An out-of-state resident has been diagnosed with bubonic plague after recently visiting Teton County and Yellowstone National Park, the Wyoming Department of Health said Monday.

State epidemiologist Tracy Murphy says the victim traveled to several sites within the park with a Boy Scout troop between July 26 and August 3.

“The young adult traveled to Yellowstone National Park, Bridger-Teton National Forest and other sites within Teton County. He was involved in a combination of activities during his visit that included working on a service project, camping, sightseeing and participating in sports," Murphy said.

Several agencies will investigate the case, including a search for fleas and animal carcasses in the areas the victim visited.

“At this time the exact location where the exposure to the disease occurred is not known and it is likely we will never determine that level of detail,” Murphy said.

The bubonic plague has been documented in animals in 22 of Wyoming's 23 counties since records have been kept.

According to the Department of Health, this is the sixth human case of plague thought to be acquired in Wyoming since 1978.

No recent cases have come from Fremont County.

The Health Department says ways to avoid the plague include: avoiding unnecessary contact with rodents and their nests and burrows, avoiding unnecessary contact with sick or dead animals, especially rodents and rabbits, and wearing protective gloves when handling sick or dead animals, and having ill pets, such as cats and dogs, examined by a veterinarian.