Primary progressive tuberculosis

Primary progressive Tuberculosis. Primary Tuberculosis is an infection of persons who have not had prior contact with the tubercle bacillus. In over 90% of normal adults the primary infection follows a self-limited course, because the cellular immune response is sufficient to control the multiplication of bacilli. Progressive primary tuberculosis occurs when the immune response fails to control multiplication of the tubercle bacilli. Infection takes this course in less than 10% of normal adults, but it is common in children under 5 years of age. This process is accompanied by caseous enlargement of the hilar lymph nodes, which may erode through the wall of the bronchus and discharge bacilli, thereby producing tuberculous pneumonia. Clinical manifestations are abrupt high fever (associated with progression to tuberculous pneumonia), pleurisy with effusion, and lymphadenitis.

Secondary (cavitary) tuberculosis usually results from reactivation of dormant, endogenous tubercle bacilli in a sensitized patient who has had previous contact with the tubercle bacillus leading to cavitatory TB.