Brucellosis and bison/URLs

Michele Gale-Sinex/CIAS, UW-Madison (mgs@aae.wisc.edu)
Thu, 13 May 1999 18:36:55 -0500

Howdy all--

Regarding the item I posted from ProMED regarding the ongoing
slaughter of the Yellowstone bison herd, in part:

>BRUCELLOSIS, BISON - USA (MONTANA): CONTROL
>***************************
>
>A federal appeals court refused Thursday to stop Montana from
>slaughtering bison outside Yellowstone National Park to prevent the
>animals from infecting cattle with brucellosis, a serious livestock
>disease. Bison leave Yellowstone in search of winter forage. About
>half test positive for brucellosis, a disease that can cause cows to
>abort and, in rare cases, can spread to humans and cause a recurring
>fever.
>
>In a one-sentence ruling, the 9th U.S. Circuit Court of Appeals
>upheld a federal judge's decision allowing the state and the National
>Park Service to continue killing bison as they have for the last 3
>winters.

This AP Online story--as so many major media stories about
agriculture or anything west of the Hudson River--implies that the
Yellowstone bison have been infecting cattle with brucellosis. Which
is playing fast and loose with the facts.

Douglas pointed out that the major vector of /Brucella aborta/
transmission is sexual contact, and that bison and cows are not
likely to make simpatico lovers.

Another vector is the licking of newborn calves (to remove the
afterbirth); cows would not be likely to groom newborn bison calves
(can't imagine Mama Bison allowing that...). Or the drinking of
infected milk (can't imagine Mama Bison nursing a cow...).

But what the heck do I know, cheezer and all. :^)

The irony here is that cattle were the original carriers of
/Brucella aborta/: they infected the bison. Another irony: the
Yellowstone elk (wapiti) herd carries /B. aborta/--in higher
proportion than the bison herd--as do other animals in the park.

I've not been able to uncover a single documented case of a cow in
that rangeland contracting brucellosis from those bison. However,
I'm still looking.

A bison exposed to /B. aborta/ will develop antibodies, which will
then cause it to test positive. (Similar to HIV testing--testing for
the antibody indicates exposure at some point in the past.) But this
doesn't mean that the animal has or can necessarily transmit
brucellosis. The test-and-slaughter program, however, makes no such
distinctions.

I can understand the concern from an epidemiological point of view.
I recently overheard a well-heeled Madisonian opine, in a discussion
about the head louse outbreak in his child's day care center, "I
don't see why they have to report a kid for having just one or two
eggs! [nits]" Ah, right; here's a nice pair of pet cockroaches for
you.

At the same time...well, it's more complicated than that.

If interested, check out this interesting detailed discussion from
2/97, appearing in the regional newspaper /High Country News/:

http://www.hcn.org/1997/feb17/Index_293.html

You can get some earlier and later news on this topic from /HCN/ by
using the site's search engine; try "brucellosis."

If you'd like to see the program of research that USGS is conducting:

http://www.mesc.nbs.gov/research_briefs/Bison_Brucellosis.html

Montana State U.--Bozeman's Center for Bison Studies offers this
bibliography, /Brucellosis in the American bison, //Bison bison L.//
and related wildlife/:

http://www.montana.edu/wwwcbs/brucbib.html

peace
misha

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Michele Gale-Sinex, communications manager
Center for Integrated Ag Systems
UW-Madison College of Ag and Life Sciences
Voice: (608) 262-8018 FAX: (608) 265-3020
http://www.wisc.edu/cias/
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Pressure? Pressure was when I was a shoeshine boy
trying to make it to America. --Sammy Sosa

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