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From: TSS (216-119-143-162.ipset23.wt.net)
Subject: BSE has been diagnosed in a cow born in April 2000
Date: August 8, 2004 at 6:30 pm PST
-------- Original Message --------
Subject: BSE has been diagnosed in a cow born in April 2000
Date: Sun, 08 Aug 2004 20:28:58 -0500
From: "Terry S. Singeltary Sr."
To: Bovine Spongiform Encephalopathy
© Defra 2004
A BSE case born in April 2000
BSE has been diagnosed in a Limousin Cross cow, born on 01 April
2000, forty-four months after 1 August 1996, when extra control
measures on animal feed containing mammalian meat and bone meal
(MMBM) were considered to have been fully implemented. The animal
was taken under passive surveillance as a clinical suspect. Its farm of
origin was in Derbyshire, where it remained until it was slaughtered as a
BSE suspect on 25 June 2004. Disease was officially confirmed on 04
August 2004.
This is the most recently born case of BSE confirmed in the UK. It was
always expected that a small number of cases would be born after the
feed ban, and the appearance of these cases is in no way unexpected.
http://www.defra.gov.uk/animalh/bse/animal-health/010400.pdf
© Defra 2003 Page 1 of 3
BSE Cases Born on or After 1 August 1996: Q & A
Q. What is significant about the date 1 August 1996?
A. Since BSE was first recognised, controls on animal feed have been central
to the UKs eradication policy. It is believed that most infected cattle
were
primarily exposed to the BSE agent through feed containing meat and bone
meal
(MBM) produced by the rendering of ruminant material. Since 1988, extensive
regulatory controls have been introduced by the Government and the EU
to keep potentially infectious material out of ruminant feed, with the
aim of
removing exposure to BSE. In 1996, controls were extended to prevent the
feeding of mammalian MBM to all farmed livestock, in order to avoid any
possibility of cross-contamination with feed for pigs and poultry. Since
1 August
1996 it has been an offence to possess mammalian MBM on premises where
livestock feed is used, produced, prepared or stored.
Q. What are the possible causes of BSE cases in cattle born after 1 August
1996?
A. Scientific advice suggests that the following routes of transmission
might be
theoretically possible:
(a) some animals might have been exposed to BSE through feed
carried over from before 1 August 1996 (either accidentally or
deliberately); or
(b) some animals might have been exposed to BSE through maternal
transmission; or
(c) there may be routes of transmission which have not yet been
identified. Possibilities include environmental contamination,
contamination of imported feed ingredients and the use of tallow-based
calf milk replacer; and/or
(d) the disease may occur spontaneously in a small number of cases.
© Defra 2003 Page 2 of 3
Q. What are the implications if further post-August 1996 cases continue
to appear?
A. The latest opinion of the EU Scientific Steering Committee, adopted
on 10-11
April 2003, effectively removed its previous threshold for concern of 55
of these
cases during a 12 month period. This figure was derived some time ago and
assumes that 10% of such cases would be due to maternal transmission. The
SSC concluded that: These model-based estimates have been overtaken by two
sources of subsequent intelligence , i.e. the results of the
Community-wide active
surveillance programme and the fact that the majority of BARB cases are
unlikely
to have been caused by maternal transmission. There is likely to be a small
increase in case numbers as animals born in 1996 and 1997 reach the
peak-risk
age for clinical BSE and animals from the 1998/1999 and 1999/2000 cohorts
may be expected to contribute more cases.
Q. What are the human health implications of these cases?
A. There are no public health implications arising from these cases.
Even if the
animals involved had not been suffering from BSE, because they have all been
over thirty months old they would have been excluded from human or animal
consumption. Any surviving offspring born after August 1996 are traced and
excluded from human consumption too.
Q. What if the over thirty months rule is scrapped?
A. All over thirty month cattle would need to be tested for BSE before
they could
enter the food chain. Any cows that tested positive for BSE would be
destroyed.
The BSE test was rigorously checked before it came into use. No incorrect
results were found. More than 20 million cattle have now been tested
throughout
the European Union. In the UK, more than 600,000 cattle have been tested.
Q. Has the Department investigated the cause of individual post-August
1996 animals?
A. All such cases are the subject of detailed veterinary enquiries.
Although it is
very difficult to show how individual animals contracted BSE, veterinary
advisers
see no indication that maternal transmission could explain the majority
of these
cases either the dams are still alive and healthy, or they were
slaughtered
without exhibiting signs of BSE long after the birth of the affected
progeny.
Similarly, whilst exposure from an environmental source cannot be
eliminated, it
would appear unlikely based on the results of enquiries into the cause of
individual cases and in the absence of other BSE cases on a number of the
affected farms. The evidence thus seems to point to a feed-borne source
as the
most likely explanation for the BARB cases.
© Defra 2003 Page 3 of 3
Q. So, are there major problems with the UK feed ban?
A. Domestic feed controls are enforced by a major sampling programme under
which around 16-18,000 samples are taken each year from different premises.
The results of the sampling programme indicate a high level of
compliance with
the feed ban. In 2003, EU scientists have also indicated that there are
so far no
reasons to assume widespread and systematic inappropriate implementation of
the current feed ban of 1996 .
Q. What else is the Government doing to follow up these cases?
A. Epidemiological investigations will continue in all cases and a
specific study is
being planned to investigate the possible reasons for the occurrence of
these
cases. In addition, the cohorts of the affected animals (animals born 12
months
before and after the index case and which may have been exposed to the same
source of infection) are identified. When these animals are slaughtered,
brain
samples are taken to see if they have also been affected. These cohort
animals
are also excluded from human consumption but they are not slaughtered
immediately. Monitoring their progress allows them to develop signs of
disease,
and ensure that important epidemiological evidence is not destroyed.
Q. What tests are used to diagnose BSE cases?
Descriptions of the tests used to diagnose BSE are available on the DEFRA
website under Science/Research into BSE/Diagnosis of BSE.
Q. Does the appearance of post-August 1996 cases mean that the
epidemic is not declining as predicted?
A. No. The overall BSE epidemic in Great Britain continues to decline by
around
40 per cent a year. In 1992, approximately 37,000 clinical cases were
detected.
Last year there were just over 1,000.
Q. Have other EU member states experienced BSE cases in young
animals (i.e. born since 1 August 1996)?
A. Yes. Most EU member states have recorded cases born after this date.
The highest numbers have been recorded in France, Germany, Portugal and
Spain. It should be noted, however, that these countries have carried
out more
active surveillance than the UK over time, because they are required to
test all
cattle over 30 months old which are sold for human consumption. At
present, the
UK tests only cattle aged more than 42 months and born after August
1996, plus
a sample of 10,000 older cattle slaughtered under our Over 30 Months Scheme.
In addition, a fully effective feed ban in the EU was not put in place
until January
2001.
Details on the numbers of cases and their dates of birth are available
on the
Office International des Epizooties (OIE) website and on individual
countries
websites accessed via the OIE website. http://www.defra.gov.uk/animalh/bse/animal-health/barbq%2Ba.pdf TSS
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