[Diagnosing pulmonary tuberculosis].

Unexplained cough for more than 2 - 3 weeks or patients considered to be at high risk for tuberculosis (TB) should be investigated in a timely manner: Chest radiography and 3 sputum examinations for detection acid-fast bacilli and TB cultures are essential first diagnostic steps. Pending sputum results an antibiotic trial (avoiding fluorochinolones) is warranted and if symptoms do not resolve and the diagnosis remains unclear then additional investigations are required to confirm or rule out pulmonary tuberculosis: sputum provocation by inhalation of hypertonic saline or alternatively bronchoscopy may provide samples to confirm TB or lead to an alternative diagnosis. Immunologic and molecular tests are useful in specific situations to identify previous contact with specific mycobacteria or identify drug-resistant strains. Prompt diagnosis and treatment are important epidemiologic measures to prevent transmission of mycobacteria to contacts including the medical personnel. Isolation measures take into account the transmission by aerosol and the viability of the mycobacteria and specific criteria need to be met before these precautions can be abandoned.