SEARCH VEGSOURCE:

 

 

Follow Ups | Post Followup | Back to Discussion Board | VegSource
See spam or
inappropriate posts?
Please let us know.
  




From: TSS ()
Subject: BSE situation and establishment of Food Safety Commission in Japan
Date: January 31, 2006 at 10:26 am PST

J O U R N A L O F

Veterinary

Science

J. Vet. Sci. (2006),

7(1), 1¨C11

BSE situation and establishment of Food Safety Commission in Japan

Takashi Onodera*, Chi-Kyeong Kim

Department of Molecular Immunology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi 1-1-1,

Tokyo 113-8657, Japan

Eight major policies were implemented by Japanese

Government since Oct. 2001, to deal with bovine spongiform

encephalopathy (BSE). These are; 1) Surveillance in farm

by veterinarian, 2) Prion test at healthy 1.3mi cows/yr, by

veterinarian, 3) Elimination of specified risk material

(SRM), 4) Ban of MBM for production, sale use, 5) Prion

test for fallen stocks, 6) Transparent information and

traceability, 7) New Measures such as Food Safety Basic

Law, and 8) Establish of Food Safety Commission in the

Cabinet Office. At this moment, the extent of SRM risk

has only been indicated by several reports employing tests

with a limited sensitivity. There is still a possibility that

the items in the SRM list will increase in the future, and

this indiscriminately applies to Japanese cattle as well.

Although current practices of SRM elimination partially

guarantee total food safety, additional latent problems

and imminent issues remain as potential headaches to be

addressed. If the index of SRM elimination cannot

guarantee reliable food safety, we have but to resort to

total elimination of tissues from high risk-bearing and

BSE-infected animals. However, current BSE tests have

their limitations and can not yet completely detect highrisk

and/or infected animals. Under such circumstances,

tissues/wastes and remains of diseased, affected fallen

stocks and cohort animals have to be eliminated to

prevent BSE invading the human food chain systems. The

failure to detect any cohort should never be allowed to

occur, and with regular and persistent updating of

available stringent records, we are at least adopting the

correct and useful approach as a reawakening strategy to

securing food safety. In this perspective, traceability based

on a National Identification System is required.

Key words: bovine spongiform encephalopathy, BSE, Food

Safety Comission, specified risk material, surveillance test,

traceability

Introduction

In April 1985 the first cases in the United Kingdom of a

new disease of cattle were seen; bovine spongiform

encephalopathy (BSE) which has commonly become known

as ¡°mad cow disease.¡± This disease was characterized by

gray matter vacuolation and fibrils similar to those observed

in sheep scrapie [10,20]. Epidemiological studies established

the most probable cause of the outbreak of the new disease

as changes in the rendering process for the offal used in

animal feed. This allowed some agent-either scrapie agent

from infected sheep carcasses or a previously uncharacterized

BSE agent-to contaminate high protein cattle feed [22,24].

Between 1981 and 1982 most of the rendering plants had

changed their process such that there was no longer a solvent

based fat-extraction step followed by steam distillation of

the solvent. Solvents have been shown to inactivate the

scrapie agent [8]. Without the steam distillation step, the

offal failed to reach the high steam temperature known to

destroy the scrapie agent (138oC for 1 hour 3 bars) [3,8,19].

The change in offal processing preceded the subsequent

outbreak of BSE in 1986-7. It is possible that the agent was

always present in this type of feed, but that the reduction in

fat content with hydrocarbons and the subsequent steam

treatment of the product kept the number of infectious

particles down so that a clinical disease was not seen (the

disease symptoms being dose related). In Scotland, where

the hydrocarbon extraction continued to be used during high

protein feed production, the number cases of BSE was

significantly fewer per head of cattle in England [23].

The magnitude of the BSE epidemic was probably

amplified by infected cattle being included in the rendering

process. It does appear, however, that BSE is not readily

transmitted either horizontally or vertically [21], and as a

result of feed ban in July 1988 the size of the epidemic has

been self-limiting to a large extent [24]. Indeed, the incidence

of disease in cattle born after the feed ban took effect has

dropped dramatically through years [23,24]. However, it is

not clear whether or not maternal transmission of BSE does

occur [9].

The start of the BSE epidemic was followed by reports of

*Corresponding author

Tel: +81-3-5841-5196, Fax: +81-3-5841-8020

E-mail: aonoder@mail.ecc.u-tokyo.ac.jp

Review

2 Takashi Onodera, Chi-Kyeong Kim

spongiform encephalopathies in a variety of animals including

many exotic animals housed in zoos and wildlife parks

[7,12,15,26]. These infections were all associated with

ruminant-derived feed [13] or from maternal transmission

[12]. These infections all produced the same lesion profiles

when injected into mice as BSE and feline spongiform

encephalopathy (FSE) [4]. The transmission of spongiform

encephalopathy across the species barrier by oral dosing is

of great concern to the government in all over the world.

However, it appears that primates are protected by a

considerable species barrier; indeed from transmission data

with marmoset, primates are more likely to contact scrapie

than BSE [1]. Since epidemiological studies have never

linked human transmissible spongiform encephalopathy

(TSE) with exposure to sheep scrapie and transgenic mice

expressing that human prion protein (PrP) are not more

susceptible to BSE than non-transgenic controls [6] it is

possible that humans are not threatened by BSE zoonosis. In

early 1996, however, the CJD (Creutzfeldt-Jakob disease)

Surveillance Unit reported ten cases of a human TSE; CJD

in unusually young patients [25], which prompted the

European Union (EU) to ban export of British beef and beef

derived products in world-wide. Mouse transmission and

strain typing studies from four of these cases are performed

at the Institute of Animal Health. These results showed the

same lesion profiles when injected info mice as BSE [2,5].

In this review cases of Japanese BSE are reported. Risk

Assessment and Risk Management in the Japanese BSE

incidents are discussed.

History of Japanese BSE

In January 2001, Japan banned the import of beef and

processed beef products from 18 countries, including those

in EU, to prevent BSE from entering Japan. Scientific

Steering Committee (SSC), which is in charge of nutritional

safety in the EU, evaluated the risk-level of BSE in Japan as

three on a scale of one to four according to the sources close

to the SSC, but the report has yet to materialize.

On August 6, 2001, one five-year-old milking cow was

slaughtered at the abattoir which showed difficulty in

standing. We examined the brain at the National Institute of

Animal Health (NIAH) and according to the results, we

confirmed August 15 it was negative, but later on, we

carried out brain tissue tests in which we found spongy

lesions in the tissue of the brain (Table 1).

The sample was delivered to the Institute again, and the

Institute confirmed the presence of the holes, and then we

confirmed signs of (BSE) positive on September 10 through

another test, such as Bio-Rad ELISA and Prionics.

British government scientists determined that a 5-year-old

Holstein at a dairy farm in Shiroi, near Tokyo, carried the

disease, formally called bovine spongiform encephalopathy,

or BSE.

Accordingly, Japanese Government, Ministry of Agriculture,

Forestry and Fisheries (MAFF) reported first Japanese Case

to OIE (World Organization for Animal Health), as written

below.

Disease Name: Bovine Spongiform Encephalopathy

(suspicion) Code: B115

Suspicion: A five year old Holstein cow kept on a dairy

farm in Chiba prefecture was slaughtered on 6 August 2001

at an abattoir. As the cow had dystacia, a brain sample was

taken and sent to the National Institute of Animal Health and

subjected to Prionics Check Test with a negative result on 15

August. A brain sample from this cow was also sent to the

prefecture Livestock Hygiene Service Center and subjected

to histopathological examination and found to have vacuoles

Table 1. Chronology of BSE measures: Measures taken before the detection of the first case of BSE

1951 Import of Beef prohibited from Great Britain for foot and mouth disease reasons

Jul. 1990 Import of live cattle prohibited from the United Kingdom (UK) and other countries with incidence of BSE

except for MBM heat-treated at 136oC/30 minutes in steam

Mar. 1996 Import of MBM from the UK totally prohibited

Import of beef and its products prohibited from the UK

Apr. 1996 Administrative guidance issued to prohibit the use of ruminant MBM for ruminant feed

Jan. 2001 Import of MBM from the European Union Member States, Switzerland and Liechtenstein prohibited

Apr. 2001 Domestic BSE surveillance strengthened

Sep. 2001 First case of BSE detected

Sep. 2001 Legal prohibition on use of ruminant MBM for ruminant feed

Sep. 2001 SRM removal from all cattle for human consumption

Oct. 2001 Import of processed animal protein prohibited from all countries

Oct. 2001 Legal prohibition on use of processed animal protein for feed and fertilizer

Oct. 2001 BSE testing on all cattle for human consumption

Oct. 2001 Domestic surveillance strengthened

Dec. 2001 Import of powdered animal fat prohibited from all countries

Jan. 2002 Use of ruminant animal fat with impurity over 0.02% for milk replacer prohibited

BSE situation in Japan 3

on 24 August. The same brain sample was sent to the NIAH

on 6 September for histopathological examination with the

same result. The same sample was subjected to immunohistochemical

examination with a positive result on 10

September.

Measures taken: Immediately after the BSE is suspected,

the herd has been placed under quarantine by the prefecture

veterinary inspector.

On October 2 Ministry of Health, Labor and Welfare

(MHLW) asked processed food manufacturers to stop using

extract or enriched additives, such as beef essence and

collagen, from cattle meat and bone as they may contain a

pathogen that causes variant CJD (vCJD).

In November of 2001 beef prices in Tokyo have plummeted

by 20 percent, and meat packing companies have started

prominently labeling their imported beef as domestic beef,

because Japanese Government compensated for their beef

processed before October 18.

On December 1 the cow, slaughtered at a meat processing

plant in Saitama Prefecture, is expected to be declared the

nation¡¯s third case of BSE - following infected dairy cows

found in Shiroi, Chiba Prefecture and Sarufutsu-mura,

Hokkaido - at the meeting of experts. According to the

ministry, the cow was raised by a dairy farmer in Miyagimura,

Gumma Prefecture. When it turned five years and

eight months of age, which is old for a dairy cow, it was sent

to the slaughter house. The cow was tested for BSE before it

was processed, but the test did not show anything clinically

unusual, the officials said. However, after it was slaughtered,

two tests on materials from the cow using the ELISA

resulted in positive reactions on the same day. The test was

conducted at a meat hygiene inspection center in Saitama.

The MHLW Yokohama quarantine center conducted another

test next day using the more accurate Western blot method,

and the result was also positive.

On December 21 the Japanese Ministry then asked the EU

to draw up another risk-assessment for BSE since Japan

would be automatically designated as a country at high risk

if Tokyo fails to make the request by the end of the year. In

Japan, if you want consumers to regain confidence in meat

products, you need absolute transparency, accountability

and a trustworthy control system through the whole process

(from breeding the cattle to inspecting their meat).

On December 25, 2001, in Japan, a poll conducted December

15-16 by the Yomiuri Shimbun newspaper found 68% of

Japanese have stopped eating meat or are eating less beef

since the farm ministry confirmed the first case of the

disease in a cow in Chiba Prefecture on September 22.

Farm ministry investigations in September found 165

households in 15 prefectures in Japan engaged in livestock

farming had fed MBM, as well as blood and bone meal feed,

to a total of 5,129 cows. MBM was then officially banned

for use in feeding cattle on September 18. It was also banned

for other livestock on October 15.

Japanese Government Policy

Eight major policies were implemented since October 2001.

1) Surveillance in farm by veterinarian, 4.5mi cows/yr.

2) Prion test at healthy 1.3mi cows/yr. at this time there is

no tracing system.

3) Elimination of SRM(specified risk material)

4) Ban of MBM (meat- and - bone meals) for production,

sale use.

5) Prion test for fallen stocks. 100,000 cows (aged more

than 24 months old)/yr. tests.

6) Transparent information and traceability.

7) New Measures

Food Safety Basic Law.

Details of Law is shown in the website of Japanese

Government (http://www.fsc.go.jp/english/index.html).

8) Government Reorganization (Food Safety Commission:

FSC) (Table 2). Details of organization of FSC is shown

in the same website (http://www.fsc.go.jp/english/index.

html).

SRM removal

Removal of SRMs has been mandatory since October

2001, and being carried out at all slaughterhouses in Japan, as

of March 2005. SRM removal is believed to cut the infectious

doses by 99.4%. Therefore, if SRMs can be removed with

complete certainty, the risk of meat becoming contaminated

by BSE prions can be reduced dramatically [17].

In Japan, use of cattle heads (excluding the tongue and

cheek flesh), spinal cord, distal part of ileum, spinal column

including dorsal root ganglion for food products is prohibited

for all cattle by the law. However, it is not practical to consider

that a complete SRM removal is implemented in slaughter

houses because of the residual spinal cord left behind during

spinal cord removal, possible contamination of dressed

carcasses, and contamination of central nervous tissues by

pitching. The result of surveillance concerning the removal

rates of spinal cord before back-spreading in 7 Meat Hygiene

Inspection Office directed by NHLW are as follows: 5 offices

employing the spinal cord aspiration method indicated

average 80.6 ¡À 17.1% (52.5~ 99.1%) and 2 offices employing

the spinal cord extrusion method indicated average 75%

(72.0, 78.0%). In addition, the residual spinal cord after backspreading

was disposed of manually [28].

Absence or presence of tissues other than SRM in which

abnormal prion protein accumulates cannot be determined at

this point because of the detection limit of the infection

experiments by which SRM was identified and uncertainity

derived from incomplete understanding of mechanisms

underlying BSE infection. These ideas are supposed to be

the grounds on which the World Health Organization

recommends exclusion of any BSE-cattle tissue from the

human food chain.

4 Takashi Onodera, Chi-Kyeong Kim

Traceability

In Japan, in December 2003, based on the ¡°Special measures

law on management and transmission of information for

individual recognition of cattle¡±, the traceability system has

been made compulsory to document information, including

birth record, which allows individual recognition at the

production and slaughtering stages and determination of

accurate ages. This allows a separate investigation on the

degree of risk of BSE infections before or after implementation

of various regulation.

Table 2. Advisory committees

Food Safety Commission Expert Committee on Prions (chaired by Prof. Yoshikawa)

MAFF Advisory Committee on Food, Agriculture and Rural Policy¡¯s Subcommittee on Prion Diseases

(Chaired by Prof. Onodera)

BSE Policy Advisory Group (chaired by Prof. Kumagai)

MHLW Advisory Committee on Pharmaceutical Affairs and Food Sanitation¡¯s TSE Group on Food Sanitation

(chaired by Prof. Shinagawa)

Expert Committee on BSE Diagnosis (chaired by Prof. Shinagawa)

Advisory Committee on Pharmaceutical Affairs and Food Sanitation¡¯s TSE Group on Pharmaceutical

Affairs (chaired by Dr. Yosikura)

Organization of the Food Safety Commission

1. Academic Background of Commission Members (Seven Commission Members total, including four full-time members and three

part-time members)

Masaaki Terada (Chairman)

Tadao Terao (Deputy Chairman)

Naoko Koizumi

Takeshi Mikami

Motoko Sakamato

Seiichi Honma

Yasuhiko Nakamura

2. Organization of the Food Safety Commission (Expert Commission Members will total around 200)

Food Safety Commission

Planning

Risk communication

Emergency Response (food accidents, etc)

(Assessment team)

Chemical substance assessment group

Food additives Pesticides

Veterinary Medicines Apparatus / containers and packages

Chemical substance Contaminants, etc.

Biological assessment group

Microorganisms Virus

Natural toxins/mycotoxins, etc. Prions (BSE, etc.)

Emerging food assessment group

Genetically modified organisms Newly developed foods

Feed/fertilizer, etc.

3. Organization of the Secretariat (Secretariat personnel: 54)

Secretariat (Director-General, Deputy Director-General, and four divisions and one director

General Affairs Division

Risk Assessment Division

Recommendation and Public Relations Division

Information and Emergency Response Division

Director for risk communication

BSE situation in Japan 5

In addition, this regulation has also been implemented at

the distribution level since December 2004. Taking into

account its significance to create transparency for consumer

to directly obtain information of beef, securing and verification

of the traceability system are deemed essential from now on.

Risk management

While BSE in cattle was first reported in 1986 in the

United Kingdom, the first case in Japan was not detected

until 2001. Since then, the Japanese Government has

intensified BSE surveillance in cattle and located 19 more

cases in subsequent years (Table 3).

The experience in continental Europe shows that a

comprehensive strategy in combating BSE is not available on

the drawing board. Measures taken to resolve BSE incidences

in Japan have to be persistently assessed, systematically

modified and appropriately adapted to conditions in Japan.

As the first country to have detected BSE cases in Asia,

Japan was obligated to promptly implement a variety of

countermeasures after encountering the first BSE cases in

cattle. Of many countermeasures, the most important

approach focused on the feed issue; prompt imposition of a

ban on specified high-risk raw materials such as brain- and

spinal cord-derived meals was quickly adopted. Apart from

the feed issue, we are still continuing to incorporate

additional measures to neutralize BSE in Japan.

All the 20 BSE cases that have been diagnosed up to

October 2005 were dairy cows. Of these, 16 cases were

located at slaughterhouses while the remaining 4 cases were

fallen farm-stock. Since unregulated imports of MBM from

BSE-affected countries into Japan had been practiced

extensively in the 80s and early 90s, contaminated feed were

likely given to animals. If infected animals had not been

diagnosed then, they might be eventually terminated as feed

(SRM) and could have yielded domestically infected MBM;

A raw material which is churned into homemade MBM

would serve as a possible source of BSE dissemination in

Japan.

The controversy in OIE recommendations of import and

export of beef are the basics for conflicts within the framework

of WTO/SPS (sanitary and phytosanitary agreement): if

measures more stringent than the OIE recommendations are

adopted, scientific arguments (risk assessment) have to be

provided. While risk assessments for different countries are

under evaluation, the GBR (geographical BSE risk) -

assessment of the EU is currently being considered. With

regard to the import bans - especially concerning beef - the

risks of communication are very problematic. If Japanese

beef is considered safe for consumption, it is difficult then to

explain the status of American beef as being more risky than

Japanese beef.

For the measures concerning consumer protection, we are

considering a re-evaluation of the approach to testing young

cattle. As suggested by some Swiss scientists, we have to

provide details of the limitations of the test to consumers/

retailers. Instead of beef, the brain of animals is tested with

the possibility of detecting relevant BSE agents within the

brain tissues, which in young animals approximates to zero.

In fact, we are currently reviewing pithing in the slaughterhouse.

Beginning in 2004, we have implemented surveillance of

all fallen stock (100,000 tests for cattle over 24 months of

age) to establish an overall status of BSE-infection in Japan.

The European experience has revealed that risk-bearing

BSE cases harbor the infected animals (with clinical signs of

BSE) in fallen stock and slaughtered adult cattle related to

emergency/diseases; the probability of BSE infection in the

risk-bearing population (including fallen stocks and emergency/

disease-induced slaughtered adult cattle) is in fact 20 times

higher than that of the normally slaughtered adult population.

In our attempt to correlate the BSE incidence in risk-bearing

populations, details of the actual fallen stock and emergency/

disease-induced slaughtered adult cattle in Japan are now

being reviewed.

After the finding of a BSE case in the United States (U.S.),

an Ad Hoc Subcommittee (in response to BSE in the U.S.)

of the Foreign Animal and Poultry Disease Advisory

Committee was formed. The said subcommittee convened

in Washington D.C. under the chairmanship of Prof. U.

Kihm (Switzerland), and according to his report delivered to

US government and explained in the Japanese FSC in

March 2004, he recommended 5 objectives: ¢Ù reduce the

risk of public health for consumer protection; ¢Ú limit

recycling and amplification of BSE agents; ¢Û establish the

level of effectiveness of measures through surveillance; ¢Ü

prevent any advertent introduction of BSE from abroad in

the future; and ¢Ý contribute to prevention of the epidemic

on a global scale.

The proposed U.S. ban on SRM eliminates high-risk BSE

tissues (i.e. SRM from cattle over 30 months of age) from

food supplies to humans in accordance to the OIE standards.

However, the said subcommittee recommended that specified

SRM (derived from brains and spinal cords of cattle over 12

months of age) be excluded from both the human food chain

and animal feed production lines. Until the levels of BSE

risk have been established, the subcommittee meanwhile

concedes that exclusion of central nervous system tissues,

skulls and vertebral columns from cattle over 30 months of

age as well as intestines from cattle of all ages for use in

human food is a temporary rational compromise.

For the purpose of facilitating overall surveillance reliability,

said subcommittee recommends testing all cattle older than

30 months of age in the above-mentioned high-risk populations,

besides strengthening the passive surveillance system.

Moreover, said subcommittee considers testing of all cattle

slaughtered for human consumption (performed in Japan) to

be unjustified in terms of protecting human and animal

health. However, to support the overall surveillance system

6 Takashi Onodera, Chi-Kyeong Kim

Table 3. BSE cases in Japan as of August 2005

Case

No.

Date of BSE

confirmed

Location of origin Date of birth

Ageb)

(in

month)

Clinical

signs of

BSEb)

Disposition

location

Clinical conditions etc.

(before BSE test)

1 Sep. 11, 2001a)Shiroi city , Chiba pref.

(Originated from)

Saroma, Hokkaido

Mar 26, 1996 65 -d) Abattoir Dystasia due to septicemia

2 Nov. 21, 2001 Sarufutsu village, Hokkaido Apr 4, 1996 67 - Abattoir Leak milk from pilla mammae

fistulation

3 Dec. 2, 2001 Miyagi village, Gunma pref. Mar 26, 1996 68 - Abattoir Reproductive disturbance

4 May 13, 2002 Onbetsu, Hokkaido Mar 23, 1996 73 - Abattoir Dystasia due to myorrhexis in

left foreleg

5 Aug. 23, 2002 Isehara city, Kanagawa pref. Dec 5, 1995 80 - Abattoir Dystasia due to dislocation of

the hip joint at the time of

loading

6 Jan. 20, 2003 Kokawa, Naka county,

Wakayama pref.

Feb 10, 1996 83 - Abattoir The animal fell in the abattoir

and became dysstasia.

(Originated from)

Shibecha, Hokkaido

7 Jan. 23, 2003 Abashiri city, Hokkaido Mar 28, 1996 81 - Abattoir Mastitis and reproductive

disturbance (Originated from)

Yuubetsu, Monbetsu county,

Hokkaido

8 Oct. 7, 2003 (Feedlot)

Katsurao village, Fukushima pref.

Oct 13, 2001 23 - Abattoir -d)

(Calf feeder)

Ohtawara city, Tochigi pref.

(Originated from)

Shioya, Tochigi pref.

9 Nov. 4, 2003 (Calf feeder and feedlot)

Fukuyama city, Hiroshima pref.

Jan 13, 2002 21 - Abattoir -

(Originated from)

Hikami county, Hyogo pref.

10 Feb. 22, 2004 Hiratsuka city, Kanagawa pref. Mar 17, 1996 95 - Abattoir Dystasia due to dislocation of

the hip joint (Originated from)

Hatano city, Kanagawa pref.

11 Mar. 9, 2004 Shibecha, Hokkaido Apr 8, 1996 94 - LHSCc) Dystasia due to dislocation of

the hip joint

12 Sep. 13, 2004 Shisui, Kikuchi county, Kumamoto

pref.

Jul 13, 1999 62 - Abattoir -

13 Sep. 23, 2004 Shinjo, Kitakatsuragi county, Nara

pref.

Feb 18, 1996 103 - Abattoir Dystasia due to dislocation of

the hip joint

(Originated from)

Shihoro, Kato county, Hokkaido

14 Oct. 14, 2004 Shikaoi, Kato county, Hokkaido Oct 8, 2000 48 - LHSC Dead from suffocation

15 Oct. 15, 2004 Honbetsu, Nakagawa county,

Hokkaido

Aug 5, 1996 102 - LHSC Arthritis

16 Mar. 27, 2005 Teshio, Teshio county, Hokkaido Mar 8, 1996 108 - Abattoir -

17 Apr. 8, 2005 Otofuke, Kato county, Hokkaido Sep 11, 2000 54 - LHSC Dystasia and tremor

18 May 12, 2005 Sunagawa, Hokkaido Aug 31, 1999 68 - Abattoir Dystasia due to dislocation of

the hip joint

19 Jun 3, 2005 Betsukai, Notsuke county, Hokkaido Apr 16, 1996 109 - Abattoir -

20 Jun 6, 2005 Shikaoi, Kato county, Hokkaido Aug 12, 2000 57 - Abattoir -

a)Confirmed BSE positive in Japan (It was also confirmed by Veterinary Laboratories Agency of the UK on Sep 21, 2001.).

b)At the time of BSE test.

c)Livestock health service center.

d)Not particular.

BSE situation in Japan 7

and encourage reporting to authorities at the farm level,

random testing of healthy slaughtered cattle over 30 months

of age should be strongly considered.

Said subcommittee acknowledges that the authorities have

recognized the importance of effective identification and

traceability systems, which usefully furnish not only the

cost-effective means of rapidly tracing affected animals but

for government compliance of said recommendations.

Since the outbreak of BSE in the U.S. a trade issue on

dairy and beef products between the U.S. and Japan has

developed. With regard to this issue, a Japan-U.S. BSE

working group was established, and a final report was

compiled on July 22, 2004. In this report, Japan asserts that

the objectives of BSE testing are the elimination of infected

cattle from the food chain to ensure the safety of meat for

consumption. Meanwhile, the U.S. affirms that the OIE

recognized the objectives of BSE testing to help define

whether BSE is present in the U.S. cattle population, and if

so, provide estimates of the level of BSE and monitor the

effectiveness of BSE prevention and control measures.

Taking into account the fact that the detection of abnormal

prion proteins under a certain age (in months) is difficult

through BSE testing, we emphasized implementation of a

double check where SRM from all cattle should be removed

to compensate for technical limitations of the testing as a

fail-safe measure. Moreover, the U.S. reaffirms that SMR

removal is indeed the best way to protect consumers from

exposure to abattoir-derived BSE-infected cattle.

In this perspective, Japan and the U.S. agreed that SRM

should be removed in such a manner as to avoid crosscontamination

of edible tissue during slaughter, dressing,

and processing. Removed SRM should be disposed of

according to laws of the respective countries. The U.S.

explained that the quality systems verification program of its

Agriculture Marketing Service (AMS) is used to provide

independent verification of industry management systems

and other quality standards. This program could provide

assurances that U.S. beef exported to Japan meets the

prescribed safety requirements.

In this report, the U.S. provided scientific documentation

that clearly demonstrated that cattle could be accurately

monitored to ages of 30 months and more. In addition, the

U.S. is embarking on a National Animal Identification System,

whereby the age-in-month and identification of cattle can be

precisely traced. The AMS quality systems verification

programme can be used to certify exported beef and beef

products that satisfied meat conditions required by Japan

and the U.S. regulatory requirements.

Through discussion of a spectrum of controversial

subjects within the working group, both parties converged

on the following major requirements: ¢Ù that there is a

limitation to 100% testing of consumption-destined animals;

¢Ú SRM elimination is extremely important for food safety;

and ¢Û the risks of contamination by SRM in abattoirs have

be neutralized. Other remaining subjects are opened for

future discussion.

Because the media assumed that the Japan-U.S. negotiations

focused merely on BSE testing and SRM elimination, they

misinterpreted that the Japanese market was then opened to

American beef when FSC agreed to the limitation of animal

testing, and the ages for SRM elimination. They might have

been misled by the emphasis of major issues on these two

subjects in previous reports.

Along the same line of thought, the Japanese Consumer

Association (JCA) misconceived that BSE-testing and SRM

elimination were the basic measures for securing the safety

of beef for consumption. In fact, some in the JCA are still

insisting that ¡°100% BSE-testing¡± is a prerequisite for the

importation and distribution of domestic beef for consumption

in Japan. Although the FSC has yet to make up its mind on

abbreviation of the BSE-testing in young cattle, I would like

to emphasize that there is no scientific basis to continue with

the 100% BSE-test for securing the food safety levels for

beef and relevant edible bovine products. Elimination of

SRM can not guarantee the total safety of beef. At this

moment, the extent of SRM risk has only been indicated by

several reports employing tests with a limited sensitivity.

There is still a possibility that the items in the SRM list will

increase in the future, and this indiscriminately applies to

Japanese cattle as well. Although current practices of SRM

elimination partially guarantee total food safety, additional

latent problems and imminent issues remain as potential

headaches to be addressed. If the index of SRM elimination

can not guarantee reliable food safety, we have but to resort

to total elimination of tissues from high risk-bearing and

BSE-infected animals. However, current BSE tests have

their limitations and can not yet completely detect high-risk

and/or infected animals. Under such circumstances, tissues/

wastes and remains of diseased, affected fallen stocks and

cohort animals have to be eliminated to prevent BSE invading

the human food chain systems. The failure to detect any

cohort should never be allowed to occur, and with regular

and persistent updating of available stringent records, we are

at least adopting the correct and useful approach as a

reawakening strategy to securing food safety. In this

perspective, traceability based on a National Identification

System is required.

Abattoir compliance for the elimination of SRM is an

issue different from cross-contamination of food and animal

feed during processing. Restriction of this information

coupled with limited communications on imminent risks

may inflict damage on humans in a ¡°worse and belated¡±

fashion. Therefore, we have to stipulate guidelines for securing/

standardizing food safety based on guaranteed traceability,

elimination of cross-contamination of food and feed, as well

as BSE-testing and abattoir compliances for total SRM

elimination.

8 Takashi Onodera, Chi-Kyeong Kim

Control measures taken by Japanese government

OIE code requires the implementation of control measures

as follows,

- public awareness programs and contingency plans for

BSE.

- ban on feeding animals with ruminant by-products.

- bovine spongiform encephalopathy surveillance programs.

- diagnostic services, including the result of tests for BSE

and transmissible spongiform encephalopathy (TSEs).

Details of measures are described accordingly.

A. Public awareness: programs and contingency programs

The public awareness programs include training courses,

mass-communication media, publications, internet systems

and meetings, but well organized awareness campaign seems

to be required even in Japan. A contingency plan is available

in the government office. It is considered essential to test the

plans through stimulation exercises and training courses at

regular intervals, and to review the plans annually.

B. Ban on feeding ruminants with feed stuffs derived from

ruminants

In 1996, official instruction prohibited the use of feeds

derived from ruminants. However, implementation of this

official instruction is apparently incomplete. In 2001, a legal

ban was imposed on feeds containing proteins from

mammals for feeding ruminants (Fig. 1). In April 1996, the

Government issued an administrative guidance banning the

use of products containing ruminant animal tissues, such as

MBM in feed for ruminant animals. With regard to imported

feed, even before October 2001, every feed importer has

been obligated by Feed Safety Law to submit information

including its name, the kinds of feed it imports and other

details. However, because of compound feed production

relies heavily on imported ingredients an accurate grasp of

the extent of worldwide BSE contamination is lacking, raw

materials used to manufacture compound and mixed feed

will be added to risk factor. The use of MBM has been

completely banned since October 2001.

C. Rendering of ruminant by-products

There are 21 rendering plants in Japan and approximately

320,000 tones for cattle, 704,000 tones for cattle, 576,000 tones

of pig and 576,000 tones of poultry are rendered annually. Only

3.4% to 13.4% of these materials are steam-heated at 133oC for

20 min at a pressure of 3 bar. OIE codes for production of

bovine MBM require steam-heat at 133oC for 20 min at a

pressure of 3 bar. Even in these condition approximately 0.1%

of BSE agents will survive after the steamed heat.

D. Notification of suspected cases of BSE and scrapie

In 1996 BSE and scrapie are notifiable in Japan and these

have implemented routine surveillance programs [14].

E. Diagnostic services

Japanese Government uses a combination of tests such as

histopathology (HP), enzyme-linked immunosorbent assay

(ELISA), Western blot (WB) and immunohistochemistry

(IHC) (Fig. 2).

National reference laboratory for BSE are located in

Tsukuba: National Institute of Animal Health, and Tokyo:

National Institute of Infectious Diseases. The development

of simplified diagnostic kits for BSE should be encouraged

with a view to reducing the cost of each test so as to

drastically increase the number of tests not only in Japan but

also in surrounding countries.

In May 2001, testing was initiated at slaughterhouses in

Japan on cattle at risk.

Since October 2001, all slaughtered cattle in Japan undergoing

an ELISA screening test, followed by a confirmation test using

the Western blot method and a microscopic pathological/

immunohistochemical examination. As of August 2005,

approximately 5 million animals have undergone testing,

resulting in fifteen cows testing positive for BSE infection.

Investigations for improvement and development of rapid

BSE test methods are being employed in European

countries, the U.S., and Japan. And rapid testing methods

with greater sensitivity are expected to become available. It

is considered that the lower the detection limit is, the

younger the detectable BSE-cattle will be.

Moreover, demonstration of the presence or absence of

infection before slaughtering can be expected if testing using

tissues or blood samples removed from live cattle become

Fig. 1. Regulation of animal feed. In October 2001, usage of

meat- and bone-meal (MBM) for feed has been totally

prohibited. However, securing effectiveness of feed regulations

is required from now on since the possibilities of crosscontamination

in the process of feed production in feed mixture

factories and during the transportation of materials have been

pointed out, by the Epidemiological Surveillance Team of the

MAFF.

BSE situation in Japan 9

available. This will allow the detection and exclusion of

BSE cattle without bringing them into slaughter house and

incurring the risk of SRM cross-contamination, and lead us

close to the goal described in the report (16) by the SSC in

EU: Exclude infected animals from the human food chain to

protect consumers from the risk of BSE infection.

F. Focused efforts on key issues in TSE-research:

Focused efforts in TSE research in Europe will be

supported on a limited number of key issues. The same

manner is applied in Japanese Scientific Society and the

Government. The projects must build critical mass and be

designed to lead to rapid results. Research projects will be

implemented through Concerted Actions, Thematic Networks,

and RTD/Demonstration Projects. Projects should reflect

dedicated efforts that clearly address one of the following

issues:

¢Ù In vivo tests for pre-clinical diagnosis in humans and

animals: Specific, sensitive methods to detect and quantify

prion diseases (e.g. surrogate markers, prion-binding proteins

or receptors, strain typing).

¢Ú Inactivation and prevention: Longevity of the agent

including natural conditions (e.g. in pastures and soils);

inactivation and disposal of contaminated material.

¢Û Animal TSEs and Transmission: BSE in sheep,

differentiation of BSE from scrapie; PrPsc path from peripheral

tissues to CNS; silent carriers: (existence mechanisms and

infectivity in fluids and tissues).

¢Ü Human TSEs and risk assessment: Risk assessment of

actual human exposure to BSE (including possible regional

aspects); mathematical modeling of the human epidemic;

safety of human blood, organ transplants, therapeutics and

surgical instruments; therapeutics and prophylaxis (e.g.

preventive immunization).

Future of Japanese BSE

In Japan it clearly demonstrates the downward trend of

positive BSE cases detected over the last years, with more

than 50% reduction since 2004. Based on the improved

situation, there could be a similation to have a roadmap on

the BSE strategy in the short, medium and long-term. In

setting on strategy the greatest importance is attached to

maintaining the high level of consumer protection built up

over the years in the field of prevention, control and

eradication of TSEs. The balance of evidence is increasingly

pointing toward the need to re-consider the current priorities

in the field of food safety and animal health.

Amendment in the short and medium term (2006~

2010)

A. Special Risk Material: Assure the safe removal of

SRM but modify list/age based on new & evolving scientific

opinion. The initial list of SRM was established based on the

scientific knowledge before 1995 and the precautionally

principal. Since then, the overall situation has been improved

and new scientific data has become available. On 27-28

April 2005, the European Food Safety Authority (EFSA)

adopted on opinion on SRM supporting an increase of the

current age limit for central nervous tissue from 12 to 21 or

31 months depending on the significance given to the

extremely rare BSE cases detected in young animals. This

opinion allows us for reflection on an amendment of the

current SRM list and in particular on the age limit for the

removal.

B. Feed Ban: When certain conditions are met a relaxation

of the certain measures of current total feed ban. A ban on

the most of mammalian MBM to cattle, sheep and goat was

introduced as of September 2001 (Fig. 1). The starting point

when revising the current feed ban should be risk-based but

at the same time taking into account the control tools in

place to evaluate and ensure the proper implementation of

this feed ban. Currently there are no specific restriction with

regard to use of domestic tallow in feed (or food) to prevent

transmission of TSEs.

The restriction on the use of specified risk material is

applicable to the mandatory purification of rendered fat at

0.15% insoluble impurities according to EC regulation No.

1774/2002. A possible need for future provisions on tallow,

in particular for use in milk replacers, depends on the result

of quantitative risk assessment.

C. Surveillance programs: Continue to measure the

effectiveness of the measures in place with abattoir targeting

of the surveillance activity. The goal of surveillance is

monitoring the effectiveness of control measures such as the

feed ban and SRM removal by following the evolution of

Fig. 2. Detection of BSE prions by rapid test, Western blot (WB),

and immunohistochemistry (IHC), MAFF and MHWL are

collaborating for the surveillance and screening of BSE in Japan.

10 Takashi Onodera, Chi-Kyeong Kim

BSE prevalence. It should be noted as well that, although

active BSE monitoring is not a public health protection

measure, it has contributed to increased consumer confidence

and has played a role in the Risk Communication strategy in

Japan. In addition the surveillance results have provided

necessary data to evaluate an amendment of SRM. The

gradual increase of age limit starting for healthy slaughtered

animals and fallen stock. The increase of the age would

depend on the results of the ongoing surveillance program.

D. Cohort culling in bovine animals: Strategic goal is to

stop the immediate culling of the cohort. The cohort animals

are animals without any symptoms but they are assumed to

be at a higher risk of being infected with BSE due to an

epidemiological link. This includes animals which received

the same feed as the positive animal in the first year of their

life. Reflection on alternatives to the current destruction of

the cohort can be made. A proposed alternative would to

deter the culling and destruction at the end of the productive

life, as seen within the International OIE Animal Health

Code or to allow the slaughtered animals into the food chain

following a negative rapid testing result. Although this

relaxation would allow breeding and use of milk, the decision

to derogate from the culling should be the responsibility of

the government in order to take into account of the potential

consequences for their export markers. The derogation to

defer the culling would be the government¡¯s decision. This

relaxation would not endanger the current level of consumer

protection. A relaxation would not only reduce the economical

impact but also the social consequences following the

complete destruction of the cohorts being often one of the

main reasons to object to the culling policy. However, as the

BSE prevalence reduces, the total herd culling for destruction

may be the preferred option, in particular to trade to the

countries where BSE was absent or very rare.

Amendments in the long-term (2010~)

In case the positive trend continues, taking into account

the relaxation of the measures in the short and medium term,

further relaxation of measures can be envisaged.

A. Surveillance: The gradual decrease in the level of

surveillance can be maintained if the positive trend continues

focusing on older animals or birth cohorts from which only

limited information is available.

If only BSE cases are detected in animals above 10 years,

i.e. born before 1 January 2002, it may be decided to exclude

those animals permanently from the feed and food chain

(destruction scheme) and provide financial support for the

culling of those animals at the end of productive life. The

final surveillance strategy would be reduced to the examination

of the clinical suspect animals (if there are any) and maintenance

surveillance strategy in line with the OIE recommendations.

Special Risk Material: If BSE cases are not detected

below a certain age or drop below an agreed prevalence, the

obligation to remove the specified risk material minimal list

of SRM particularly, nervous tissues of cattle of certain age

groups, may be considered as a precautionary measure

against future epidemics or sporadic cases.

References

1. Baker HF, Ridley RM, Wells GAH. Experimental

transmission of BSE and scrapie to the common marmoset.

Vet Rec 1993, 132, 403-406.

2. Brown DA, Bruce M, Fraser JR. Comparison of the

neuropathological characteristics of bovine spongiform

encephalopathy (BSE) and variant Creutzfeldt-Jakob disease

(vCJD) in mice. Neuropathol Appl Neurobiol 2003, 29, 262-

272.

3. Brown P, Liberski PP, Wolff A, Gajdusek DC. Resistance

of scrapie to steam autoclaving after formaldehyde fixation

and limited survival after ashing at 360oC: pactical and

theoretical implications. J Inf Dis 1990, 161, 467-472.

4. Bruce M, Chree A, McConnell I, Foster J, Pearson G, Fraser

H. Tansmission of bovine spongiform encephalopathy and

scrapie to mice: strain variation and the species barrier.

Philosoph Transact Royal Soc 1994, 343, 405-411

5. Bruce M, Will RG, Ironside JW, McConnell I,

Drummond D, Suttie A, McCardle L, Chree A, Hope J,

Birkett C, Cousens S, Fraser H, Bostock CJ. Transmission

to mice indicate that ¡®new variant¡¯ CJD is caused by the BSE

agent. Nature 1997, 389, 498-501.

6. Collinge J, Palmer MS, Sidle KCL, Hill AF, Gowland I,

Meads J, Asante E, Bradley R, Doey LJ, Lantos PL.

Unaltered susceptibility to BSE in transgenic mice

expressing human prion protein. Nature 1995, 378, 779-783.

7. Cunningham AA Wells GAH, Scott AC, Kirkwood JK,

Barnett JEF. Transmissible spongiform encephalopathy in

greater kudu (Tragelaphus strepsiceros). Vet Rec 1993, 132,

68.

8. Di Martino A, Safar J, Gibbs CJ. The consistent use of

organic solvents for purification of phospholipids from brain

tissue effectively removes scrapie infectivity. Biologicals

1994, 22, 221-225.

9. Hoinville LJ, Wilesmith JW, Richards MS. An

investigation of risk-factors for case of bovine spongiform

encephalopathy born after the introduction of the feed ban.

Vet Rec 1995, 136, 312-318.

10. Hope J, Rekkie LTD, Hunter N, Multhaup G, Beyreuther

K, White H, Scott AC, Stack MJ, Dawson M, Wells GAH.

Fibrils from brains of cows with new cattle disease contain

scrapie-associated protein. Nature 1988, 336, 390-392.

11. Kirkwood JK, Wells GAH, Wilesmith JW, Cunningham

AA, Jackson SI. Spongiform encephalopathy in an Arabian

oryx (Oryx leucoryx) and a greater kudu (Tragelaphus

strepsiceros). Vet Rec 1990, 127, 418-420.

12. Kirkwood JK, Wells GAH, Cunningham AA, Jackson SI,

Scott AC, Dawson M, Wilesmith JW. Scrapie-like

encephalopathy in a greater kudu (Tragelaphus strepsiceros)

which had not been fed ruminant-derived protein. Vet Rec

BSE situation in Japan 11

1992, 130, 365-367.

13. Kirkwood JK, Cunningham AA. Epidemiological

observations on spongiform encephalopathies in captive wild

animals in the British Isles. Vet Rec 1994, 135, 296-303.

14. Onodera T, Saeki K. Japanese scrapie cases. Japan J Inf Dis

2000, 53, 56-61.

15. Peet RL, Curran JM. Spongiform encephalopathy in an

imported cheetah (Acinonyx jubatus). Aust Vet J 1992, 69,

171.

16. Scientific Steering Committee. Opinion on the Scientific

Steering Committee on the human exposure risk (HER) via

food with respect to BSE, 10th December, 1999.

17. Scientific Steering Committee. Opinion on TSE infectivity

distribution in ruminant tissues, 10-11th January, 2001.

18. Taylor DM. Scrapie agent decontamination: implications for

bovine spongiform encephalopathy. Vet Rec 1989, 124, 291-

292.

19. Taylor DM, Fraser H, McConnell I, Brown DA, Lamza

KA, Smith GRA. Decontamination studies with the agents

of bovine spongiform encephalopathy and scrapie, Arch

Virol 1994, 139, 313-326.

20.Wells G AH, Scott AC, Johnson CT, Gunnings RF,

Hanock RD, Jeffrey M, Dawson M, Bradley R. A novel

progressive encephalopathy in cattle. Vet. Rec. 1987, 121,

419-420.

21.Wijeratne W VS, Curnow RN. A study of the inheritance

of susceptibility of bovine spongiform encephalopathy. Vet

Rec 1990, 126, 5-8.

22.Wilesmith JW, Ryan JBM, Atkinson MJ. Bovine

spongiform encephalopathy: epidemiological studies on the

origin. Vet Rec 1991, 128, 199-203.

23.Wilesmith JW, Ryan JBM. Bovine spongiform encephalopathy:

recent observations on the age-specific incidences. Vet Rec

1992, 130, 491-492.

24.Wilesmith JW. Bovine spongiform encephalopathy:

epidemiological factors associated with the emergence of an

important new animal pathogen in Great Britain. Seminars in

Virol 1994, 5, 179-187.

25.Will RG, Ironside JW, Zeidler M, Cousens SN, Estibeiro

K, Alperovitch A, Poser S, Pocchiari M, Hofman A. A

new variant of Creutzfeldt-Jakob disease in the UK. Lancet

1996, 347, 921-925.

26.Willoughby K, Kelly DF, Lyon DG, Wells GAH. Spongiform

encephalopathy in a captive puma (Felis concolor). Vet Rec

1992, 131, 431-434.

http://www.vetsci.org/2006/pdf/1.pdfTSS




Follow Ups:



Post a Followup

Name:
E-mail: (optional)
Subject:

Comments:

Optional Link URL:
Link Title:
Optional Image URL: