Usefulness of bronchoscopic aspirate in sputum negative acid fast bacilli cases in the diagnosis of tuberculosis - A study of 30 cases

The confirming diagnosis for tuberculosis as recommended by World Health Organization is by detecting the Acid Fast Bacilli bacteriologically in the respiratory specimens. In certain cases, where there is a strong clinical and radiological suspicion for tuberculosis and with repeated sputum samples showing negativity for AFB, bronchoscopic study with bronchial washings for the detection of AFB increases the yield of true positive cases. The main is to ascertain the usefulness of bronchial wash AFB smears in sputum smear AFB negative cases with a strong clinical suspicion of tuberculosis. In this study, we selected 30 patients with a clinical suspicion of tuberculosis and 3 consecutive morning sputum samples was collected from each patient and stained with Zeihl Neelson stain for AFB detection. They were further subjected for bronchoscopic study with bronchial washing and AFB smears from such samples was analyzed. In results out of the total 30 cases, all the sputum samples were smear AFB negative. The bronchial washing AFB from the same set of cases showed positivity in 37% of cases. In conclusion thus, bronchoscopic examination with bronchial wash specimen is an essential requirement for respiratory work-up for early diagnosis of tuberculosis.