Pneumocystic carinii pneumonia
Pneumocystis pneumonia (PCP) is a form of pneumonia caused by the yeast-like fungus, Pneumocystis jirovecii. This species of fungus is specific to humans. It has not been shown to infect other animals while other species of Pneumocystis that parasitize other animals (all of which are mammals) have not been shown to infect humans.[1] The causal agent was originally described as a protozoan and spelled P. jiroveci and prior to then was classified as a form of Pneumocystis carinii, a name still in common usage.[2][3] These names are discussed below. As a result, Pneumocystis pneumonia (PCP) has also been known as Pneumocystis jiroveci[i] pneumonia and as Pneumocystis carinii pneumonia, as is also explained below.[4][5][6] Confusion caused by the misapplication of the name P. carinii to all species of Pneumocystis may incorrectly suggest that the human pathogen could reside in other animals, including domesticated animals
