Pneumocystis Jirovecii

Abstract

Fungi in the genus Pneumocystis are extracellular, hostobligate, mostly host‐specific, and typically restricted to the lung tissues of mammals, although extrapulmonary manifestations have been reported. Pneumocystis species all appear to contain similar life cycle stages, although the clusters of organisms removed from the lungs of the different host species can vary in presentation and size. There is no consensus for a typing system for P. jirovecii . Serological assays to detect anti‐ P. jirovecii antibodies are useful for epidemiological studies, but not for diagnosis of Pneumocystis pneumonia . The microscopic demonstration of P. jirovecii in tissue and fluids by staining with Gomori methenamine silver or a rapid variant of the Wright‐Giemsa stain, by immunofluorescent assay, or by other stains such as Papanicolaou stain should be considered sufficient for diagnosis.