An Estimate of the Prevalence of BSE in the United States
Prepared by
Centers for Epidemiology and Animal Health
National Surveillance Unit
April 27, 2006
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Executive Summary
The United States has conducted bovine spongiform encephalopathy (BSE) surveillance
with increasing intensity since 1990, including an enhanced effort following the
identification of a Canadian cow that tested positive in 2003 (APHIS 2006). The goal of
this analysis is to estimate the prevalence of BSE in the United States using surveillance
data that have been collected over the 7-year period prior to March 17, 2006; this
surveillance timeframe reflects World Organization for Animal Health (OIE) guidelines,
which suggest determining prevalence over a 7-year period. This information will help
guide and support future requests for consideration of the overall BSE status of the
United States. This report is considered a draft and will undergo peer review. Moreover,
in the interest of transparency, this information will also be made publicly available on
the U.S. Department of Agriculture website.
Among the 735,213 cattle sampled in the 7 years prior to March 17, 2006, two infected
indigenous animals were identified by the surveillance in addition to the 2003 imported
cow from Canada. The results of this analysis suggest that the number of infected cattle
in the United States is very low.
We estimated the prevalence using two methods. The first estimate is from the BSurvE
model (Wilesmith et al., 2004) and is based only on surveillance testing data with no
additional information about an effective feed ban. The second method, the Bayesian
Birth Cohort model (BBC), was suggested by Vose Consulting in an independent review
of the analysis1 and uses the point assignments (sample's information value) from the
BSurvE model. It assumes that the U.S. feed ban implemented in 1997 was at least as
effective as a feed ban initiated by the United Kingdom (UK) in 1988 and that prevalence
in the United States would decline proportionately. The mathematical techniques used in
this method combine the surrogate UK feed ban effectiveness with U.S. surveillance data
to provide a more precise estimation of the expected prevalence in the United States.
The most likely value (with upper and lower confidence levels) for the estimated number
of BSE infected cattle from the two models was 4(1 , (BBC) and 7(3 , 24) (BSurvE) in
a population of approximately 42 million adult cattle. The results, including upper
bounds of both methods, support a conclusion that the prevalence of BSE in the United
States is less than 1 infected animal per million adults.
The data were re-analyzed to determine the sensitivity of the prevalence estimate to:
1. The BSurvE algorithm and its assumptions,
2. Inclusion of additional cases (for example, the Canadian origin animal) with the
same amount of negative surveillance, and
3. Alternatives for assumptions and input parameters to the BSurvE model.
In each case, the magnitude of change due to the uncertain parameters was not substantial
and did not change the conclusion that the prevalence of BSE is less than 1 BSE infected
animal per million adult cattle. The upper and lower bounds from these analyses were 1
to 30 infected animals. Further, when as many as 5 BSE cases (2 indigenous and 3
hypothetical) were included in the surveillance data but no additional negatives, the
conclusion remained robust with an upper bound (95th percentile) of 40.
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Introduction ... snip ... END
SEE FULL TEXT 43 PAGES ;
http://www.aphis.usda.gov/newsroom/hot_ ... -26-06.pdf
i would take this with a grain of salt. just like the original Harvard BSE risk assessment that was so terribly flawed. check out the peer review of the original Harvard risk assessment. then add to that all the OIG and GAO reports trying to keep them in line, and you have another biased i.e. 'loaded' assessment,
to say the least, and when i say loaded, it's loaded in their favor i.e. minimal guesstimate of home grown BSE/BASE/? cases. i find it amazing the USA has
some kind of mad cow resistant bovines, and that they are simply not finding any, after those two h-BASE atypical BSE cases were found in Texas and Alabama,
and this after leaving the suspect mad cow samples to sit on a shelf for 7+ plus months all the while certifying GWs and the OIE BSE MRR policy. daaa. then to think of the stumbling and staggering mad cow suspect that they did manage to cover up in Texas, the credibility of the USDA et al is as about as near nothing as it gets. ...tss
[Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine
Spongiform Encephalopathy (BSE)
MY comments/questions are as follows ;
1. SINCE the first Harvard BSE Risk Assessment was so flawed and fraught with error after the PEER REVIEW
assessment assessed this fact, how do you plan on stopping this from happening again, will there be another peer
review with top TSE Scientist, an impartial jury so-to-speak, to assess this new and updated Harvard BSE/TSE risk
assessment and will this assessment include the Atypical TSE and SRM issues ?
*** Suppressed peer review of Harvard study October 31, 2002 ***
http://www.fsis.usda.gov/oa/topics/BSE_Peer_Review.pdf
http://www.fsis.usda.gov/OPPDE/Comments ... 0011-1.pdf
SEE FAILURES ;
Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle
Still Remain Our prior report identified a number of inherent problems in
identifying and testing high-risk cattle. We reported that the challenges in
identifying the universe of high-risk cattle, as well as the need to design
procedures to obtain an appropriate representation of samples, was critical
to the success of the BSE surveillance program.
http://www.usda.gov/oig/webdocs/50601-10-KC.pdf
[GAO-05-101 ] Mad Cow Disease: FDA's Management of the Feed Ban Has Improved, but Oversight Weaknesses
Continue to Limit Program Effectiveness
Size: 104986 , Score: 1000 , TEXT , PDF , SUMMARY
http://frwebgate.access.gpo.gov/cgi-bin ... s/data/gao
January 2002
MAD COW DISEASE Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts
http://www.gao.gov/new.items/d02183.pdf
February 2005
MAD COW DISEASE
FDA's Management of the Feed Ban Has
Improved, but Oversight Weaknesses
Continue to Limit Program Effectiveness
http://www.gao.gov/highlights/d05101high.pdf
http://www.gao.gov/new.items/d05101.pdf
Tuesday, January 1, 2008
BSE OIE USDA
http://madcowtesting.blogspot.com/2008/ ... -usda.html
BSE BASE MAD COW TESTING TEXAS, USA, AND CANADA
http://madcowtesting.blogspot.com/
TSS
