FA Mycobacteria Flashcards
PPD + means
current infection, past exposure, or BCG vaccinated
PPD - means
no infection or anergic (steroids, malnutrition, immunocompromise) and in sarcoidosis
What is a more specific test (have fewer false positives from BCG vaccine) than PPD for TB?
Interferon-gamma release assay (IGRA)
histology of TB
Caseating granuloma - central necrosis with multinucleate Langerhans giant cell
Infection with TB in a non immune host (usually child) –>
primary tuberculosis
primary TB is characterized by
Ghon complex = hilar nodes + Ghon focus (usually in mid zone of lung)
If primary TB heals by fibrosis –>
immunity and hypersensitivity –> Tuberculin +
If primary TB –> prorgressive lung disease (usu in HIV or malnutrition) –>
death (rare)
if primary TB –> military TB –>
death
if primary TB –> re allergic lymphatic or hematagenous dissemination –>
dominant tubercle bacille in several organs –> reactivation in adult live
Infection with TB in a partially immune hyper sensitized host (usually adult) –>
secondary TB (reinfection)
secondary TB presents as a
fibrocaseous cavitary lesion usually in upper lobes
what are the six places where extra pulmonary TB tends to present?
CNS (parenchymal TB or meningitis) Vertebral body (Pott dz) Lymphadenitis Renal GI Adrenals
What are the four big TB symptoms
- Fever
- Night sweats
- Weight loss
- Hemoptysis
What disease causes pulmonary TB like symptoms?
M Kansasii
