A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: 16 Apr 2009
Source: CFIA Press Release [edited]
Click on title above to see report:
Report on the Investigation of the 14th Case of BSE in Canada
--------------------------------------------------------------
On 25 Jul 2008 a commercial beef cow in Northern Alberta was sampled
by a private practitioner under Canada's National BSE Surveillance
Program. Brain samples from this animal were sent to the Alberta
Agriculture and Rural Development (ARD) laboratory where they were
screened for bovine spongiform encephalopathy (BSE) using a Bio-Rad
rapid test on 6 Aug 2008. The result of this preliminary test did not
rule out BSE. In accordance with the prescribed testing protocol, the
test was repeated and produced a reaction a 2nd time. Brain samples
were then sent to the National BSE Reference Laboratory in
Lethbridge, Alberta. Additional rapid tests for BSE (Prionics-Check
PrioStrip and BioRad TeSeE ELISA) were conducted at the National BSE
Reference Laboratory to validate the result of the screening test and
were positive on 12 Aug 2008. The Prionics-Check Western and the
Hybrid Western Blot was positive on 14 Aug 2008. BSE was confirmed on
14 Aug 2008 using the Scrapie Associated Fibril Immunoblot procedure.
The carcass was secured at the sampling site. No part of the carcass
entered the human food supply or animal feed chain.
The CFIA immediately initiated an epidemiological investigation based
on the recommended BSE guidelines (Terrestrial Animal Health Code
2008) of the World Organisation for Animal Health, referred to as the
OIE. Specifically, the CFIA followed the recommended BSE guidelines
for a country with controlled risk status and investigated:
* the feed cohort, comprising all cattle which, during their 1st
year of life, were reared with the BSE case during its 1st year of
life, and which investigation showed consumed the same potentially
contaminated feed during that period, or
* the birth cohort, comprising all cattle born in the same herd as,
and within 12 months of the birth of the BSE case, if the above
cannot be identified and
* feed to which the animal may have been exposed early in its life.
[Members should read the full script. The 2 key paragraphs read as
follows. - Mod.MHJ]
Neither of the 2 commercial feed manufacturers has production records
dating back to the period of interest. As a result, trace back
inspections at the manufacturers of commercial feeds distributed to
the birth farm did not yield mixing formulas for the period of
interest. As this was subsequent to the implementation of the 1997
Mammalian Feed Ban, it is very unlikely that ruminant meat and bone
meal was intentionally used in the formulation of any of the 3
commercially prepared rations or loose mineral salt distributed to
the birth farm.
However, as production records are not available for review, it is
not possible to rule out that contamination during production could
have taken place. One of the 2 commercial feed manufacturers did
handle ruminant meat and bone meal (prohibited material/PM), however
they did have procedures in place to prevent the contamination of
ruminant feed with PM. The other commercial feed manufacturer did not
handle PM directly, though they did receive a premix used in the
manufacture of one of the feeds received by the case farm, from
another facility which did handle PM.
--
Communicated by:
ProMED-mail
******
[2]
Date: 16 Apr 2009
Source: CFIA Press Release [edited]
Report on the Investigation of the 15th Case of BSE in Canada
-------------------------------------------------------------
On 3 Nov 2008, the Canadian Food Inspection Agency (CFIA) sampled a
Holstein cow under Canada's National BSE Surveillance Program. Brain
samples were received by the British Columbia Ministry of Agriculture
and Lands (BCMAL) Laboratory, where they were screened for bovine
spongiform encephalopathy (BSE) using a Prionics rapid test. The
result of this preliminary test did not rule out BSE. In accordance
with the prescribed testing protocol, the test was repeated and
produced a reaction a 2nd time. Brain samples were then sent to the
National BSE Reference Laboratory in Lethbridge, Alberta. Additional
testing for BSE (Prionics-Check PrioStrip, BioRad TeSeE ELISA,
Prionics-Check Western and Hybrid Western Blot) was conducted at the
National BSE Reference Laboratory to validate the result of the
screening test and was positive on 6 Nov 2008. The Scrapie Associated
Fibril Immunoblot procedure was positive on 7 Nov 2008 and the
immunohistochemistry procedure was positive on 14 Nov 2008. The
carcass was secured at the sampling site and will subsequently be
transferred to CFIA's Lethbridge laboratory for incineration. No part
of the carcass entered the human food supply or animal feed chain.
[Members are encouraged to read the full report. However the key
paragraph reads as follows. - Mod.MHJ]
Considering the farm's feeding regime and specific production records
reviewed, a likely source of exposure to BSE infectivity appears to
be potentially contaminated heifer ration. However, the risk
associated with possible ingestion of small amounts of the lactation
ration and either of the mineral blocks exists, and potential
contamination of these products cannot be ruled out.
--
Communicated by:
ProMED-mail
[As usual the Canadian Food Inspection Agency has done an outstanding
job in investigating these events and with full transparency. - Mod.MHJ]
[See also:
BSE, bovine - Canada (04): (BC) 20081119.3648
BSE, bovine - Canada (03): (AB) 20080819.2580]
..................................mhj/ejp/mpp
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