[Tuberculous infection and pulmonary tuberculosis in adults]

A tuberculous infection is the result of inhalation of tubercle bacilli either in great numbers or in subjects with diminished immunity. Clinical tuberculosis will only occur in 10 per cent of subjects following a first infection (primary tuberculosis) or subsequently (secondary tuberculosis or by a reactivation of a tuberculous lesion). All the intrathoracic structures may be involved in isolation or in the case of extra thoracic tuberculosis eventually disseminated. The clinical manifestations are most often non-specific. The persistence of respiratory symptoms are nevertheless suggestive, above all in a subject belonging to a group at elevated risk of tuberculosis. The radiological aspects may be very suggestive of tuberculosis. The diagnosis of an infection is based on a study of the skin responses to tuberculin and those on tuberculosis on the evidence of the tubercle bacillus.