Cryptococcus gattii: an emerging cause of pulmonary nodules

Since the fall of 1999, a new endemic focus of Cryptococcus gattii serotype B infection has emerged on Vancouver Island (Victoria, British Columbia), with infections occurring in both animals and humans. In the human cases, symptoms have manifested as pulmonary nodules, meningitis or both. This organism has added a new nonmalignant cause of pulmonary nodules to the literature, resulting in a change in the management of these nodules by health care professionals.

A search of the number of cases recorded and treated in hospitals of the Vancouver Island Health Authority, along with a review of the literature regarding this emerging organism, was undertaken. The pathology, epidemiology and clinical course of this previously uncommon fungus was determined, and representative cases were chosen for illustration.

More than 130 cases were recorded in the six-year period from late 1999 to mid-July 2006. The number of cases increased steadily over this period, but appears to be levelling off. Representative cases with medical imaging, along with photos of the pathology, are included. Recommendations for diagnosis, treatment and follow-up are outlined.

The emergence of cryptococcal lung and central nervous system lesions on Vancouver Island have made it important to include travel to or residence of the island as part of the history in patients with pulmonary nodules. A registry of patients from Vancouver Island has been established, and it may be of value to include nonisland patients who are found to be infected with this organism.