Worries about chronic wasting disease remain

By Linda Bell
Correspondent

Recently released figures by the Colorado Division of Wildlife regarding infection rates in culled muledeer on Larimer County open space confirms a continuing high prevalence of chronic wasting disease in some areas of northeastern Colorado.

The numbers, however, need to be understood in context, according to Fred Quartarone, DOW field coordinator for CWD.

County open spaces, where animals are concentrated and not subject to hunting, create artificial hot spots, Quartarone said. During culling, he said, the first goal is to remove infected animals followed by overall population reduction, so rates of infection possibly become inflated.

Quartarone said the DOW culled less than 500 animals in all of northeastern Colorado in 2003, and he said the agency expects to kill fewer in 2004. He said the public hunting management programs for CWD should put pressure on infected herds overall, but some "hot spots" where public hunting is not appropriate, such as the county open spaces and private land, still remain.

During a January meeting with Larimer County Commissioners to request further culling on county open lands, Quartarone said the infection rates of the small sample of animals culled in 2003 on those properties ranged from 22 percent, with two infected animals out of nine culled on Horsetooth Mountain, to 57 percent on Devil's Backbone west of Loveland, with four infected animals out of the seven culled.

Quartarone said at Eagle's Nest and Redtail Ridge open spaces an infection rate of 28 percent was based on an identical number of 14 animals culled, with four infected in each area.

Figures for Larimer County as a whole, based on hunter harvest testing, shows an infection rate range from 6.5 percent in the north to 7 percent in the south.

CWD figures for the state, based on test results from the 2003 hunting seasons from August through December, show the disease spreading west in the state for both elk and deer, but not south.

While the figures are not yet complete for the current hunter harvest, because of an extended season in some areas, numbers for the normal rifle seasons were down overall statewide because of warm dry conditions, according to the DOW. By the end of the third rifle season, hunters had submitted more than 11,000 deer, elk and moose for testing, compared with 18,000 for the previous year. Of the 11,000 tested, about 1 percent was found positive for CWD.

Mandatory moose test submission showed that to date CWD has never been detected in moose.

Meanwhile, Colorado State University researchers are about to begin an elk-breeding project to study genetic resistance to CWD at a research center near Durango, according to CSU media relations. The project is a joint research study with Cervid Research and Recovery Institute, a nonprofit entity created to conduct elk genetic research.

This genetics project will work to increase the number of elk with a CWD-resistant gene, identified by U.S. Department of Agriculture scientists several years ago through laboratory work. The gene exists in a small number of elk, including a herd owned by CRRI.

"Because we already know that animals with this gene show greater resistance to CWD, we will focus on breeding for its increased presence." said Lee Sommers, Colorado State Agricultural Experiment Station director.