export_bacterial lrt iii Flashcards
Mycobacteria structure
Lipid-rich cell walls
Acid-fast rods
Active vs. latent forms of TB epidemiology
Active is only 10% of infected people
TB has a 10% chance of converting from the latent form to the active form
Primary TB
Initially Mtb enters the body
Clearance can occur
Progress to active or latent TB
Latent TB
Macrophages form granulomas that wall the TB off because the Mtb evades destruction
Active TB
Typically in immunocompromised patients
Main concern with active TB
Rapidly dividing Mtb results in increased CMI activation, causing more caseous necrosis and inflammation
Active TB symptoms
Gradual onset
Weight loss
Night sweats
Cough (dry-severely productive)
Reactivation TB symptoms
Can be asymptomatic and infectious (TB escapes granulomas and spreads via exhalation)
Symptoms same as active
Diagnosis for latent TB
Ghon focus - lung lesion in the lung tissue, calcification
Ghon complex - lung lesion and calcification in an affected hilar node as well as lung tissue
Diagnose active TB
Focal infiltration with cavitation
Immuno-diagnosis of TB
Skin test
IFN-gamma release
Complication with skin test
If patient has received BCG vaccination
IFN-gamma required to diagnose
Treatment of TB
Isoniazid (INH)
Ethambutol
Pyrazinamide
Rifampin
Effect of isoniazid
Inhibits mycolic acid sythesis
Side-effects of isoniazid
Hepatoxicity
Must be observed taking medication correctly
