© Environment News Service (ENS) 2001
July 17, 2001

FORT SMITH, Alberta, Canada, July 17, 2001 (ENS) - Parks Canada officials have discovered an outbreak of anthrax among the bison in Alberta's Wood Buffalo National Park.

There is a 40 year history of anthrax amongst the bison in the park, which covers an area the size of Switzerland. Now a UNESCO World Heritage Site, the park was established in 1922 to protect the last remaining herds of bison in northern Canada.

Park Warden Jonah Mitchell says the first cases this year were found June 22 by RCMP police on a helicopter overflight of the Peace Athabasca Delta. Six helicopter surveys of the area since have turned up 41 dead bison - 23 bulls, 18 cows, and three calves.

Last year, using heat seeking helicopters, officials found 103 anthrax infected bison carcasses.

Anthrax can be transmitted to humans, and personnel who deal with the infected carcasses all don protective gear, full body suits and gloves.

The Sweetgrass area where the stricken bison were found has been closed to visitors. It extends along a peninsula on the northeastern shore Lake Clair up to a mile south of the Peace River, over to Baryl Lake on the east - a band of land covering 341 square kilometers, about .008 percent of the enormous park.

Speaking for Parks Canada, Mike Keizer says it is usually canoeists who want to explore the remote Sweetgrass wilderness of boreal forest and rolling grass prairies.

Twelve trips went through before the anthrax was discovered, but a visitor registration system is in place, and the main landing areas are posted with signs. Keizer is advising journalists across North America to inform their audiences about the anthrax in Sweetgrass.

There are three ways to get anthrax - inhalation, ingestion and through the skin. Most of the bison are getting it by inhalation, says Keizer. Spores in the ground can be brought up by the right combination of environmental conditions. Wallowing bison will breathe them in.

Wood bison bulls display by generating a high column of dust from their individual wallows, says Mitchell. As wallows have the potential to collect anthrax spores, it has been hypothesised that this dust column, if it contained spores, could infect bulls in the vicinity.

Last year, two bears were found dead of anthrax contracted by ingestion, they had been seen scavenging dead bison carcasses.

Cutaneous anthrax occurs when anthrax enters an open cut. It is treatable with penicillin, and staff who deal with anthrax get a precautionary dose of penicillin, Keizer says.

After unsuccessfully attempting to burn or bury the infected carcasses in the past, this year, parks staff is just leaving them in place and monitoring them as they decompose.

Keizer says burying just puts off the problem as the anthrax spores come to the surface eventually. Burning reduces but does not eliminate the spores. The parks personnel have tried covering the carcasses with lime in an effort to keep scavengers away, but that has not been successful.

Treatment of the bodies with formaldehyde has met with some success, but the chemical is a carcinogen. "The solution can't be worse than the problem," says Keizer.

There is no danger that the anthrax will spread to domestic livestock. "We are such a long way from anything, Keizer says. Animals don't tend to move very far once infected. Within 48 hours after infection, they die."

Parks officials have had to deal with brucellosis and tuberculosis in bison up on the northern border of the huge park. The park extends into the Greater Northwest Territory where a bison containment zone is in place. If bison are seen out of the park, they will be harassed back within its borders, and if that does not work, they are killed. Error: Unable to read footer file.