gattii

Cryptococcus gattii is a pathogenic yeast species in the genus Cryptococcus within the basidiomycete fungi. It is one of the agents that cause cryptococcosis in humans and animals and is distinguished from the related Cryptococcus neoformans by its ecological associations and disease patterns. C. gattii was historically associated with tropical and subtropical regions but has established reservoirs in temperate climates as well.

Environmental reservoirs include trees and decaying plant material. Inhalation of airborne yeast cells from the environment is the primary route of infection. Unlike C. neoformans, human-to-human transmission is not considered a driver of disease. After entering the lungs, the organism may remain localized or disseminate, particularly to the central nervous system.

Clinical manifestations range from asymptomatic or mild pulmonary disease to severe meningitis and focal brain lesions. In immunocompetent individuals, C. gattii infections can present with cryptococcomas and mass-like brain lesions that may resemble other causes of intracerebral disease. Symptoms commonly include headache, fever, neck stiffness, coughing, chest pain, and neurologic deficits.

Diagnosis relies on culture of cerebrospinal fluid or respiratory specimens, microscopy, and cryptococcal antigen testing in serum or CSF. Neuroimaging and lumbar puncture assist in assessing CNS involvement. Treatment typically begins with induction therapy using liposomal amphotericin B plus flucytosine for at least two weeks, followed by consolidation and maintenance with fluconazole, with therapy duration guided by site of infection and immune status. Monitoring for drug toxicity is important.

Public health notes include its status as a notable cause of cryptococcosis in immunocompetent hosts and its association with regional outbreaks, including in the Pacific Northwest. There is no vaccine, and management relies on antifungal therapy and clinical monitoring. Ongoing surveillance and research focus on environmental reservoirs and regional risk factors.