Bacteriologic diagnosis of extrapulmonary tuberculosis in a general hospital

: In a study performed in a general hospital within a period of 19 months, a total of 233 specimens of extrapulmonary origin and 543 lung secretions were tested for mycobacteria. The biopsy and punction fluid specimens were cultured without previous decontaminating treatment in Lowenstein Jensen, Stonebrink, Middlebrook 7H9, 7H10, 7H11 media and inoculated into guinea pigs (Table 1). Urine and lung secretion specimens were decontaminated and cultured in Lowenstein Jensen and Stonebrink media. No inoculation into guinea pigs was performed with these samples. The percentages of positivity by culture were: 11.2% for all extrapulmonary specimens (15% excluding 66 urine samples) and 22.5% for the lung secretions. Positive results were obtained in direct smear examinations in 82% of all positive-culture lung secretions and in 8% of the extrapulmonary specimens. Inoculation into guinea pigs gave less positive results than cultures. On the basis of the present study, it is recommended to culture every extrapulmonary specimens for mycobacteria. These samples should be processed immediately after collection and, if possible, without previous decontamination to assure the best test sensitivity. Eight percent of the strains obtained from extrapulmonary specimens were typed as M. bovis.