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Volume 12, Number 12—December 2006
Perspective

On the Question of Sporadic or Atypical Bovine Spongiform Encephalopathy and Creutzfeldt-Jakob Disease

Paul Brown*Comments to Author , Lisa M. McShane†, Gianluigi Zanusso‡, and Linda Detwiler§
Author affiliations: *Bethesda, Maryland, USA; †National Institutes of Health, Bethesda, Maryland, USA; ‡University of Verona, Verona, Italy,; §Virginia-Maryland Regional College of Veterinary Medicine, College Park, Maryland, USA

Main Article

Table 1

Total number of older cattle with negative test results required to achieve 95% or 99% confidence* that sporadic cases of BSE are not present at a level higher than the illustrated prevalence rates†

Maximum prevalence Log10 prevalence No. tested cattle
95% Confidence 99% Confidence
1 per million –6.000 2,995,731 4,605,168
1 per 2 million –6.301 5,991,463 9,210,338
1 per 3 million –6.477 8,987,195 13,815,508
1 per 4 million –6.602 11,982,928 18,420,678
1 per 5 million –6.699 14,978,660 23,025,849
1 per 6 million –6.778 17,974,392 27,631,019
1 per 7 million –6.845 20,970,124 32,236,189
1 per 8 million –6.903 23,965,857 36,841,359
1 per 9 million –6.954 26,961,589 41,446,529
1 per 10 million –7.000 29,957,321 46,051,700

*α = 0.05 or 0.01.
†The required number of tests, all of which must be negative, is given by log (α)/log (1-prevalence); BSE, bovine spongiform encephalopathy.

*α = 0.05 or 0.01.
†The required number of tests, all of which must be negative, is given by log (α)/log (1-prevalence); BSE, bovine spongiform encephalopathy.

*α = 0.05 or 0.01.
†The required number of tests, all of which must be negative, is given by log (α)/log (1-prevalence); BSE, bovine spongiform encephalopathy.

Main Article

Page created: October 04, 2011
Page updated: October 04, 2011
Page reviewed: October 04, 2011
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
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