##################### Bovine Spongiform Encephalopathy #####################
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: [email protected]
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
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http://www.vetsci.org/2006/pdf/1.pdfTSS
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now, before anyone complains about this long post (unless it's the one paying for it, i will comply with anything there), the reason i do this is some don't have pdf capabilities (well, less now than use to be), and if anyone plans to debate the topic and or the contents there of, it's much easier having accessed it here, to reference to, than everyone having to register, and go back and forth from here to there, and or sometimes some of these important files do not stay on the www. i hope that might help explain why i post some of these long threads. and if it is problem, i can stop. simple as that. .......kind regards, terry
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: [email protected]
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.
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http://www.vetsci.org/2006/pdf/1.pdfTSS
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now, before anyone complains about this long post (unless it's the one paying for it, i will comply with anything there), the reason i do this is some don't have pdf capabilities (well, less now than use to be), and if anyone plans to debate the topic and or the contents there of, it's much easier having accessed it here, to reference to, than everyone having to register, and go back and forth from here to there, and or sometimes some of these important files do not stay on the www. i hope that might help explain why i post some of these long threads. and if it is problem, i can stop. simple as that. .......kind regards, terry
