Post-bronchoscopy sputum: improving the diagnostic yield in smear negative pulmonary TB

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Microbiology

Background:

• Bronchoalveolar lavage is used for suspected active Pulmonary Tuberculosis (PTB) in smear-negative or non-productive patients.
• Post-bronchoscopy sputum (PBS) sampling is not routinely performed.
• This study aimed to evaluate the diagnostic value of PBS sampling.

Purpose of the Study:

• To establish the potential diagnostic value of post-bronchoscopy sputum (PBS) sampling.
• To assess the utility of PBS in patients with suspected active pulmonary tuberculosis (PTB).

Main Methods:

• Retrospective study of microbiologically confirmed PTB patients (January 2004 - December 2010).
• Included AFB smear-negative or non-productive sputum patients undergoing bronchoscopy.
• PBS samples collected within 7 days post-bronchoscopy.

Main Results:

• 19 patients (33.3%) converted to AFB sputum smear positivity post-bronchoscopy.
• 5 patients (8.8%) were exclusively AFB sputum smear positive on PBS microscopy.
• Mycobacterium tuberculosis was cultured from PBS in 75.4% of patients, with 7.0% exclusively positive.

Conclusions:

• PBS analysis is a simple, rapid method for diagnosing pulmonary tuberculosis.
• PBS sampling increased M. tuberculosis culture yield by 7% in this cohort.
• Nearly one-third of patients became more infectious post-bronchoscopy, highlighting infection control importance.