BSE UPDATE ALABAMA March 17, 2006
MONTGOMERY - Alabama Agriculture & Industries Commissioner Ron Sparks, State Veterinarian Dr. Tony Frazier, and Dr. Ken Angel with the USDA held a press conference today to answer questions about yesterday's exhumation of the remains of the cow that tested positive for BSE.
Federal and state agriculture workers excavated the remains of the animal, which had been buried on the farm and did not enter the animal or human food chain, in accordance with USDA protocols. The carcass was that of a red crossbred beef type cow. An examination of the cow's teeth confirmed that the animal was at least 10 years of age. Samples were taken of the animal and the remaining carcass was transported to one of the department's diagnostic labs for proper disposal. State and Federal staff are continuing the traceback to determine the herd of origin.
One calf was identified by the owner as belonging to the red cow. The calf is approximately 6 weeks old and appeared to be a healthy animal. The calf was transported to a USDA lab where DNA from the calf will be compared to that of the red cow to confirm relation. If confirmed, this would be the first offspring of a BSE diagnosed cow in the United States. Officials today learned that in early 2005 the BSE-positive cow gave birth to another black bull calf. This animal is in the process of being traced.
The cow was first examined by a local veterinarian in late February 2006. After the animal failed to respond to medical attention, it was humanely euthanized. The cattle producer buried the cow at the farm because Alabama Department of Agriculture & Industries regulations require burial of livestock within 24 hours. The producer did not suspect that the cow had BSE. The local veterinarian sent samples of the cow to the Alabama Department of Agriculture & Industries lab
system, which was then forwarded to the USDA lab in Athens, GA as part of the routine voluntary surveillance program for BSE testing. After the rapid test for BSE gave an inconclusive result, the samples were sent to Ames, Iowa for a Western Blot test, which gave a positive result. A third test, the immunohistochemistry (IHC) test, was performed this week and also returned positive results for BSE.
The Alabama Department of Agriculture and Industries and the USDA have been encouraging participation in Premises ID Registration as an important step in controlling animal disease. Since starting the program in 2005, over 2,000 premises have been registered in Alabama. For more information on Premises ID Registration call 334-240-7253
http://www.agi.state.al.us/press_releases/bse-update
http://www.agi.state.al.us/press_releases/bse-update?pn=2
ITEM 6 – BARB CASE CLUSTERS
39. Professor John Wilesmith (Defra) updated the committee on the
BSE cases born after the 1996 reinforced mammalian meat and
bone meal ban in the UK (BARB cases). Around 116 BARB cases
had been identified in Great Britain up to 22 November 2005,
mostly through active surveillance. BARB cases had decreased in
successive birth cohorts, from 44 in the 1996/1997 cohort to none
to date in the 2000/2001 cohort. However, 3 BARB cases had
been identified in the 2001/2002 cohort. Backcalculation of the
prevalence of BARB cases indicated a drop from 130 infected
animals per million (95% confidence interval 90-190) in the
1996/1997 cohort to 30 infected animals per million (95%
confidence interval 10-60) in the 1999/2000 cohort. A shift in the
geographical distribution of BSE cases, from the concentration of
pre-1996 BSE cases in Eastern England to a more uniform
14
© SEAC 2005
distribution of BARB cases, had occurred. However, it appeared
that certain post-1996 cohorts had a higher exposure to BSE in
certain areas for limited periods. Several clusters of BARB cases
within herds had been identified (5 pairs, 2 triplets and 1
quadruplet).
40. A triplet of BARB cases in South West Wales had been
investigated in detail. The triplet comprised 2 cases born in
September and October 2001 and a third in May 2002. The
animals born in 2001 were reared outdoors from the spring of 2002
but the animal born in 2002 had been reared indoors. Further
investigation of feeding practices revealed that a new feed bin for
the adult dairy herd had been installed in September 1998. In July
2002 the feed bin was emptied, but not cleaned, and relocated. All
3 BARB cases received feed from the relocated bin. This finding
suggested the hypothesis that the feed bin installed in September
1998 was filled initially with contaminated feed, that remnants of
this feed fell to the bottom of the bin during its relocation, and thus
young animals in the 2001/2002 birth cohort were exposed to
feedstuffs produced in 1998. No adult cattle had been infected
because of the reduced susceptibility to BSE with increasing age.
41. Further investigation of multiple case herds had found no
association of BARB clusters with the closure of feed mills.
42. Professor Wilesmith concluded that there is evidence of a decline
in risk of infection for successive birth cohorts of cattle. The BARB
epidemic is unlikely to be sustained by animals born after 31 July
2000. Feed bins could represent a continued source of occasional
infection and advice to farmers is being formulated to reduce this
risk. There is no evidence for an indigenous source of infection for
the BARB cases.
43. Members considered it encouraging that no other factor, apart from
feed contamination, had been identified as a possible cause of
BARB cases to date. Members commented that this study
suggests that only a small amount of contaminated feed may be
required for infection and that BSE infectivity can survive in the
environment for several years. Professor Wilesmith agreed and
noted that infection caused by small doses of infectious material
was consistent with other studies, and it would appear there is little
dilution of infectivity, if present, in the rendering system.
Additionally it appeared that the infectious agent had survived for 4
years in the feed bin.
44. The Chair thanked Professor Wilesmith for his presentation.
snip...
http://www.seac.gov.uk/minutes/final90.pdf
TSS