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From: TSS ()
Summary of Enhanced BSE Surveillance in the United States Prepared by Centers for Epidemiology and Animal Health National Surveillance Unit April 27, 2006 2 Summary of Enhanced BSE Surveillance in the United States Introduction Since 1990, the U.S. Department of Agriculture (USDA) has taken aggressive measures to prevent the introduction and potential spread of bovine spongiform encephalopathy (BSE). Following the confirmation of BSE in an imported cow in December 2003, USDA designed and implemented an Enhanced BSE Surveillance Program to more accurately determine the level of disease present in the U.S. cattle population. The following report summarizes the data collected during the Enhanced BSE Surveillance Program as well as the information gathered from earlier surveillance efforts. The Enhanced BSE Surveillance Program tested as many cattle as possible in the targeted high-risk population beginning June 1, 2004. Collection at an enhanced level has continued beyond 18 months to ameliorate concerns of trading partners. Experience in the United Kingdom and Europe has shown that if present, BSE is most likely to be detected in adult cattle exhibiting clinical signs consistent with the disease. Base Estimate of High Risk Population In general, the highest risk categories are adult cattle showing clinical signs involving the central nervous system (CNS), and dead and non-ambulatory cattle with clinical signs that could not be adequately evaluated. This population was estimated to total 445,886 adult cattle per year in the United States. This number was derived in part from National Animal Health Monitoring System (NAHMS) surveys of livestock producers and other estimates. Specifically, in the 1997 NAHMS breeding beef cattle survey,1 U.S. producers reported that approximately 1.5 percent of the adult cattle population died annually. Producers attributed these losses to a variety of causes including digestive, respiratory, weather, and calving-related problems, as well as other known and unknown causes. Similarly, in 2002, NAHMS data estimated that 4.8 percent of adult dairy cows die annually. Again, these losses were attributed to various causes. Calculations resulted in an estimate that 251,532 adult cattle die on-farm each year for unknown reasons, or reasons that could be consistent with BSE-related clinical signs.2 In addition, other described populations include 194,225 animals in the Food Safety and Inspection Service (FSIS) condemnation categories, and 129 reported foreign animal disease (FAD) investigations related to CNS abnormalities. These totals provide the basis for USDA’s estimate of 445,886 adult cattle per year in the targeted high-risk population. 1 NAHMS Part I: Reference of 1997 Beef Cow-Calf Management Practices. USDA:APHIS:VS: CEAH, National Animal Health Monitoring System. June 1997. Fort Collins, CO. #N238.398. 2 NAHMS Part I: Reference of Dairy Health and Management in the United States. National Animal Health Monitoring System. 2002. Fort Collins, CO. #N377.1202. 3 This estimate includes adult cattle in the following categories: • Condemned at slaughter for CNS signs; • Moribund; dead; injured or emaciated (FSIS data 2002); • CNS abnormalities reported for FAD investigations (APHIS data 2003); • Died on-farm of unknown causes; • Lameness or injury that resulted in euthanasia; and • Cattle that died with signs of incoordination or severe depression. The sampling strategy was designed to target animals in these categories. Designation of Samples Collected during Enhanced BSE Surveillance Samples collected during the enhanced surveillance period were designated as “targeted” and “non-targeted.” Samples with valid test results having any of the following reasons for submission, regardless of age or other criteria, were categorized as “targeted” in the enhanced surveillance program: • Highly suspicious for BSE; • CNS signs; • Rabies suspect; • FSIS antemortem condemnation code of “CNS signs” or “rabies.” Other samples collected during the period associated with the enhanced surveillance that did not meet the above criteria were considered as follows: • Samples with a reason for submission of “FSIS antemortem condemnation” were recorded as targeted only if the condemnation code listed nonambulatory, injuries, tetanus, dead, or moribund. In addition, the sample must have originated from cattle with a recorded age of 30 months or older, or from cattle with a recorded age of 24 to 29 months with the second set of incisors erupted.3 • Samples with a reason for submission of nonambulatory, dead, or other clinical signs that may be associated with BSE were recorded as targeted if they originated from cattle with a recorded age of 30 months or older, or from cattle with a recorded age of 24 to 29 months with the second set of incisors erupted. • Samples with a reason for submission of “apparently healthy animal at slaughter” were recorded as targeted if they were collected at a slaughter plant and they originated from cattle with a recorded age of 30 months or older, or with the second set of incisors erupted. 3 Eruption of at least one of the second set of permanent incisors was used as the criterion upon which cattle were determined to be at least 30 months of age. 4 Samples with the following invalid test results were not included in the targeted population and were excluded from this report: • Samples in which submitted tissue was not obex;4 and • Samples not tested or where results have not been recorded in the BSE Surveillance database. Between June 1, 2004, and March 17, 2006, BSE samples were collected from 5,776 unique locations across the United States. These locations included slaughter plants, renderers, farms, public health laboratories, veterinary diagnostic laboratories, and salvage slaughter (3D-4D)5 plants. Overall, 647,045 samples were designated as “targeted” based on the enhanced surveillance criteria discussed above. Among these samples USDA identified two confirmed positives over this time period (0.0003 percent test positive). Table 1 summarizes the number of samples from each type of collection site. Sample collectors were required to categorize submissions into one of eight submission type categories. These categories were not those provided in the World Organization for Animal Health (OIE) Code for BSE surveillance, but offered a greater level of detail that facilitated later classification into the OIE surveillance streams. ...SNIP...FULL TEXT 23 PAGES; http://www.aphis.usda.gov/newsroom/hot_issues/bse/content/printable_version/SummaryEnhancedBSE-Surv4-26-06.pdf DRAFT 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 THIS INFORMATION IS DISTRIBUTED SOLELY FOR THE PURPOSE OF PRE-DISSEMINATION PEER REVIEW UNDER APPLICABLE INFORMATION QUALITY GUIDELINES. It has not been formally disseminated by the Animal and Plant Health Inspection Service. It does not represent and should not be construed to represent ANY Agency DETERMINATION OR policy. DRAFT DRAFT DRAFT 4 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 , 8) (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 1 Vose Consulting U.S. LLC, 14 Green Street, Princeton, NJ 08542, USA, www.risk-modelling.com. DRAFT DRAFT DRAFT 5 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. SNIP...FULL TEXT 43 PAGES http://www.aphis.usda.gov/newsroom/hot_issues/bse/content/printable_version/BSEprevalence-estimate4-26-06.pdf PEER REVIEW PLAN http://www.aphis.usda.gov/about_aphis/printable_version/peer_review_plan_prevalence4-28-06.pdf http://www.aphis.usda.gov/about_aphis/printable_version/peer_review_plan_prevalence4-28-06.pdf ============================================== USDA To Release Analysis Of US BSE Testing Friday On June 1, 2004, the USDA sharply boosted the number of cattle it was testing for BSE in response to the December 2003 discovery of the first BSE case in the U.S. The effort, an "enhanced" BSE surveillance program, was designed to assess the prevalence of BSE in U.S. herds. Since then, the USDA has tested nearly 700,000 cattle and found two more cased of the disease, making the total number found in the U.S. three. http://www.cattlenetwork.com/content.asp?contentid=32789 ========================================= The USDA June 2004 Enhanced BSE surveillance program was a sham, and everyone knows it now. I find it sad and embarrassing that the USDA and my country, would continue this masquerade. I find it even more sad that the public accepts it. THE complete program, and the USDA should be dismantled and redone. Those test were meaningless under there flawed BSE protocols. ...TSS CDC DR. PAUL BROWN TSE EXPERT COMMENTS 2006 The U.S. Department of Agriculture was quick to assure the public earlier this week that the third case of mad cow disease did not pose a risk to them, but what federal officials have not acknowledged is that this latest case indicates the deadly disease has been circulating in U.S. herds for at least a decade. The second case, which was detected last year in a Texas cow and which USDA officials were reluctant to verify, was approximately 12 years old. These two cases (the latest was detected in an Alabama cow) present a picture of the disease having been here for 10 years or so, since it is thought that cows usually contract the disease from contaminated feed they consume as calves. The concern is that humans can contract a fatal, incurable, brain-wasting illness from consuming beef products contaminated with the mad cow pathogen. "The fact the Texas cow showed up fairly clearly implied the existence of other undetected cases," Dr. Paul Brown, former medical director of the National Institutes of Health's Laboratory for Central Nervous System Studies and an expert on mad cow-like diseases, told United Press International. "The question was, 'How many?' and we still can't answer that." Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive. USDA officials finally retested the cow and confirmed it was infected seven months later, but only at the insistence of the agency's inspector general. "Everything they did on the Texas cow makes everything USDA did before 2005 suspect," Brown said. ...snip...end http://www.upi.com/ConsumerHealthDaily/view.php?StoryID=20060315-055557-1284r We have to be careful that we don't get so set in the way we do things that Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren't Dr. Keller: Tissues are routinely tested, based on which tissue provides an Dr. Detwiler: That's on the slaughter. But on the clinical cases, aren't FOR IMMEDIATE RELEASE Contact: Kate Cyrul – IG Report finds agency officials overruled advice of field scientists – WASHINGTON, D.C. – Congresswoman Rosa L. DeLauro (Conn.-3) today questioned the reasoning of officials at the Animal and Plant Health Inspection Service (APHIS) that overruled the advice of field scientists on the retesting of a domestic cow found to have the bovine spongiform encephalopathy (BSE) disease. After the USDA announced that the first case of BSE was identified in a native-born cow last June, officials at APHIS said no further testing of the animal was needed. The USDA’s inspector general, however, determined the testing used proved inconclusive results and said that a sample from the cow should be sent for further testing. DeLauro is ranking member of the House Appropriations Agriculture subcommittee, which has jurisdiction and oversight responsibilities of USDA and FDA. “I am concerned that the APHIS officials that reviewed these results seemed to make decisions based not on science, but on the economic ramifications a positive BSE finding in a domestic born animal could have on the U.S. economy,” said DeLauro. “When consumer safety is in question, APHIS should not be forced into additional testing of an inconclusive sample by its inspector general. “While we are glad that this cow did not enter the human food supply, APHIS officials had a responsibility to further examine this sample that even our “gold standard” test proved inconclusive. By refusing to send samples for further testing, APHIS could have jeopardized consumer health and safety and put the industry at a disadvantage, drawing into question the safety of our beef. “Today I am requesting that APHIS disclose which officials made this decision and further explain their reasoning for not voluntarily testing this inconclusive sample further.” ### http://www.house.gov/delauro/press/2006/February/APHIS_retesting_2_3_06.html Audit Report Animal and Plant Health Inspection Service Bovine Spongiform Executive Summary Animal and Plant Health Inspection Service - Bovine Spongiform Results in Brief This report evaluates elements of the interlocking In June 2004, APHIS implemented its expanded surveillance program; USDA made significant efforts to implement the expanded BSE surveillance 41 Protocol for BSE Contract Laboratories to Receive and Test Bovine Brain 42 The NVSL conducted an ELISA test on the original material tested at the 43 A visual examination of brain tissue by a microscope. 44 A localized pathological change in a bodily organ or tissue. SNIP... [GAO-05-101 ] Mad Cow Disease: FDA's Management of the Feed Ban Has Improved, but Oversight Weaknesses Continue to Limit Program Effectiveness [GAO-05-101 ] Mad Cow Disease: FDA's Management of the Feed Ban Has Improved, but Oversight Weaknesses Continue to Limit Program Effectiveness http://frwebgate.access.gpo.gov/cgi-bin/useftp.cgi?IPaddress=162.140.64.88&filename=d05101.txt&directory=/diskb/wais/data/gao 03-025IFA Subject: Substances Prohibited from Use in Animal Food or Feed, Proposed Rule, Docket No. 2002N-0273 C-534 VOL 45 (PhRMA) and Entered On February 17, 2006 Marie A. Vodicka, PhD Assistant Vice President Biologics & Blotechnology Scientlflc & Regulatory Affairs SCIENCE & REG AFFAIRS Division of Dockets Management (HFA-305) Food and Drug Administration 5630 Fishers Lane, rrn . 1061 Rackville, MD 20862 No. 2002N-0273 February 14, 2006 Dear Sir or Madam : The Pharmaceutical Research and Manufacturers of America (PhRMA) is providing comment to the proposed rules issued. ...... Subject: Docket No: 2002N-0273 (formerly Docket No. 02N-0273) Substances Prohibited From Use in Animal Food and Feed PAUL BROWN December 20,2005 Division of Dockets Management (HFA-305) Food and Drug Administration 5630 Fishers Lane Room 1061 Rockville, MD 20852 Re: Docket No: 2002N-0273 (formerly Docket No. 02N-0273) Substances Prohibited From Use in Animal Food and Feed Dear Sir or Madame: As scientists and Irecognized experts who have worked in the field of TSEs for decades, we are deeply concerned by the recent discoveries of indigenous BSE infected cattle in North America and appreciate the opportunity to submit comments to this very......... oral route with just .OO1 gram of infected tissue, it may not take much infectivity to contaminate feed and keep the disease recycling. ........ December 19, 2005 Division of Dockets Management (HFA-305) Food and Drug Administration 5630 Fishers Lane Room 1061 Rockville, MD 20852 Re: Docket No: 2002N-0273 (formerly Docket No. 02N-0273) Substances Prohibited From Use in Animal Food and Feed Dear Sir or Madame: The McDonald’s Corporation buys more beef than any other restaurant in the United States. It is essential for our customers and our company that the beef has the highest level of safety. Concerning BSE, ........... THE SEVEN SCIENTIST REPORT *** http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf TSS
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