Human and animal infections caused by the pathogenic fungus Cryptococcus gattii emerged on Vancouver Island, British Columbia (BC), Canada, in 1999. Typically Cryptococcus gattii is considered to be restricted to tropical and sub-tropical climates e.g. Australia, Africa, and India. Therefore it is surprising that Cryptococcus gattii is the cause of disease in the temperate climate of BC.

Cryptococcus gattii infection in BC was first identified in 2001, when BC veterinarians noticed an unusually high number of animals becoming sick with cryptococcal disease, including cats and dogs, horses, llamas, and ferrets from Vancouver Island, as well as porpoises in the waters surrounding the island. At the same time, a higher than normal number of infections was noticed in humans. The infections were determined to be caused by Cryptococcus gattii, which is well known in Australia but never before reported in Canada. After reviewing medical charts, public health officials at the BC Centre for Disease Control were able to determine that there had been Cryptococcus gattii infections in humans as far back as 1999 that were not recognized at the time because the fungus was not expected to exist in Canada. Since 2001, a team of experts from the University of BC, BC Centre for Disease Control, Vancouver Island Health Authority, the Centre for Coastal Health and the Central Laboratory for Veterinarians have been working together as the BC Cryptococcal Working Group, to investigate cryptococcal disease in humans and animals, as well as the distribution of Cryptococcus gattii in the environment.

Cryptococcus gattii was first identified in the environment in March of 2002, among trees in Parksville on Vancouver Island, close to the homes of some of the humans and animals who had been infected with the fungus. Since then many different types of trees have tested positive for Cryptococcus gattii on Vancouver Island. Dr. Karen Bartlett and her research team have established the presence of Cryptococcus gattii on trees, in soil, in the air, and in water at many different areas of Vancouver Island. Recently, Cryptococcus gattii has been detected in air samples on the BC lower mainland.