[Pneumocystosis is an actual infection].

Contemporary aspects ofthe problem ofdiseases caused by single-celled yeast fungi Pneumocystisjirovecii are examined. Pneumocystic infection affects children and adults with various manifestations of immunodeficiency, is a HIV-associated infection. Contemporary epidemiologic characteristics of this infection are presented, data on etiology, pathogenesis and clinical presentation ofpneumocystosis are provided, problems of laboratory diagnostics are elucidated. Morphologic, immunobiologic and molecular-genetic methods of detection of Pneumocystis jirovecii causative agent are described.