Comparison of induced versus expectorated sputum for diagnosis of pulmonary tuberculosis by acid-fast smear.
OBJECTIVE
To evaluate the sensitivity of induced versus expectorated sputum for the diagnosis of pulmonary tuberculosis by acid-fast smear.


METHODS
We performed a retrospective review of data on patients with cultures from respiratory secretions that were positive for Mycobacterium tuberculosis. We analyzed data on the 114 patients with positive cultures during a 4-year period in an urban tertiary care academic medical center.


RESULTS
Sputum samples had been obtained for 103 of the 114 patients with cultures positive for tuberculosis. Forty-four of the 114 patients were HIV seropositive. Overall 33 of 79 patients (42%) had positive acid-fast smears of expectorated sputum, and 6 of 24 (25%) had positive smears of induced sputum (p = 0.21). When data were analyzed for subgroups by HIV serostatus, there was no significant difference in the results. Estimated cost of sputum induction for 1 year was approximately $45,000.


CONCLUSIONS
We found sputum induction to be costly, and induced sputum offered no advantage over routine expectorated sputum for the diagnosis of pulmonary tuberculosis.
Merrick
S T
ST
Division of Infectious Disease, New York Hospital-Cornell Medical Center, NY 10021, USA.
Sepkowitz
K A
KA
Walsh
J
J
Damson
L
L
McKinley
P
P
Jacobs
J L
JL
D004396:Coloring Agents; D003581:Cytodiagnosis / Q000191:economics; D018023:HIV Seronegativity; D006679:HIV Seropositivity; D006786:Hospitals, Urban; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D009519:New York City; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D004396:Coloring Agents