A yeast or fungus, Cryptococcus gattii (C. gattii), is spreading into California from Canada, Washington, and Oregon. When airborne spores are inhaled, this fungus can cause a disease known as cryptococcosis in people and animals. While early reports of infection affected people with suppressed immune systems, C. gattii appears to be mutating as it moves south. Newly reported C. gattii infections are affecting people with healthy immune systems and are causing more deaths than previous strains of the fungus. At this time, however, cryptococcosis is still a rare disease.
C. gattii can live in decaying organic matter, soil (especially soil contaminated with bird droppings), and trees, especially in coastal forests.
The risk of exposure goes up when soil or organic matter is disturbed. C. gattii reproduces by giving off spores that can settle in soil and on surfaces. These settled spores can become airborne. People can become infected when they breathe the spores in. Once inside the lungs, the spores can reproduce and spread throughout the body.
Symptoms from C. gattii infection can take between two to fourteen months to appear after exposure. Infection may cause a pneumonia-like illness, with shortness of breath, coughing, nausea, and fever. Another common form of C. gattii infection is central nervous system infection, such as meningoencephalitis. Symptoms may include fever, headache, or a change in mental status. Advanced disease can result in masses of fungal growth in the body.
C. gattii also infects other animals, including cats and dogs.
Animal symptoms include a runny nose, respiratory and nervous system problems, and lumps under the skin. There are no reports of the disease spreading from person to person, animal to animal, or from animals to humans. A person diagnosed with cryptococcosis is not contagious. Diagnosis of the disease involves the screening of body fluids or tissues. Antifungal drugs are used to treat the disease.
It would be prudent to avoid areas contaminated with pigeon or other bird droppings, especially if you have a suppressed immune system. Currently, the Centers for Disease Control and Prevention (CDC) has no formal recommendations for the prevention of C. gattii infection. Patients with signs and symptoms of infection are urged to see their physician.