Pneumocystis carinii pneumonia in the United States. Epidemiologic, diagnostic, and clinical features.

Abstract

Analysis of 194 patients with confirmed Pneumocystis carinii pneumonia in the United States over a 3-year period revealed that P. carinii pneumonia occurred almost exclusively in the immunosuppressed host who had a serious underlying disease. The epidemiologic features of pneumocystis pneumonia primarily reflected those of the underlying disease. P. carinii was identified antermortem in 81% of the cases usually by biopsy or needle aspiration of the lung, procedures associated with considerable morbidity and morbidity and mortality. Laboratory identification of P. carinii was usually accurate, but errors resulting from fault staining tecnique occurred. Most patients had been ill less than 2 weeks with bilateral diffuse interstitial pneumonia. Leukopenia (white blood cell count less than or equal to 3,00/mm3) and probably severe hypoxia were negative prognostic factors. Although treatment with pentamidine was effective, the drug frequently cased adverse reactions, particularly impaired renal function, when given with other nephrotoxic agents.