BSE: World update FDA TSE Advisory Committee Gaithersburg, MD September 18, 2006 Lisa A. Ferguson, DVM Senior Staff Veterinarian USDA, APHIS, Veterinary Services

Total BSE cases worldwide Cumulative total – greater than 189,000 cases Cumulative total – greater than 189,000 cases Greater than 96% in United Kingdom Greater than 96% in United Kingdom Greater than 89% occurred in 1996 and before Greater than 89% occurred in 1996 and before OIE website lists current reported totals: OIE website lists current reported totals:

EU monitoring Total of 10,113,559 bovine tests Total of 10,113,559 bovine tests 1.5 million risk animals, 8.6 million healthy slaughter 1.5 million risk animals, 8.6 million healthy slaughter 561 positive (448 in risk/suspect, 113 healthy sltr) 561 positive (448 in risk/suspect, 113 healthy sltr) Number of cases decreased by 35% from 2004 Number of cases decreased by 35% from 2004 Overall prevalence in tested animals decreased by 29% Overall prevalence in tested animals decreased by 29%

EU monitoring Reductions and increasing age of positive cases indicate success of control measures Reductions and increasing age of positive cases indicate success of control measures Analysis by year of birth of positive animals Analysis by year of birth of positive animals Peak of exposure appears well defined in some Member States Peak of exposure appears well defined in some Member States France, Ireland – 1995 France, Ireland – 1995 Germany, Belgium, Italy, Netherlands – 1996 Germany, Belgium, Italy, Netherlands – 1996 TSE monitoring in small ruminants TSE monitoring in small ruminants 614,864 tests in sheep/goats, 959 positives 614,864 tests in sheep/goats, 959 positives No confirmed BSE cases in small ruminants No confirmed BSE cases in small ruminants

EU monitoring Year Total positives Risk/suspect Healthy slaughter 20012,1531, ,1261, ,3641,

BSE in Canada Surveillance: targeted surveillance since 1991 Surveillance: targeted surveillance since 1991 Year Total # samples Positive 20035,7272* , , (to 9/8/06) 38,1475 *one case detected in US

BSE in Canada Epidemiological summary – January 2006 Epidemiological summary – January 2006 Geographic cluster theory Geographic cluster theory “Cluster” of rendering/feed/livestock production – feed distribution “Cluster” of rendering/feed/livestock production – feed distribution Links between cases Links between cases Will update this work Will update this work

BSE in Japan First identified in 2001 First identified in 2001 Feed ban imposed after diagnosis Feed ban imposed after diagnosis Surveillance primarily in clinically normal animals at slaughter until more recently Surveillance primarily in clinically normal animals at slaughter until more recently YearCases (to date) 7

BSE Surveillance in the US Active surveillance since 1990 Active surveillance since 1990 Targeting population where disease is most likely to be diagnosed – most efficient Targeting population where disease is most likely to be diagnosed – most efficient Assumption if we cannot find disease in targeted – or most likely – population, even more unlikely to be found in non-targeted population Assumption if we cannot find disease in targeted – or most likely – population, even more unlikely to be found in non-targeted population Use data obtained to extrapolate information about broader cattle population Use data obtained to extrapolate information about broader cattle population

BSE – Targeted Surveillance Non-ambulatory animals Dead stock Field CNS Cases and on-farm suspects Veterinary Diagnostic Laboratory data Public health laboratories Ante-mortem condemns at slaughter

Enhanced BSE Surveillance Total tests conducted since June 1, 2004 – through August 2006: Total tests conducted since June 1, 2004 – through August 2006:>785,000 2 positives identified during this effort 2 positives identified during this effort

BSE Enhanced Surveillance Sample Collection June 2004 – August 2006

OIE Standards for BSE Surveillance May 2005 Weighted points system Weighted points system Sample points classified to four surveillance streams: Sample points classified to four surveillance streams: Clinical suspect Clinical suspect Casualty slaughter Casualty slaughter Fallen stock Fallen stock Healthy slaughter. Healthy slaughter.

OIE Point Values Points can be accumulated over 7 years

OIE Point Distribution

BSE Prevalence in the United States Estimate using two methods: Estimate using two methods: BSurvE model BSurvE model Bayesian Birth Cohort model Bayesian Birth Cohort model Sensitivity analyses Sensitivity analyses Conclusion: Conclusion: BSE prevalence is less than 1 infected animal per 1 million adult cattle. BSE prevalence is less than 1 infected animal per 1 million adult cattle. Most likely values ( with upper and lower 90% confidence levels ) Most likely values ( with upper and lower 90% confidence levels ) BSurvE - 7 (3,24) infected animals in adult cattle population BSurvE - 7 (3,24) infected animals in adult cattle population BBC – 4 (1,8) infected animals in adult cattle population BBC – 4 (1,8) infected animals in adult cattle population

Ongoing BSE Surveillance Plan Launched August 28, 2006 Launched August 28, 2006 Approximately 40,000 samples per year Approximately 40,000 samples per year Continue to monitor the status of U.S. cattle Continue to monitor the status of U.S. cattle Able to detect increasing BSE prevalence Able to detect increasing BSE prevalence

Ongoing BSE Surveillance Sample size calculation, based on analysis of enhanced surveillance data and BSurvE model Sample size calculation, based on analysis of enhanced surveillance data and BSurvE model More sensitive design prevalence of 1 case per 1 million adult cattle More sensitive design prevalence of 1 case per 1 million adult cattle BSurvE used to estimate sample numbers and points BSurvE used to estimate sample numbers and points 3,000,000 analytical points necessary 3,000,000 analytical points necessary Average 9.5 analytical points per sample in enhanced Average 9.5 analytical points per sample in enhanced Assume higher average points, require approximately 40,000 samples per year Assume higher average points, require approximately 40,000 samples per year