Pulmonary mycobacterial diseases Flashcards
how are atypical or non TB mycobacteria infections classified?
rapid or slow growing mycobacteria
what are the rapid growing mycobacteria?
M. fortuitum complex
M. chelonae
M. absessus
what are the slow growing mycobacteria?
M. kansasii
M. marinum
MAC (avium, intracellulare)
progressive lung disease in non-TB pulmonary infections typically occurs in what type of patient?
underlying bronchiestasis or COPD
what are the two clinical forms of MAC? what are the demographics?
fibrocavitary - older male smokers with preexisting lung disease
fibronodular - nonsmoking women over 50 without underlying lung disease
what is the clinical presentation of non-TB mycobacterial infections?
usually typical or TB with cavitation 85-95%
what is required for diagnosis of non-TB mycobacteria?
bacteriologic confirmation
sputum (2 positive cultures)
BAL sample
lung or tissue biopsy positive AFB smears
positive culture from pleural effusion fluid
what are the three possible consequences of TB contraction?
- immediately cleared - no infection
- primary TB - immediate onset of active disease
- latent infection - possibility of reactivation
what % of the dormant population will develop a reactivation of TB infection?
5%
what % of individuals who contract TB eventually devleop infection?
30%
how does TB spread upon infection?
lymphatics - to regional lymph nodes
what is a Ghon complex on CXR?
unilateral lymphadenopathy suggestive of TB
what occurs if cell mediated immunity is inadequate? what is the result?
hematogenous dissemination - active disease and contagiousness
pulmonary symptoms occur in what % of cases of primary TB?
33% (1/3)
what are the radiographic findings of primary TB?
normal CXR
hilar adenopathy
perihilar infiltrates
effusion