· Infection occurs when a person inhales droplet nuclei containing tubercle bacilli that reach the alveoli of the lungs.
· These tubercle bacilli are ingested by alveolar macrophages; the majority of these bacilli are destroyed or inhibited.
· A small number may multiply intracellularly and are released when the macrophages die.
· If alive, these bacilli may spread by way of lymphatic channels or through the bloodstream to more distant tissues and organs (including areas of the body in which TB disease is most likely to develop: regional lymph nodes, apex of the lung, kidneys, brain, and bone)
· This process of dissemination primes the immune system for a systemic response
· Within 2 to 8 weeks, special immune cells called macrophages ingest and surround the tubercle bacilli. The cells form a barrier shell, called a granuloma, that keeps the bacilli contained and under control
· If the immune system cannot keep the tubercle bacilli under control, the bacilli begin to multiply rapidly (TB disease).
· This process can occur in different areas in the body, such as the lungs, kidneys, brain, or bone
References
Wells BG, DiPiro J, Schwinghammer T (2013), Pharmacotherapy Handbook (6th Ed). New York, NY: McGraw-Hill.
DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey ML, (2008): Pharmacotherapy: A Pathophysiologic Approach (7th ed): New York, NY: McGraw-Hill.
Katz M D., Matthias KR., Chisholm-Burns M A., Pharmacotherapy(2011) Principles & Practice Study Guide: A Case-Based Care Plan Approach: New York, NY: McGraw-Hill.
Schwinghammer TL, Koehler JM (2009) Pharmacotherapy Casebook: A Patient-Focused Approach (7th ed): New York, NY: McGraw-Hill.