Tuberculosis Flashcards
Primary
Asym or mild flu, initial seeding in mid/lower lung. Reps in alveolar macrophages and apops them
Tubercle
lesion after primary infection = granuloma formation
Ghon complex
Formed as macrophages carry organism to nearby lymph leading to swelling and calcification
Latent
Some organism can remain viable leading to latent infection. When Tubercle contains bacilli but IR keeps it in check = not infectious
Detection
Detected by Mantoux skin test (TST) or blood for IFN-alpha release assay. QFT-G, QFT-GIT, T-spot
TB infection
Immunce can’t control infection. Systemic manifestations = low grade fever, anorexia, fatigue, night sweats, weight loss.
Bug
Mycobacterium Tuberculosis
Cause of increased rates
Aging population, increased travel, increased drug resistance, increased AIDs
Reactivated TB (Secondary)
Results from decreased T cell immunity, organisms reactivate in higher lung fields for increased oxygen levels, disease becomes contagious, sputum is acid fast, cavitate lesions.
Miliary TB
hematological dissemination results in lesions, hematagenous spread to other organs.
Extrapulmonary TB
More common since HIV. With lymphoadenopathy and neg TB test - CNS involved
Char
Acid Fast gram pos rod. Obligate aerobe and facultative intracell
Staining
Avraminarhodamine stain - sensitive but not spec
VFs
Catalase pos, Trehalose dimycolate (coord factor) inhibs leukocyte migration. Sulfatides- inhibits phagolysosome function. Disease is due to IR dmg.
Diag
Acid Fast Bacilli sputum, PPD, CXR = tubercules, ghon complexes, cavity lesions.
Lowstein J ensin culture
Susceptible = Niacin
Heat sensitive catalase production
