# Presentation: 000008

## BSE in the USAPHIS Investigation and  Response

- FDA TSE Advisory Committee
- February 12, 2004
- Lisa A. Ferguson, DVM
- Senior Staff Veterinarian
- USDA, APHIS, Veterinary Services

## BSE Timeline

- 12/9/03 – index cow arrives at WA slaughter plant, sampled as a non-ambulatory (downer) animal
- 12/23/03 – presumptive positive BSE test results reported from NVSL
- 12/23/03 – Epidemiologic investigation begins
- 12/25/03 - Confirmation of BSE positive diagnosis
- 12/30/03 – USDA Secretary Veneman announces additional safeguards to be initiated by APHIS and FSIS.
- 1/12/04 – USDA Secretary makes declaration of extraordinary emergency providing additional authorities and funding for response (effective on 1/6/04)
- 2/9/04 – Active field investigation closed out

**Notes:**
Because the cow had no neurological signs at slaughter it was not withheld from the human food chain; however, high-risk material was diverted out of the human food supply.

## BSE Index Case - Diagnosis

- Presumptive positive diagnosis at NVSL was based on
-  immunohistochemistry
- histopathologic examination
- The positive diagnosis was confirmed at the BSE reference laboratory in Weybridge, England.  Samples from the index cow were  hand carried to this laboratory where the BSE diagnosis was confirmed on 12/25/03.

## BSE Index Case

- Holstein dairy cow, 6 1⁄2 years at slaughter
- Sent to slaughter due to calving complications
- Tested at slaughter because of non-ambulatory status, no CNS signs observed
- Trace back investigation determined cow was born into a herd in Alberta, Canada
- Moved into U.S. as part of dispersal sale in 2001
- Initially went to Mattawa, WA dairy finishing herd (9/01)
- Resided in Mabton, WA dairy herd since 10/01

## BSE Index Case (continued)

- The index cow has had four offspring over her lifetime, three calves since entering the U.S.
-  A heifer calf born in Canada
- A stillborn calf born in 2001
-  A heifer calf in born in 2002 (was in the index herd)
-  A bull calf born in 2003 – moved to a bull calf raiser in Sunnyside, WA

## Slide 6

## “At Risk” Animals Located

- “At risk” animals = 81 animals from herd in Canada
- One of the 81 is the positive cow
- 9 – index herd, Mabton, WA (131 euthanized)
- 3 - Tenino, WA (4 euthanized)
- 6 - Connell, WA (15 euthanized)
- 1 - Quincy, WA (18 euthanized)
- 3 - Mattawa, WA (39 euthanized)
- 1 – Moxee, WA (15 euthanized)
- 3 – Burley, ID (7 euthanized)
- 1 – Othello, WA (3 euthanized)
- 1 – Mabton, WA (3 euthanized)

- February 9, 2004

## BSE investigation

- Of the shipment of 81 animals from the Canadian birth herd:
- 29 accounted for (including index cow)
- Normal culling practices – estimate between 17 to 36 of the 81 might still be alive
- OIE guidelines – animals born within one year (before or after) of a BSE affected animal considered higher risk
- 25 of the shipment of 81 were in this category
- 14 accounted for (including index cow)
- Normal culling practices – estimate that 11 of the 25 might still be alive

## BSE investigation

- Total of 704 animals depopulated
- 449 – bull calf premises
- 255 – animals of interest
- 28 were part of the original 81
- 220 could have been part of the original 81
- 7 were part of additional group of 17 heifers from Canadian herd of origin

## Other parts of investigation

- FSIS - Class II voluntary recall of meat initiated on 12/24/03
- Includes 10,410 pounds
- Includes all 20 animals slaughtered on the same day as index cow
- FDA – investigation of rendered product/feed
- Over 2,000 tons of rendered protein disposed of
- Facilities in compliance with feed regulations

## International Review Subcommittee

- Delivered to Secretary’s Advisory Committee for Foreign Animal and Poultry Diseases – February 4, 2004
- Commended the US on the open and transparent manner in which the investigation was conducted
- North American “indigenous BSE”

## International Review Subcommittee

- Investigation recommendations:
- Comprehensive epi investigation, conforms to international standards
- suggested all relevant information had been obtained and recommended concluding investigation
- Tracing and recall of MBM effective and appropriate
- Tracing and recall of meat consistent with WHO recommendation

## International Review Subcommittee

- Policy recommendations
- Specified risk materials
-  remove from human and animal feed
- Recognized that FSIS interim rule (from cattle >30 months) removes highest risk tissues
- Recommend extending definition, cattle > 12 months of age
- Non-ambulatory cattle
- Maintain access for surveillance samples

## International Review Subcommittee

- Surveillance
- Test all cattle > 30 months in targeted high risk population (CNS signs, fallen stock, non-ambulatory animals, emergency slaughter, etc..) for one-year period
- Testing of all cattle slaughtered for human consumption unjustified
- Random sample of slaughter cattle >30 months could be considered to encourage reporting at the farm level
- Adopt rapid screening tests, decentralize laboratory facilities

## International Review Subcommittee

- Feed restrictions
- Recommend all SRM excluded from all animal feed
- Recommend all mammalian and poultry protein be excluded from ruminant feed
- Traceability
- Animal identification system
- Education

## BSE – Targeted Surveillance

**Non-ambulatory animals**
**Dead stock**
**Field CNS Cases and on-farm suspects**
**Veterinary Diagnostic Laboratory data**
**Public health laboratories**
**CNS condemns at slaughter and other          antemortem condemns in certain categories**

## Surveillance goals

- Surveillance at a level sufficient to find 1 case per 1 million adult cattle, 95% confidence
- Based on estimates of targeted high risk population
- Non-ambulatory – 195,000
- Broader estimate, including deads and other condemns – 600,000
- Adult cattle population – 45 million

## Surveillance goals

- FY 02 and FY 03 – goal was 12,500
- Based on estimate of non-ambulatory animals as targeted population (195,000)
- FY 04 – goal is at least 40,000
- Based on broader estimate of targeted population (600,000)
- Statistical calculation is 38,462 samples necessary, rounded up to 40,000

## BSE Surveillance – May 1990 – FY2004 (thru 12/31/2003)

**20,543**

**19,990**

**5272**

**2681**

**8,150**

**1302**

**1080**

**2713**

**1143**

**744**

**692**

**736**

**40**

**175**

**251**

## Surveillance: 
US Regions

**US Regions**

**Notes:**
Surveillance of free ranging cervids.

## US Regional GoalsBSE Surveillance  (through 12/31/03)

|  | FY01 Goal | FY01 | FY02 Goal | FY02 | FY03 Goal | FY03 | FY04
Goal | FY04 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| NW | 564 | 695 | 1,205 | 2,224 | 1,205 | 781 | 4832 | 489 |
| SW | 466 | 564 | 1,976 | 2,753 | 1,976 | 3,645 | 4172 | 470 |
| C | 766 | 332 | 1,590 | 2,356 | 1,590 | 2,628 | 6640 | 1403 |
| SC | 734 | 872 | 1,509 | 1,810 | 1,509 | 1,690 | 6380 | 1251 |
| NC | 606 | 620 | 2,561 | 3,780 | 2,561 | 5,620 | 5180 | 1990 |
| NE | 462 | 805 | 2,140 | 2,190 | 2,140 | 2,595 | 3912 | 1004 |
| E | 312 | 401 | 363 | 1,381 | 363 | 514 | 2644 | 507 |
| SE | 644 | 953 | 1,005 | 3,156 | 1,005 | 2,800 | 5580 | 1030 |

## Surveillance: NVSL Bovine Brain Submissions FY 93-04 (through 12/31/03)

## Future policy changes

- Evaluating International Review Subcommittee recommendations
- Considering range of options on surveillance
- In the interim, still committed to maintaining FY04 goal as stated, until further decisions are made
- Working with states, industry, and others to maintain access to targeted population