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Bovine spongiform encephalopathy (BSE)

Last update date March 27, 2019

What kind of disease is BSE?

BSE (Bovine Spongiform Encephalopathy) is disease of beef called bovine spongiform encephalopathy. We were confirmed for the first time in the U.K. in 1986.
Because brain of beef which hung over BSE vacuolised and became spongy (spongiform), it was named bovine spongiform encephalopathy.
It is thought that this disease is caused by kind of protein called "prion" smaller than virus. Originally animal has normal prion protein, but it is "abnormal prion protein" that causes disease. When abnormal prion protein enters the body of beef, we change normal prion protein into abnormal prion protein in sequence. When abnormality prion protein which changed collects to brain and nerve, vacuole occurs to brain and nerve and, after latency period of 2-8 years (normal 2-5 years), becomes sick and comes to show action abnormality, failure of muscular coordination. It may be called mad cow disease from the symptom, but we did not express the condition of a patient of BSE exactly, and this is not appropriate. Cow results in death after the attack in six months from two weeks.


Reason why BSE spread through

We have not understood that it has a lot on outbreak of BSE yet.
Meat-and-bone meal processed the internal organs, skin, bone which remained which took meat out of beef and was made, and it was used as manure and bait of domestic animal. It is thought that we became cause that it opens infection of BSE that beef which hung over BSE was mixed in materials of this meat-and-bone meal. In this way, BSE infects by eating abnormality prion protein which is pathogen, but may not move through contact and air between beef.

It is confirmed abnormal prion protein concentrates on some parts including tonsils of beef which hung over BSE and ileal distal part, and to be included. Therefore these parts are considered to be specific part by law and become a target to be eliminated.
Specific part

  • *momo of all age of the month, ileal distal part
  • The head (except tongue, jowl, skin, tonsils), spinal cord which are more than age for 30 months

BSE related information

Examination of Yokohama-shi meat hygiene place homepage
Ministry of Health, Labour and Welfare homepage (the outside site)
Ministry of Agriculture, Forestry and Fisheries homepage (the outside site)

Inquiry to this page

Health and Social Welfare Bureau health security department food board of health

Telephone: 045-671-2460

Telephone: 045-671-2460

Fax: 045-550-3587

E-Mail address [email protected]

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