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An
Initiative to Enhance Brucellosis Vaccines, Vaccine Delivery and |
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Briefing
Statement, May 2005 During
the 2004 Annual Meeting of the United States Animal Health Association (USAHA),
incoming president Dr. Rick Willer appointed a special committee to
address shortcomings in the current brucellosis eradication effort in the
Greater Yellowstone Area (GYA). The Special Committee was charged with
conducting a workshop with experts from state, federal, academic and
private sectors that will generate a report to the president at the 2005
USAHA Annual Meeting. Goals:
Recognizing the challenges of
eliminating brucellosis from free-ranging wildlife, the Special Committee
established three primary goals for the more than 50 workshop
participants: 1. address
research needs for new and improved vaccines that are safe and effective
for use in free-ranging bison and elk; 2. consider alternatives to vaccine
delivery systems for wild species; and 3. improve live-animal diagnostic
capabilities for identifying infected animals. Background:
The GYA is one of the largest intact temperate zone ecosystems in
the world, encompassing roughly 28,000 square miles in Montana, Idaho and
Wyoming and is home to an estimated 100,000 elk, 5,000 bison and
widespread livestock on public and private lands.
Brucellosis
was first identified in the region in bison in 1917. Although the source
remains unconfirmed, scientists believe the wildlife was initially
infected via commingling with diseased livestock. The disease has
perpetuated in the wild environment, making the GYA the last major
reservoir of B. abortus in the
United States.
National
eradication efforts in the domestic livestock and captive wildlife
populations have proven very successful.
Estimated
infection rates within the GYA vary, from lows of 1% to 3% in the
northern-most elk herds, to highs of 15% to 60% in southern feeding
grounds. Likewise, bison seroprevalance levels range from 40% to 50% in
Yellowstone to as high as 70% to 80% in those frequenting the National Elk
Refuge feedground. Presently, brucellosis management programs are based on
serologic tests that identify, at a minimum, exposure to unknown levels of
B. abortus.
Vaccines are a useful tool in disease eradication programs, but
potential new vaccines also need to be tested for safety and efficacy in
bison and elk. Delivering
those vaccines, safely and effectively, is also a challenge in the GYA
brucellosis eradication effort. Additional
Details:
The Workshop is being held, August 16-18, 2005, at the University
of Wyoming, Laramie. Sessions, facilitated by the University’s
Ruckelshaus Institute, will be open to the public, with opportunities for
public comment. Information
about the Ruckelshaus Institute is available on the web at www.uwyo.edu/enr.
Serving
as host to the workshop is the United States Animal Health Association,
the nation’s animal health forum for more than a century, as a
science-based, nonprofit, voluntary organization. Information about USAHA
is available on the web at www.usaha.org.
Source: USAHA News Flash |