Atypical mycobacteria in a tuberculosis hospital.

Cultures from 80 out of 1667 patients (4.8%) admitted consecutively to a tuberculosis hospital grew atypical mycobacteria. With four strict criteria it was concluded that the mycobacteria isolated were the cause of the disease in 47 of these patients. The majority of these organisms were resistant to most, and in seven cases to all, of the antituberculous drugs. Ten patients responded poorly to treatment and 14 patients (30%) died, 8 of these from uncontrollable pulmonary infection with the atypical organisms. It is suggested that a recent, simplified classification of mycobacteria proposed by Runyon be adopted.