JACKSON (AP) - A survey by the Wyoming Game and Fish Department suggests that 14 percent of the elk wintering on the National Elk Refuge near Jackson have been exposed to brucellosis, a far higher rate than in areas where the state doesn't feed elk during the winter.

The department drew samples from elk shot by hunters last fall. While 14 percent of the elk on the refuge and in Grand Teton National Park showed exposure to brucellosis, the agency said surveys in southwest Wyoming, where elk aren't fed, showed a rate of exposure lower than 1 percent.

The survey also tested bison killed by hunters in Jackson Hole. It found 66 percent of the animals were positive for exposure to the disease, compared to a five-year average of 60 percent.

Wyoming lost its brucellosis-free status in 2004 when the disease was found in cattle herds near state elk feedgrounds. The state is researching and testing for the disease as part of its efforts to regain its brucellosis-free status. The disease can cause pregnant cows to abort their fetuses.

In the recent survey, successful hunters on the elk refuge and the national park submitted 182 usable blood samples, of which 14 percent tested positive for exposure to the disease.

Only one elk out of 343 tested in southwest Wyoming during the same hunting season showed exposure to the disease, the department says. A similar survey of elk in northeast Wyoming the year before found no exposed elk.

Although feedgrounds are considered a place where disease spreads among wildlife, there's significant political pressure to continue the winter feeding programs around Jackson and Pinedale.

"The animals targeted in this hunter surveillance included those that would likely spend the winter on the National Elk Refuge," said Chris Colligan, brucellosis information and education specialist with the game department. Not all of the animals that have been exposed to the disease are actually infected.

"We were really successful in obtaining a large sample size this year," said Jill Miller, brucellosis feedground habitat biologist who led the surveillance program in Jackson. "Without (hunters') cooperation, we would have been unable to survey the health of this herd."