

the external challenge. Broken down to 5 year periods the resulting external challenge is

as given in table 3. This assessment takes into account the different aspects discussed

above that allow to assume that certain imported cattle did not enter the domestic

BSE/cattle system, i.e. were not rendered into feed. In the case of Canada, the 500 cattle

imported from UK according to Eurostat were not taken into account and it is assumed

that all incinerated, buried, exported animals and the animals still alive did not enter the

rendering system and were therefore excluded from the external challenge.

MBM imports:

In total the country imported according to the CD around 300.000 tons, according to

other sources nearly 360.000 tons of MBM from BSE risk countries, of which 149 tons

came from the UK. The majority consisted of MBM imported from the US. The

numbers shown in table 2 are the raw import figures and are not reflecting the adjusted

imports for the assessment of the external challenge. Broken down to 5 year periods the

resulting external challenge is as given in table 3. This assessment takes into account

the different aspects discussed above that allow to assume that certain imported MBM

did not enter the domestic BSE/cattle system or did not represent an external challenge

for other reasons. As it was illegal to export mammalian meat meal, bone meal and

MBM from UK since 27/03/1996, exports indicated after that date should only have

included non-mammalian MBM. In the case of Canada all imported MBM from UK,

Germany, Belgium, Denmark and France was not taken into account.

snip...

3. STABILITY

3.1 Overall appreciation of the ability to avoid recycling of BSE

infectivity, should it enter processing

Feeding

The annual Canadian production of MBM is approximately 575,000 tons of which

approx. 40,000 tons are exported each year, mainly to USA.

Use of MBM in cattle feed

• Before the feed ban, dairy cattle received supplementary feed containing MBM

during their productive life (maximum 200-400 g MBM per day). Beef cattle in the

western part of the country do not usually receive complementary feed. Beef cattle

in the eastern part receive normally no supplement protein but the calves could have

access to creep feeds containing MBM, after weaning the ratios may have contained

supplemental protein containing MBM (100-400 g per day).

• According to the CD, MBM is mainly fed to pigs and poultry and included in pet

food.

• According to the CD, only a proportion of dairy cattle may have received MBM.

Feed bans

• Before 1997, there was no legal restriction to include MBM into cattle feed.

• An MBM-ban was introduced in August 1997; it is forbidden since to feed

mammalian MBM to ruminants except if of pure porcine, equine and non

mammalian origin, i.e. in practice a ruminant-to-ruminant ban (RMBM-ban).

Annex to the EFSA Scientific Report (2004) 2, 1-15 on the Assessment of the

Geographical BSE Risk of Canada

- 9 -

Potential for cross-contamination and measures taken against

• Cross-contamination in the about 600 feed mills is assumed to be possible as long as

cattle and pig feed is produced in the same production lines, and premises.

• Cross-contamination during transport is possible, particularly if the same trucks are

used for transporting ruminant MBM (RMBM) and non-ruminant MBM (porcine or

poultry MBM which still might be included into cattle feed) or for transporting

pig/poultry feed and cattle feed.

• On-farm cross-contamination is regarded to be possible.

• Cross-contamination of cattle feed with RMBM can not be excluded. Hence, as

reasonable worst case scenario, it has to be assumed that cattle, in particular dairy

cattle, can still be exposed to RMBM and hence to BSE-infectivity, should it enter

the feed chain.

Control of Feed bans and cross-contamination

• With the introduction of the RMBM ban (1997) the feed mills (approximately 600)

were checked for compliance with the ban, including good manufacturing practices

(GMP) and record keeping, i.e. the separation in production of MBM containing

ruminant material (RMBM) from non-ruminant MBM.

• The feed mills had previously – since 1983 – been regularly checked in relation to

production of medicated feed.

• No examinations are performed to assess cross-contamination with RMBM of the

protein (e.g. non ruminant MBM) that enters cattle feed. Differentiation would

anyway be difficult.

Rendering

Raw material used for rendering

• Ruminant material is rendered together with material from other species, but

according to the CD only in the production of MBM prohibited for use in ruminant

feeds.

• Slaughter by-products, including specified risk material (SRM) and fallen stock are

rendered.

• The country expert estimated that 20% of the rendering plants, processing 20% of

the total amount of raw material, are connected to slaughterhouses. Their raw

material is more than 98 % animal waste from these slaughterhouses while less than

2 % is fallen stock. No estimation was given for the remaining 80% of the rendering

capacity.

• There are 32 rendering plants of which 3 are processing blood exclusively.

Rendering processes

• The rendering systems (parameters) were specified for 6 plants producing mixed

MBM, none of these fulfilled the 133/20/3 standard. Of these, 5 have dedicated

facilities to produce products for use in ruminant feed and products not permitted for

use in ruminant feed.

• The remaining plants process porcine or poultry material exclusively.

SRM and fallen stock

• There is an SRM ban for human food in place since 2003.

Annex to the EFSA Scientific Report (2004) 2, 1-15 on the Assessment of the

Geographical BSE Risk of Canada

- 10 -

• However, SRM are rendered together with other slaughter waste and fallen stock.

However, according to the CD, MBM with SRM is not permitted to be fed to

ruminants.

Conclusion on the ability to avoid recycling

• Between 1980 and 1997 the Canadian system would not have been able to avoid

recycling of the BSE-agent to any measurable extent. If the BSE-agent was

introduced into the feed chain, it could have reached cattle.

• Since 1997 this ability gradually improved with the introduction of the ruminant

MBM ban and its implementation.

• Since cross-contamination cannot be excluded, and as SRM is still rendered by

processes unable to significantly reduce BSE-infectivity, the system is still unable to

avoid recycling of BSE-infectivity already present in the system or incoming.

3.2 Overall appreciation of the ability to identify BSE-cases and to

eliminate animals at risk of being infected before they are processed

Cattle population structure

• Cattle population: 12.15 Million in 1988 increasing to 14.6 Million in 2001;

• Of the total cattle population, 2.2 million are dairy cattle and 12.4 million are beef.

• The cattle population above 24 months of age: approx. 6.0 Million.

• Of the approximately 2.2 Million dairy cattle 2 Million are located in the two eastern

provinces Ontario and Quebec.

• Mixed farming (cattle and mono-gastric species) is usually not practiced; the

country expert estimated the proportion of mixed farming to be less than 1%.

• Individual regions traditionally have ID systems under provincial authorities. Brand

inspectors are present when cattle are assembled. It is estimated by the Canadians

that the level of a national, uniform ID for cattle is less than 10%; most of those

individual pedigree animals. Mandatory ID for the milk-fed veal sector was

implemented in Quebec in 1996, but does not contain information on the herd of

origin. An agreement of the relevant industries to develop a national cattle ID and

trace back strategy was reached on 1 May 1998 (starting in 2001).Since 2002, a

national identification program is existing. Al cattle leaving any farm premises must

be uniquely identified by ear tag.

BSE surveillance

• BSE was made notifiable in 1990.

• Every cow over one year of age exhibiting central nervous system signs suggestive

of BSE submitted to a laboratory or presented at an abattoir is subjected to a BSE

laboratory diagnostic test (histology and over the past years also PrPSc-based

laboratory tests).

• In addition, cattle submitted for rabies examination and found rabies negative are

examined for BSE. Samples are prepared immediately upon arrival to the federal

laboratory responsible for the rabies diagnostic for possible later BSE examination,

i.e. formalin fixation.

• Since the 1940’s, a rabies control program has been in place, where farmers,

veterinarians and the general public are well educated about this neurological

Annex to the EFSA Scientific Report (2004) 2, 1-15 on the Assessment of the

Geographical BSE Risk of Canada

- 11 -

disease. In 1990, when BSE was made notifiable, this awareness was extended to

suspicions of BSE.

• Since 1993 the number of brains examined per year did exceed the number

recommended by OIE (300 - 336 for countries with a cattle population over 24

months of age of 5.0 to 7.0 Million) in all years, except in 1995 (table 4).

year 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

samples 225 645 426 269 454 759 940 895 1΄020 1΄581 3΄377 3΄361

Table 4: Number of bovine brains annually examined for CNS diseases, including BSE.

• According to the CD approx. 98% of the examined cattle were older than 24 months

and approx. 90% exhibited neurological symptoms. Although the identification

system of Canada does not document the birth date or age of the animals, according

to the CD, examination of the dentition is used to ascertain the maturity of the

animals.

• The list of neurological differential diagnoses for the 754 brains examined in 1997

included encephalitis (70 cases), encephalomalacia (19), hemophilus (7),

hemorrhage (2), listeriosis (38), meningoencephalitis (36), rabies (22), tumors (2),

other conditions (135) and no significant findings (423).

• Compensation is paid for suspect BSE cases as well as for animals ordered to be

destroyed (90-95% of market value with a maximum of 2,500 Can$ per cow).

• Diagnostic criteria developed in the United Kingdom are followed at ADRI,

Nepean. According to the very detailed protocol for the collection, fixation and

submission of Bovine Spongiform Encephalopathy (BSE) specimens at abattoirs

under inspection by the Canadian Food Inspection Agency, the specimen shall be

shipped to National Center for Foreign Animal Disease, Winnipeg, Manitoba.

• In 2003, around 3000 animals from risk populations have been tested.

• According to the CD, it is aimed to test a minimum of 8000 risk animals (animals

with clinical signs consistent with BSE, downer cows, animals died on farm animals

diseased or euthanized because of serious illness) in 2004 and then continue to

progressively increase the level of testing to 30,000.

• In May 2003, Canada reported its first case of domestic BSE. A second case was

detected in the US on 23 December 2003 and traced back to Canadian origin. Both

were born before the feed ban and originated from Western Canada.

3.3 Overall assessment of the stability

For the overall assessment of the stability, the impact of the three main stability factors

(i.e. feeding, rendering and SRM-removal) and of the additional stability factor,

surveillance, has to be estimated. Again, the guidance provided by the SSC in its

opinion on the GBR of July 2000 (as updated January 2002) is applied.

Feeding

Until 1997, it was legally possible to feed ruminant MBM to cattle and a certain fraction of

cattle feed (for calves and dairy cattle) is assumed to have contained MBM. Therefore

feeding was "Not OK". In August 1997 a ruminant MBM ban was introduced but feeding

of non-ruminant MBM to cattle remained legal as well as feeding of ruminant MBM to

non-ruminant animals. This makes control of the feed ban very difficult because laboratory

differentiation between ruminant and non ruminant MBM is difficult if not impossible.

Annex to the EFSA Scientific Report (2004) 2, 1-15 on the Assessment of the

Geographical BSE Risk of Canada

Due to the highly specialised production system in Canada, various mammalian MBM

streams can be separated. Such a feed ban would therefore be assessed as "reasonably

OK", for all regions where this highly specialised system exists. However, several areas

in Canada do have mixed farming and mixed feed mills, and in such regions, an RMBM

ban would not suffice. Additionally, official controls for cattle feeds to control for the

compliance with the ban were not started until the end of 2003. Thus, for the whole

country, the assessment of the feeding after 1997 remains "Not OK".

Rendering

The rendering industry is operating with processes that are not known to reduce infectivity.

It is therefore concluded that the rendering was and is "Not OK".

SRM-removal

SRM and fallen stock were and are rendered for feed. Therefore SRM-removal is assessed

as "Not OK"

snip...

4.2 Risk that BSE infectivity entered processing

A certain risk that BSE-infected cattle entered processing in Canada, and were at least

partly rendered for feed, occurred in the early 1990s when cattle imported from UK in

the mid 80s could have been slaughtered. This risk continued to exist, and grew

significantly in the mid 90’s when domestic cattle, infected by imported MBM, reached

processing. Given the low stability of the system, the risk increased over the years with

continued imports of cattle and MBM from BSE risk countries.

4.3 Risk that BSE infectivity was recycled and propagated

A risk that BSE-infectivity was recycled and propagated exists since a processing risk

first appeared; i.e. in the early 90s. Until today this risk persists and increases fast

because of the extremely unstable BSE/cattle system in Canada.

5. CONCLUSION ON THE GEOGRAPHICAL BSE-RISK

5.1 The current GBR as function of the past stability and challenge

The current geographical BSE-risk (GBR) level is III, i.e. it is confirmed at a lower level

that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent.

This assessment deviates from the previous assessment (SSC opinion, 2000) because at

that time several exporting countries were not considered a potential risk.

snip...

full text;


http://www.efsa.eu.int/science/efsa_scientific_reports/gbr_assessments/scr_annexes/563/sr02_biohaz02_canada_report_annex_en1.pdf




EFSA Scientific Report on the Assessment of the Geographical BSE-Risk (GBR) of the United States of America (USA)
Publication date: 20 August 2004
Adopted July 2004 (Question N° EFSA-Q-2003-083)

Report

Summary
Summary of the Scientific Report

The European Food Safety Authority and its Scientific Expert Working Group on the Assessment of the Geographical Bovine Spongiform Encephalopathy (BSE) Risk (GBR) were asked by the European Commission (EC) to provide an up-to-date scientific report on the GBR in the United States of America, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in USA. This scientific report addresses the GBR of USA as assessed in 2004 based on data covering the period 1980-2003.

The BSE agent was probably imported into USA and could have reached domestic cattle in the middle of the eighties. These cattle imported in the mid eighties could have been rendered in the late eighties and therefore led to an internal challenge in the early nineties. It is possible that imported meat and bone meal (MBM) into the USA reached domestic cattle and leads to an internal challenge in the early nineties.

A processing risk developed in the late 80s/early 90s when cattle imports from BSE risk countries were slaughtered or died and were processed (partly) into feed, together with some imports of MBM. This risk continued to exist, and grew significantly in the mid 90’s when domestic cattle, infected by imported MBM, reached processing. Given the low stability of the system, the risk increased over the years with continued imports of cattle and MBM from BSE risk countries.

EFSA concludes that the current GBR level of USA is III, i.e. it is likely but not confirmed that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. As long as there are no significant changes in rendering or feeding, the stability remains extremely/very unstable. Thus, the probability of cattle to be (pre-clinically or clinically) infected with the BSE-agent persistently increases.


http://www.efsa.eu.int/science/efsa_scientific_reports/gbr_assessments/573_en.html


TSS



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