Clin Med: TB Flashcards
Tuberculosis is caused by
mycobacterium tuberculosis
Major risk factors for TB
socio-economic factors
immunosuppression (HIV and DM m/c)
occupational: mining, construction workers, pneumoconiosis (silicosis)
Transmission of TB
only persons with active TB can spread TB bacteria to others
usually through cough, speaking or singing
Important to know about TB treatment
requires close follow up and monitoring for side effects
TB disease process
cavitation lesions in the lungs
granuloma - aggregation of multinucleated giant cells surrounding mycobacterium particle
Granulomatous cavitation is the diagnostic histopathological hallmark of TB
How to test for TB
mantoux tuberculin skin test (TST or PPD)
interferon-gamma release assay (IGRA)
Pts with a positive test should have at min
CXR, consider ID consult and additional testing
TB on CXR
Granulomatous cavitations usually in the upper apices
People who develop TB after a long period of latency =
secondary TB
No sx, does not feel sick, positive TST or IGRA =
latent TB
Both latent and active TB needs to be ______
treated
Miliary TB is
pulmonary or systemic dissemination of tubercles in active disease (millet shaped lesions on CXR)
Post-exposure to know TB disease work-up
TB symptom screen
TB testing:
if previous neg TB test:
- test immediately and again 8-10 wks later
if previous positive TB test:
- do not test, screen for sxs
Neither the PPD or interferon blood test does not tell you if
it is active or latent
Ssx of active TB
cough 3+ wks
pleuritic CP
hemoptysis
are all most common
