Pneumocystis carinii infection.

Over the past decade, P carinii has become an important cause of pneumonia in the compromised host. Progress has been made in clinical awareness of the organism, in methods of diagnosis, and in developing new forms of treatment. However, there is still a lack of basic knowledge about the biology, taxonomy, and epidemiology of P carinii; of specific host immune factors involved in the pathogenesis of the infection; and of a clinically reliable serologic test. With recent advances in P carinii research, progress hopefully will be made in these areas in the future.