Failure Knowledge Database / 100 Selected Cases

BSE (Bovine Spongiform Encephalopathy) / Mad Cow Disease
Sep. 21, 2001, Shiroi, Chiba
Masayuki Nakao
Institute of Engineering Innovation, School of Engineering, The University of Tokyo

A livestock cow mysteriously lost the ability to stand In Shiroi, Chiba prefecture. TheLivestock Health Station found that the pathological test revealed air pockets in the cow’s brain.
The specimen was submitted to the Veterinary Laboratories Agency in England and diagnosed
with BSE-infected. On September 21, 2001, Japan ranked the16th country confirmed with BSE
detection. The imported cattle was feed believed to be the source.
１． EventA livestock cow mysteriously lost the ability to stand In Shiroi, Chiba prefecture. The Livestock
Health Station found that the pathological test revealed air pockets in the cow’s brain. Aspecimen was submitted to the Veterinary Laboratories Agency in England and diagnosed with
BSE-infected.
２． Course
On August 6, 2001, a milk cow (Holstein, 5y 4mo) owned by a cattle farmer became incapableof standing. A brain specimen was collected at the slaughterhouse and tested at the National
Institute of Animal Health.
The prionics test, a method of diagnosing BSE, was negative when tested at the National
Institute of Animal Health on August 15.
Chiba prefecture, after the return of the negative prionics test, proceeded with further
pathological tests and detected air pockets in the microscopic image of the cow’s brain at aLivestock Health Station (Aug. 24).
On September 6, the specimen was again submitted to the National Institute of AnimalHealth.
The institution also confirmed air pockets on histopathlogical diagnosis and further tests,
immunohistochemistry (IHC), had come out positive for BSE (Sep.10).
On September 10, the Ministry of Agriculture and Forest officially announced the possibility ofBSE and set the investigative task force led by Endo Vice Minister.
By the advice of the investigative commission led by Takashi Onodera, a professor of Tokyo
University, on September 11, the specimen and domestic test results were submitted to theVeterinary Laboratories Agency in England for the final test.
The test result was received from England in the evening of September 21 and confirmed thatthe cow was infected with BSE.
Although the BSE infected cow was originally brought into the slaughterhouse, the inspector1Failure Knowledge Database / 100 Selected Cases

misdiagnosed it as septicemic disease since there were scars all over the body. Then the cow
was sent to the lettering process (making it into bone-and meat feedings) since it was notsuitable for meat processing.
After the official announcement on September 10, it dominated news headlines. Also other
BSE infected cows (5y 7mo, 5y 8mo) were found in November and December respectively.
Alarmed consumers refrained from consuming beef and severe economic losses hit the relatedindustries.
３． CauseA certain protein called an abnormal prion causes BSE. An abnormal prion transforms thenature of a normal prion that originally exists in the brain into abnormality (Fig.1). As abnormal
prions are accumulated in the brain, the brain tissue forms sponge-like spaces with fine air
pockets and causes disorders such as motor disorder. It is assumed that the cattle feed in thiscase has contained the infected bone-and-meat feed which carry abnormal prions and caused
BSE. Although the bone-and-meat feed that was made from the cow infected by abnormal
prions also contained abnormal prions, the infection route has not clearly identified yet.

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Fig.1 abnormal prion growth (model) [1]４．Immediate Action
After receiving the test result from the National Institute of Animal Health, the Ministry ofAgriculture and Forest, on September 10, officially announced the possibility of BSE.
Government officials immediately ordered a quarantine of the cow and initiated anenvironmental epidemiologic investigation on this matter including the background of the cowand a description of the cattle feed.
On the same day, the Ministry of Health, Labor and Welfare took the precaution of suspending
the sales of beef until the diagnosis was confirmed. The government officials also decided tohold a study group meeting of “Research on BSE” led by Morikazu Shinagawa, a professor ofObihiro University of Agriculture and Veterinary.

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On September 19, a screening test was introduced at national Meat Sanitary Inspection
Stations (117 stations). Further testing was performed on suspected cows and the study groupconfirmed the diagnosis.
The Subjected cows had the following findings;① Within the age group of 24 month and older, those presenting symptoms of motor disorder,
perceptual disorder, neurological dysfunction such as abnormal reflexes or consciousness,
and absence of systemic symptoms (the test was already implemented at the site of theinitial occurrence).
② The group of cattle 30 months and older including those who do not present anydysfunctions.
Also the media broadcast scenes that Takebe, Minister of Agriculture, Forestry and Fisheries
or Sakaguchi, Minister of Health, Labor and Welfare consuming beef on TV to cast asideconsumer’s safety concerns.
５． Countermeasure
A new law banned providing cattle with bone-and-meat feed with a penalty, to avoid spreading
BSE.
The Government also suspended all imports and domestic production and distribution ofbone-and-meat feed. These measures were as good as those in England but did not last long.
Although distribution of bone-and-meat feed was stopped at once, related businesses werestrongly against total prohibition. In addition, there were not enough incineration and repository
facilities; suspension was rescinded on only cattle within a month.
To avoid human transmission, a BSE test became mandatory on all beef cattle. Although there
was no clear scientific indication that cows under 30 months old need to be tested, there was nocensus registration system on cattle, and erring on the side of safety was thought to be the mostimportant issue.
Moreover, high-risk meat speciation such as brain or spinal marrow was banned for
consumption while the processing method of beef cattle was re-examined. The government
incinerated those high-risk meat speciation produced at slaughterhouses, and recalled medical
supplies and food that contain those meat speciation.
６．Summary
In September 2001, Japan was the 16th country that confirmed detection of BSE. It was thefirst case in Asia other than Eastern and Western Europe. It is important to find out why the cattle
disease which had occurred only in England and Europe has landed in Japan where human andeconomic bonds are much weaker than those with the US or Australia. Although there are still
many unsolved mysteries regarding BSE, the affected countries have already establishedmeasures to block the spread and transmission to humans. By contrast, not enough measures
were taken in Japan until this suspected case occurred in September 2001.
After discovery of three BSE infected cows, four more cases were found in May 2002 (6y 14

Failure Knowledge Database / 100 Selected Casesmo), in August 2002(6y 8mo), in January 2003 (6y 11mo, 6y 9mo), a total of seven cows thatwere in an age group of five to six years old. The incubation period for BSD is believed to be
between two to eight years after infection. However, prions were found in young cows (1y 11mo,1y 9mo) in October 2003 and furthermore the structure of this protein agent was different fromthe original one, which reversed the original thought that there was a single kind of BSE (two ofthe same cases each were also reported in Italy and France). This discovery was due toperforming mandatory testing on every cow, regardless of their age. It would be a chilling
revelation if the original plan to limit the screening tests to cows 30 months and older wasgranted. The mystery of BSE regarding such as infectability or its source deepens more andmore.
７．Acquaintance
Effective measures are usually not taken until an incident actually happens. People’s
perception of “fire on the other side of the river” will not be easily mended even though the world
has become globalized.
Also the business world often tends to care about profits before safety so that consumers
need to have their own means (opting to not eat beef in this case).
In the meantime the view that “guilty until proven innocent” is indispensable for our own
protection. A new type of abnormal prion was found by testing all beef cattle regardless of theirage.
８．Background
BSE was originally found in England in 1986. After the investigation of this case, Englandbanned the use of bone-and-meat feed which was known to be the source of BSE. However,even cows that were born after the banning and were not supposed to have eaten any of thebone-and-meat feed were infected with BSE. The theory that cattle feed had been contaminatedby that for pigs or chickens was highly suspected and the use of bone-and-meat feed wascompletely banned for any livestock feed in 1996. Even so, England experienced a serious
outbreak of BSE, which peaked in 1992 at 36,682 infected cows and recorded a total of about
170,000 cases between 1990 and 2000.
The risk of bone-and-meat feed was reported from Meldrum, British CVO (Chief VeterinaryOfficer) of the OIE (Office International des Epizooties) in May 1989. Also a letter dated
February 14, 1990 was sent to every CVO in the countries that import bone-and-meat feed(including Japan). (Fig1).
Regarding human transmission of BSE, in the village of Queniborough in England, threepeople in 1998 and two people in 2000 had sudden denaturation in their brain nerve cells,caused by abnormal prions and subsequently died from a new variant of Creutzfeldt-Jakob
Disease (CJD), where the brain sometimes becomes like a sponge. These people were exposedto cows infected with BSE in common (March 21, 2001). There is another infectious disease ofsheep called “Scrapie” caused by a prion other than bovine BSE; it had not appeared to betransmissible to humans before.

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Figure 1 a letter sent to CVO of countries England exports their bone-and-meat feeding [1]９．On the side
Before the first case of BSE was reported in Japan in August 2001, the EU, in 1990, firstwarned the Ministry of Agriculture and Forestry that their methods of prevention against BSE
were not sufficient. The officials quickly requested the EU to withdraw their exhortation.
Awareness of the fact that governmental institutions become autotelic once they become
entrenched; and that makes them incapable of taking precautions from making mistakes.
Although the Agricultural Ministry reviewed their previous actions and launched a BSE researchcommittee afterwards, there were no clear statements for improvement even in the report
finalized in April 2002.

<References>[1]

NHK “BSE” research crews, written by Toshihide Yabuki: face up to “BSE” published byNHK (2002)[2] Ministry of Health, Labor and Welfare web page: http://www.mhlw.go.jp/[3]

Nihon Keizai Shimbun dated November 16, 2003: Mysteries of a new variant of BSE6