USE OF INDUCED SPUTUM SPECIMENS FOR MICROBIOLOGIC DIAGNOSIS OF INFECTIONS DUE TO ORGANISMS OTHER THAN PNEUMOCYSTIS-CARINII

The optimal diagnostic approach to pneumonia provides a rapid microbio logic identification of pulmonary pathogens by the least invasive mean s. The technique of sputum induction has been useful in the evaluation of patients with Pneumocystis carinii or mycobacterial pneumonia. It is not known whether induced sputum samples are preferable for the det ection of pathogens other than P. carinii or mycobacteria. Microbiolog ic yields were evaluated from identically processed induced and conven tional sputum samples collected from 509 consecutive patients. No stat istically significant differences were found between the microbiologic yields of induced and spontaneous sputum samples. Bacterial pathogens were isolated in 19.6% of induced and 23.5% of routine specimens. Myc obacteria were cultured from 13.1% of routine and 9.4% of induced spec imens. Non-Candida albicans fungi grew from 24% of routine and 20% of induced specimens. The process of sputum induction with aerosolized hy pertonic saline did not alter either the purulence or the bacterial qu antitation of Gram-stained sputum specimens. Sputum induction has been useful for the cytologic diagnosis of malignancy, for the diagnosis o f pneumocystosis and tuberculosis, and in patients unable to spontaneo usly produce sputum samples. The use of induced sputum samples for the diagnosis of other infections may not be necessary when routine sputu m specimens are available.