The role of bronchoscopy in diagnosis of tuberculosis in patients with negative smear & culture

tuberculosis (TB) is a serious health problem in the world.in 1990 among 5.5 million population in the world,nearly 7.5 million new cases reported and 3 million  patients expired due to this problem.because early detectio of TB is very important ,we decided to evaluate the role of fiberoptic bronchoscopy(FOB) in detection of TB in patients with negative smear and negative culture of sputum.in this cross sectional study,377 patients with supspected TB  and negative smear & culture  were selected by convenience sampling method.in all patients fob & bronchoaveolar lavage(BAL) and in some patients transbronchial biopsy were performed.specimens were sent to one reference lab in the university Health center.among 377 cases,54.4% were male and 45.6% female.113 cases(30%) were positive for acid-fast bacilli(18% smear positive and 30% culture positive).although BAL study for TB showed 30% positive,transbronchial biopsy plus BAL,raised this figure to 50% in conclusion,it is recommended both FOB&BAL in suspected patients with negative smear and culture to be considered.