LEAD: Latest mad cow case in Japan resembles Italy cases

Japan Policy & Politics, Oct 14, 2003

TOKYO, Oct. 12 Kyodo

(EDS: RECASTING WITH ONODERA'S REMARKS)

A cow in Ibaraki Prefecture confirmed as Japan's eighth and latest case of mad cow disease has exhibited a very similar prion structure to that found in two BSE cases in Italy, a Japanese expert said Sunday, referring to recently announced Italian research.

With the agriculture ministry trying to trace the source of infection for the latest case, Takashi Onodera, professor at the University of Tokyo, raised the possibility that an infected cow in Italy became the source for the case.

''It is possible that an infected cow in Italy was imported into the country as meat-and-bone meal (MBM) and became the source of infection for the eighth case,'' said Onodera, who heads a government study panel on mad cow disease, which is formally known as bovine spongiform encephalopathy (BSE).

He added that he intends to study with Italian experts the prions that link the three cows.

Reported at a recently held international conference on prion diseases in Germany, the Italian findings provide invaluable information, given that there are no other cases in the world involving cows with such a similar prion structure.

Acting on this research, the Agriculture, Forestry and Fisheries Ministry will soon call in Onodera, who attended the conference, to brief the ministry about the research.

The ministry will then decide on the next steps to take regarding the latest case of mad cow disease.

BSE is believed to be caused by the consumption of MBM contaminated with prions -- protein particles lacking nucleic acid that have been linked to nervous system illnesses such as Creutzfeldt-Jakob disease.

Onodera said the Italian research showed that two cows aged 11 and 12 exhibited a different prion structure and different pathological changes in their brains, where prions concentrate, to other cows involved in the mass BSE outbreak that occurred throughout Europe.

Japan's latest BSE case -- a 23-month-old Holstein cow infected with an atypical form of BSE -- revealed an almost identical prion structure to that found in the cows in Italy. But the cow here did not share the other characteristic relating to the pathology of the brain.

On the seven other cattle earlier diagnosed with BSE in Japan, the ministry put the probable source of the BSE outbreak as either cows imported from Britain in the 1980s or contaminated MBM imported from Italy before 1990.

The ministry said it is possible that there is a different route of infection in the latest case, since the cow was born at a different time to the seven other cattle.

The cow is younger than the others, and it is rare for a cow under 24 months to be diagnosed with the disease.

Japan reported its first BSE case in September 2001 in Chiba Prefecture.