THIS week, Britain鈥檚 official inquiry into the BSE epidemic releases its
verdict. But as Britain analyses its mistakes, France may be repeating them.
While there has been a dramatic increase in French BSE cases reported this
year, tests on cattle show the true number may be far higher. Meanwhile, up to
five people in France have already succumbed to vCJD, the human form of BSE.
So far this year, France has had 48 confirmed cases of mad cow disease. But
last year the European Union told member states to test for BSE in cattle not
visibly ill with the disease, to see how much unsuspected infection might be
circulating.
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France has started testing high-risk cattle found dead or destroyed for other
reasons. 鈥淏ecause of the low number of clinical cases, they expected to find
only one or two infected in 40,000 tests,鈥� says Markus Moser of Prionics, the
Zurich-based company that makes the prion test that France is using. Instead, 25
of the first 15,000 tested harboured BSE. This means that the total number of
high-risk cattle carrying BSE could be six times the number of cases reported
this year.
In contrast, when Switzerland tested all such high-risk cattle last year, it
discovered the same number were carrying BSE as had been reported sick with the
disease that year
(麻豆传媒, 4 December 1999, p 11).
The initial results from the tests suggest that BSE infection is more
widespread in French cows than official numbers indicate, suggesting massive
under-reporting of cases. The number of reported BSE cases in France has risen
steadily since 1997, when six were reported. Moser thinks this increase in
French cases is large enough to reflect a real spread of the disease. He fears
that farmers may start taking sick cattle to market instead of risking them
dying and being tested for BSE, as a positive test means the whole herd must be
destroyed. This would expose people to more infection.
A study by the European Commission this year concluded that infection can
still spread in French cattle, although farmers are not allowed to feed them
bovine meat and bonemeal. Pigs can eat these, and bovine material intended for
pigs may contaminate cattle feed in mills.
French officials are now tightening their controls on beef destined for human
consumption. This month they have banned the use of bovine intestine, which can
carry BSE, for human consumption. France already has three confirmed cases of
vCJD, and two more are considered probable.