Cryptococcosis

Cryptococcosis Facts

Cryptococcosis is a disease caused by fungi from the genus Cryptococcus that infect humans and animals, usually by inhalation of the fungus, which results in lung infection that may spread to the brain, causing meningoencephalitis. The disease was first termed "Busse-Buschke disease" after the two individuals who first identified the fungus in 1894-1895. Cryptococcosis is found worldwide; the predominant way the disease is spread is through inhalation of fungus that is associated with many bird species, especially old pigeon feces and bat guano. Cryptococcus spp. is found in bird feces (mainly C. neoformans) throughout the world, but usually the birds themselves are not infected. Humans and animals usually get the infection from inhaling dust contaminated with bird feces and do not transmit cryptococcosis to other humans or animals. However, C. gattii is a type of Cryptococcus that is acquired by inhalation of airborne plant material (propagules or reproductive plant parts like a seed or spore). Until a few years ago, almost all C. gattii infections were associated with plants found in tropical and subtropical climates. This has changed since an outbreak has occurred in the Pacific Northwest (Vancouver Island, Washington, and Oregon).
The vast majority of cryptococcosis infections are caused by C. neoformans and C. gattii. Although there are over 50 Cryptococcus species, only a few other species rarely infect humans. In general, the people infected with C. neoformans usually have some defect in cell-mediated immunity (especially HIV/AIDS patients). However, C. gattii usually infects immunocompetent individuals (about 80% occur in "normal" individuals) but can infect immunocompromised people. Cryptococcosis is rarely transmitted directly into the skin (by laboratory accidents) and by organ transplants.