Post-bronchoscopy sputum: improving the diagnostic yield in smear negative pulmonary TB.
ABSTRACT Patients with suspected active Pulmonary Tuberculosis (PTB) who are Acid-Fast Bacilli (AFB) smear negative or non-productive of sputum may undergo bronchoalveolar lavage. However, post-bronchoscopy sputum (PBS) sampling is not routine. The aim of this study was to establish the potential diagnostic value of PBS sampling.
A retrospective study of patients attending a London University hospital with microbiologically confirmed PTB between January 2004 and December 2010. Patients who were AFB smear negative or non-productive of sputum were eligible if sputum sampling was performed within 7 days of bronchoscopy.
Over the study period, 236 patients had microbiologically confirmed smear negative PTB of which 57 patients were eligible for the study. 15 patients (26.3%) were infected with HIV. 19 patients (33.3%) converted to AFB sputum smear positivity post-bronchoscopy and 5 patients (8.8%) were exclusively AFB sputum smear positive on PBS microscopy. Mycobacterium tuberculosis was cultured from the PBS of 43 patients (75.4%) and of these, 4 (7.0%) were exclusively PBS culture positive.
PBS analysis can provide a simple method of rapidly diagnosing pulmonary tuberculosis. In this cohort, M. tuberculosis culture yield was increased by 7% through PBS sampling. This study has important infection control implications with nearly one third of patients becoming more infectious after bronchoscopy.
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ABSTRACT: To assess the value of fiberoptic bronchoscopy and transbronchial biopsy for evaluating patients suspected of having tuberculosis, we reviewed the records of 56 patients (1974–1980). All patients (1) were clinically suspected of having active tuberculosis; (2) had an abnormality on chest roentgenogram consistent with tuberculosis; (3) had an absence of acid-fast bacilli on three sputum smears or an inability to produce sputum; (4) had undergone fiberoptic bronchoscopy and transbronchial biopsy. The evaluations included fiberoptic bronchoscopy with collection of bronchial washings and brushings, and transbronchial biopsy and postbronchoscopy sputum specimens. Thirteen patients subsequently underwent percutaneous needle aspiration and one underwent thoracotomy.Evaluations were diagnostic in 29 of the 56 patients (52 percent). Diagnoses were mycobacterial infection in 22 (39 percent) and other disease processes in seven (13 percent). Fiberoptic bronchoscopy and transbronchial biopsy provided a diagnosis when sputum cultures obtained before bronchoscopy were negative for Mycobacteria in 11 (20 percent) patients. Immediate diagnoses were made from microscopic specimens obtained from 11 of 23 (48 percent) fiberoptic bronchoscopy and transbronchial biopsy procedures on patients with previously undiagnosed mycobacterial infection. Transbronchial biopsy had the best yield for a microscopic diagnosis. On culture, bronchoscopy specimens had a lower yield (10 of 23 or 44 percent) than sputum specimens obtained before bronchoscopy (14 of 21 or 67 percent) probably due to the inhibition of mycobacterial growth by tetracaine. Of the patients in whom evaluation proved nondiagnostic, 17 of 27 were lost to follow-up; therefore, a definitive statement regarding the number of false negative evaluations is not possible.Fiberoptic bronchoscopy and transbronchial biopsy (FFB/TBB) is a useful procedure in evaluating patients with negative smears who are clinically suspected of having tuberculosis. It can improve the ability to document active tuberculosis, provide a sensitive means of making an immediate diagnosis, and uncover other disease processes presenting like tuberculosis.The American Journal of Medicine 07/1981; 70(6):1189-94. · 4.77 Impact Factor
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ABSTRACT: The value of the smear for acid-fast bacilli in predicting pulmonary tuberculosis is unclear in a setting where there is a high prevalence of Mycobacterium avium complex in respiratory specimens. To evaluate the impact of a high prevalence of M. avium complex on the predictive value of the acid-fast bacilli smear for tuberculosis, we reviewed findings on smears and results of cultures over a 3-year period at a hospital where M. avium complex is the predominant mycobacterial isolate. In this setting, the predictive value of the acid-fast bacilli smear for Mycobacterium tuberculosis was 92% for expectorated sputum specimens, 71% for induced sputum specimens, and 71% for bronchoalveolar lavage specimens. When multiple specimens collected from the same patient were excluded from the data base, the predictive values were 87%, 70%, and 71%, respectively. Smears of sputum samples were positive at the same rate for patients with tuberculosis who had AIDS and for patients with tuberculosis who did not have AIDS.Clinical Infectious Diseases 09/1994; 19(2):334-6. · 9.37 Impact Factor