A microscopic fungus native to Australia and blamed for the death of people and animals in British Columbia is now linked to the deaths of porpoises and at least one cat in Washington state.
EVERETT, Wash. -- A microscopic fungus native to Australia and blamed for the death of people and animals in British Columbia is now linked to the deaths of porpoises and at least one cat in Washington state.
Necropsies have that revealed cryptococcus gattii, first detected in the region on Vancouver Island in 1999, was the cause of death in six porpoises and a cat in the state, Washington's former public health veterinarian, Almira Jane Leslie, told The Herald of Everett.
The cat that died and two others that were infected with the fungus last year were in Whatcom County, which borders on British Columbia, and the porpoises were among 25 that have died in Washington state and British Columbia since 1999, Leslie said.
Except for a few isolated cases in animals in aquariums, doctors and veterinarians said it was the first time the fungus, which is invisible to the naked eye, has been documented in the United States.
It is typically found in eucalyptus trees in the tropics of Australia but also grows on other trees and can drift or be blown into water as leaves dry out. Since the fungus was discovered in Canada it has been blamed for the death at least four people, all in British Columbia.
Dogs, llamas, ferrets, pet birds and horses also have been infected, and authorities at the British Columbia Center for Disease Control estimate that 25 people become sick with cryptococcus in the province annually.
Fungal treatments are available, and medical experts do not believe it is contagious.
"It is a rare disease here, and possibly an emerging disease," said Leslie, who recently became an adjunct professor at Washington State University.
The means by which cryptococcus gattii reached North America remain unclear. Theories include a ship, a eucalyptus tree and the bottom of someone's shoes.
Another possibility is that the fungus was long present in British Columbia but became a threat to animals only with warmer weather, said Stephen A. Raverty, a veterinary pathologist with the Animal Health Center in Abbotsford, British Columbia, just north of Sumas, Wash.
"Part of the hypothesis is that because of increasing global temperatures, the environmental conditions are better," Raverty said.
Laboratory tests indicate the fungus can reproduce in salt water, and Raverty said porpoises likely become infected when tainted water enters their blow holes.
Scientists are trying to determine whether the porpoises found dead in Washington state became sick in U.S. waters or in Canada.
"It's difficult to really put this in context if there's a point source of exposure or if there (are) multiple places where these animals are exposed," Raverty said. "We expect the latter, though."
The Whatcom County cats all had different owners and apparently had not been north of the border, Leslie said.
"We think the cats acquired the illness in Washington state, and that would be a first," she said.
County Health Officer Dr. Gregory H. Stern told the Everett newspaper he has asked local doctors to test patients with prolonged coughing, fever, severe headaches, weight loss and night sweats, all signs of cryptococcus gattii:.
"We don't want people to be worried about it," Stern said. "We just want them to be prudent. If they're ill, they should get medical treatment. Their physicians will be considering it more as a cause of illness as we identify more cases."
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Information from: The Herald,
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