Comment from Gregory a Ledbetter, Idaho Department of Agriculture

Re: Docket No. APHIS-2006-0001 Thank you for the opportunity to comment on the reclassification of Idaho from Brucellosis Class Free to Class A. These comments are divided into two sections. First, we have some general comments regarding the Brucellosis Program and then specific comments regarding this docket. Idaho believes that the brucellosis provisions of the Code of Federal Regulations and the UM&R do not reflect the unique situation that exists in the Greater Yellowstone Area of Idaho, Montana, and Wyoming. The current regulations were written to deal with the transmission of brucellosis from one cattle herd to another. There is no provision to deal with an occasional cattle herd that is infected by wild free ranging wildlife. We strongly believe that APHIS must amend the regulations to reflect current situations. The state of Idaho believes that APHIS should not have changed Idaho?s brucellosis status from Class Free to Class A for the following reasons. One herd in Eastern Idaho was found through MCI traceback to be infected with brucellosis by association with a wild, brucellosis-affected elk herd. A heifer from the infected herd was moved into a small pen on another premises. The heifer, weighing approximately 480 pounds, was purchased at the livestock market on 8/10/05. She was vaccinated with RB51 vaccine, and moved into a small pen of fourteen other calves consisting of young steers and heifers. No bull was present at any time in this group. The heifer resided in this group from August 10, 2005 until the group was depopulated on December 6, 2005. As part of the traceback testing, she was sampled on 11/02/2005 and 11/16/2005 and tested at the Idaho State Department of Agriculture Lab. Results of the Standard Plate and Rivanol tests were in the Negative range both times. Compliment Fixation test results were 1+ at the 1:80 dilution and 3+ at the 1:40 dilution respectively. A sample of the serum was forwarded to Dr. Phil Elzer at LSU for Western Blot analysis, where Dr. Elzer reported the results as ?Yersinia positive with Brucella background (may be due to vaccine or exposure)?. The heifer?s serum from the 11/16/05 blood collection was tested at NVSL with results on Standard Plate ? Negative, Rivanol ? Inconclusive, and Compliment Fixation ? 2+ at the 1:80 dilution. This heifer was sampled at slaughter on 12/6/2005, and appropriate tissues submitted for culture to NVSL were Negative (no growth reported). According to CFR 78.1, if a single herd in a Class Free State is found to be affected with brucellosis, the State may retain its Class Free Status if the affected herd is quarantined, tested, and de-populated. This was accomplished in an appropriate time frame. And, an epidemiological investigation must be performed to confirm that brucellosis has not spread from the affected herd. This also was accomplished in an appropriate time frame, and from which this above-mentioned heifer was found. Every possible method of testing was performed to discover the reason for the heifer?s serological test results. In spite of the fact that she originated from a brucellosis infected herd, she CANNOT be positively diagnosed with field strain Brucella abortus since she tested positive to Yersinia, and no Brucella organism was cultured from her tissues. No other heifers in the herd she was moved into tested positive for Brucella abortus, and according to Dr. Phil Elzer and Dr. Fred Enright of L.S.U., a non-pregnant heifer, even if she were infected with Brucella abortus, will not shed the organism until she is parturient1, which she was not. The possibility remains that the serological test results are due to Yersinia and / or RB51 vaccination. We have recently proved (co-incidentally in an Idaho cow) that serological results in the suspect or reactor range can, in fact, be due to RB51 vaccination. The RB51-vaccinated cow had no history whatsoever of exposure to field strain Brucella and was proven to be a RB51-shedder by culture of the RB51 organism from her milk by Idaho State Department of Agriculture Animal Health Lab and NVSL. This cow was shown by Western Blot at Dr. Elzer?s lab to also be Yersinia positive. USDA statements that transmission via any discharge containing Brucella abortus bacteria is possible and that the organism has been found in the urine and feces of infected animals are true if the animal is parturient. However, this heifer was not pregnant and no Brucella abortus was cultured from tissues where it would have been transmitted from. Dr. Enright and Dr. Elzer could not recall any study proving that a non-pregnant heifer has passed B. abortus in her urine or feces.1 The only reference mentioning the organism in nursing calves? feces is designated a ?historical document?. 2 Recent literature with references state that it is generally accepted that B. abortus is not excreted for any considerable time before abortion occurs.3 And, brucellosis is a disease of sexually mature animals.4 Other literature refers to Brucella abortus found in urine contaminated with uterine and vaginal discharges of aborted (suggesting they were pregnant), or parturient cows as well as environmental urine from these animals as a source of infection for other cattle.3, 4, 5, 6, 7 This heifer, like all other animals that left the infected herd, was moved into a new group. The disease did not ?spread? into a second herd, especially if she is only carrying Yersinia or RB51. Clearly, if the heifer is not pregnant, and B. abortus cannot be grown from her tissues that usually harbor the organism, then she cannot be considered infected and she is not capable of infecting, ?spreading?, or otherwise transmitting the organism to other cattle. In conclusion, because of the specific facts of this case and in light of the recent discovery of the Yersinia infected cow/ RB51 shedder, the state of Idaho believes that APHIS should reinstate Idaho?s Brucellosis Class Free Status immediately. Gregory A. Ledbetter, DVM, MPVM Administrator, Division of Animal Industries Idaho Department of Agriculture References 1. Personal conversation with Dr. Fred Enright, and Dr. Phil Elzer, faculty, Louisiana State University, Department of Veterinary Science, brucellosis research. 2. Brucellosis of Cattle, McMahan VK, Circular 222, Agricultural Experiment Station, Kansas State College of Agriculture, Department of Veterinary Medicine, Historical Document, April 1944. 3. Bovine Brucellosis Disease Card, Food and Agriculture Organization of the United Nations website, Animal Production and Health Division at www.fao.org, 113 references. 4. Brucellosis, Food and Agriculture Organization of the United Nations website article, AVIS Consortium at www.fao.org 5. Brucella, Richard L. Walker, Chapter 16, Veterinary Microbiology, 2nd edition, Blackwell Publishing, 2004. 6. Bioterrorism & Agroterrorism Awareness Education CD, Brucellosis powerpoint speaker notes, Davis R, Bicket-Weddle D, Center for Food Security and Public Health, Iowa State University, 2004. 7. Brucellosis in Cattle, The Merck Veterinary Manual, 8th ed., pp. 998- 1000, Merck & Co., 1998.