Pneumocystis carinii infection: diagnosis and pathogenesis.

The methods of diagnosis of Pneumocystis carinii infection are reviewed; a high index of suspicion of the disease, particularly in the immunodeficient patient, is stressed and the classic morphology of the organism is described. Discussed are the known immunologic features gleaned from clinical and pathologic data from the literature and the reported cases from the University of Minnesota Hospitals. The importance of the complete investigation of the immune status of every patient who develops pneumocystis infection is stressed.