If you go down to the woods today you might want to hold your breath. A deadly microscopic fungus first detected in 1999 in some of the most scenic forested parks of Vancouver Island is spreading, mutating and gaining strength, warns an international study released last week. The fungus, Cryptococcus gattii (C. gattii), was once thought to exist only in the tropics. Today, its “epicentre” is Vancouver Island, but it has spread to B.C.’s Lower Mainland, to Washington state and to Oregon, where a “highly virulent” strain has been found, says Duke University microbiologist Edmond J. Byrnes III, the study’s lead author. Climate change is the suspected cause of the spread. Some 220 people in B.C. have fallen ill since 1999, one of the highest rates in the world. Fifty cases have been reported in the U.S. About 40 people have died in both countries.
The symptoms begin with a persistent cough, starting as long as seven months after contact. They can escalate to weight loss, night sweats, pneumonia and meningitis, says the B.C. Centre for Disease Control (BCCDC). If diagnosed in time, the infection can usually be treated with anti-fungal medications.
While fatalities are rare, the spread of C. gattii into the temperate Pacific Northwest is “alarming,” the study says. The spores live in trees and soil. They are usually spread through the air, but they can be tracked on the soles of shoes and can survive in salt water. Cats, dogs, ferrets, sheep, elk and even porpoises are also falling ill, the study says.
There are no realistic precautions to avoid infection. The spores are invisible to the naked eye. In fact, “most people” have been exposed to the fungus, says information posted on the BCCDC website, “and most of these will not get sick.”
That’s one of the troubling questions still to be answered: why a walk in the woods can be deadly for a rare few.