Summary:
Cryptococcus neoformans var. gattii, now known as Cryptococcus gattii, hit the headlines in 2002 in BC, with headlines starting "Killer fungus". Cryptococcosis is a fungal disease, usually presenting in humans as a subacute or chronic meningitis or as pneumonia. Early symptoms of meningitis include headache, nausea, staggering gait, dementia, irritability, confusion, and blurred vision. Fever and neck stiffness are often mild or absent. Infection often occurs in lungs (chest pain in 40% of lung infections, cough in 20%, shortness of breath, positive chest X-ray), but may occur in bone (4%), kidneys (rare), prostate (rare), liver (rare), heart (rare), or eyes (rare), and other symptoms may include weight loss, fever, and night sweats. The skin may show acne-like lesions, ulcers, or subcutaneous tumor-like masses (skin lesions occurring in 10% of cases). Untreated meningitis terminates fatally within several months (from two weeks to several years). Sporadic cases appear in many parts of the world, affecting mainly adults, and men twice as often as women. Transmission is not understood thoroughly but presumably occurs by inhalation: it does not appear to be contagious from person to person. The incubation period is unknown, probably about 2-9 months, and lung infection may precede meningitis by months or years. The frequency of Cryptococcus in the external environment and the rarity of disease suggests that most people have some resistance. At some point in their lives, most people are likely to inhale the fungal spores without developing an infection. Disease is more common when immunity is lowered: about 8% of untreated persons with AIDS in USA and Africa have developed cryptococcosis, usually by Cryptococcus neoformans var. neoformans. Infections with Cryptococcus gattii have been rare among AIDS patients and other immunocompromised patients, even in subtropical climates, where C. gattii infections occurs in previously healthy people. Infection occurs in 40 animals including cats, dogs, horses, cows, monkeys, ferrets, porpoises, and llamas, but infection does not appear to be transmitted to people from animals. C. neoformans var. neoformans can be isolated from pigeon droppings or soil. C. neoformans var. gatti can be isolated from plants or decaying plant material especially in tropical or subtropical areas. In Australia C. gatti is found in Eucalyptus. In 2002, on eastern Vancouver Island in BC, a cluster of cases of Cryptococcus gattii infection in humans led to the discovery of the fungus in the bark of Douglas fir, Grand Fir, Western Red-cedar, Garry Oak, and Red Alder. 52 cases were identified from 1999 to mid-2002, with one fatality, where previously the average had been 2-3 per year of the C. neoformans infections. The most common presentation was lung infection: 25 percent also had meningitis. The fungus grows well on appropriate media. Coculture of opposite mating types creates a transient diploid state called Filobasidiella neoformans var. neoformans for C. neoformans var. neoformans and Filobasidiella neoformans var. bacillispora for C. gattii. By 2010 the outbreak had expanded from Vancouver Island into neighboring regions including mainland BC, and WA and OR in the United States. The outbreak is caused predominantly by molecular type VGII/major. A novel genotype, VGIIc, has emerged in Oregon and is now a source of illness in the region. (combined sources).

Notes:
includes BC, WA, OR