USAHA News
United States Animal Health Association
Contact - Larry Mark - (703) 451-3954 - webmaster@usaha.org



For immediate release:

WEST NILE, TB AND CWD FEATURED AT USAHA COMMITTEE MEETING

        GREENSBORO, N.C., Oct. 26, 2004 -- Members of the USAHA Committee 
on Captive Wildlife and Alternative Livestock heard a variety of reports 
at their meeting here this week on topics ranging from West Nile virus to 
tuberculosis in elephants and other species to chronic wasting disease (CWD) 
in deer and elk.

	West Nile virus was first introduced into the United States in 1999 
in New York City.  In the Old World, the virus cycled through mosquito vectors 
and avian reservoirs.  In the United States, West Nile virus became more 
virulent and caused mortality in crows and humans.  Within six years of 
introduction, West Nile virus had reached the west coast of the United States 
and currently the disease is endemic within the country.  

	In 2004, there were more human cases west of the Rockies than in 
the eastern United States.  There were a total of 951 cases in equines in 
2004.  Canada had its first case of West Nile virus in 2001.  Mexico saw 
increased West Nile virus activity in 2004.  The disease appears to be 
disseminating south through Central America and north along the western 
coast of Canada.  There is also a concern about mosquitoes going to Hawaii 
and introducing the disease there.

	Tuberculosis has been isolated from 30 elephants in 14 herds in the 
United States during the past ten years; all were Asian elephants.  The 
bovine form of the disease has been found in one African elephant.  There 
are several challenges in diagnosing TB in elephants.  Culture of trunk wash, 
the only approved diagnostic test, has relatively poor sensitivity.

	TB is the most important bacterial disease of captive non-human 
primates, even though it is rare in wild primates.  A new rapid test for TB 
in non-human primates shows good promise with high specificity and sensitivity.  
More work is needed before it can be officially improved.

	Tuberculosis in reindeer is extremely rare.  There was one report 
of a case in the London Zoo in 1930, but the disease has never been diagnosed 
in reindeer in the United States or Canada.  However, false positive test 
results are common and may result in quarantine and slaughter of reindeer.

	Chronic wasting disease (CWD) was first recognized in mule deer in 
a research facility in Colorado in 1967.  Currently, eight states have reported 
CWD in wild cervids and eight states have found the disease in farmed cervids.  
There are currently five known CWD-positive herds of captive cervids; three are 
elk herds in Colorado and two are white-tailed deer in Wisconsin.  

	Challenges associated with a program to control and eliminate CWD include:

	-- The disease occurs in multiple species, both free-ranging and captive.
	-- There are multiple regulative authorities and fragmented jurisdictional 
	frameworks.
	-- Farmed cervids are a relatively new livestock group.
	-- There are critical gaps in knowledge about the disease.
	-- There are limited diagnostic tools.
	
        A proposed herd certification plan published last December by USDA's Animal 
and Plant Health Inspection Service (APHIS) has a goal of eliminating CWD from 
captive cervids in the United States.  This is a voluntary program involving 
fencing requirements, animal identification and herd inventory, and surveillance 
of deaths in animals more than 16 months old.  APHIS is working with states, 
federal agencies and tribes and helped fund some of the CWD testing done during 
the past two hunting seasons.
        
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