An Emerging Fungal Disease in the Pacific Northwest

“Emerging diseases” are infections that occur in some new and unexpected way or are new to science altogether. The fungus found recently in a young Harbour Porpoise in British Columbia is indeed an emerging pathogen in the Pacific Northwest, for animals and people alike.

Photo courtesy of Grand Manan Whale and Seabird Research Station

In summer 2012, a four-year old male harbour porpoise (Phocoena phocoena) was found stranded on the coast of Vancouver Island. He was euthanized after he failed to respond to medical treatment and rehabilitation. The autopsy, conducted by veterinary pathologists at the Animal Health Centre in Abbotsford, B.C., found something quite unexpected.

The central nervous system was severely infected with a fungus: Cryptococcus gattii. This fungus has long been recognized as a cause of disease in tropical climates and parts of Australia. Beginning in 1999, however, this fungus was discovered in northwestern North America and was found to be causing serious disease in people, as well as a wide variety of marine and terrestrial animals. The fungus lives in the environment on trees and perhaps other vegetation and produces air-borne spores.  People and animals become infected by inhaling these spores.

In the last few years, this fungus has spread to mainland B.C. and the neighboring states of Washington and Oregon. Why it emerged here, how far it will spread and its effects on marine mammal or other populations are unknown. More information about this emerging pathogen is available at the University of British Columbia’s Cryptococcus gattii Research Website.

Author: Jamie Rothenburger

Microscopic image of the brain from a harbour porpoise. Arrows indicate C.gattii fungus