TB Flashcards
What is the most common presentation of TB
pulmonary disease (arguably most concerning)
Which patient population is particularly vulnerable to death from TB
HIV patients
Is TB gram negative or gram +
Neither… “ghost cell”
*weakly positive sometimes seen on gram stain
What allows for TB to have such high infectivity
High lipid content of cell wall allows it to survive under extreme conditions
What are major risk factors for TB
Socio-economic factors
Immunosuppression
Occupation (mining/ construction)
How is TB spread
inhalation of infected aerosolized droplets
Who can spread TB
Only those with active TB
-spread via cough, speaking, or singing
What determines whether a person who comes in contact with TB can fight it off
Persons immune status
Genetic factors
Primary vs. secondary exposure
What are first line TB medications
Rifampin
Isoniazid
Pyrazinamide
Ethambutol
rifapentine
What are second line TB medications
Streptomycin
Amikacin
Levofloxacin
What meds are used with MDR-TB
Linezolid
Pretomanid
Bedaquiline
Delamanid
What type of organism is TB
alcohol and acid-fast bacillus
If a patient is prescribed isoniazid, what also needs to be prescribed
pyridine (Vitamin b-6)
What are the side effects of rifampin
orang discoloration of body fluids
What are the side effects of isoniazid
AST/ALT elevations, clinical hepatitis, peripheral neurotoxicity
What are the side effects of Pyrazinamide
Hepatotoxicity
polyarthralgias
acute gout
rash
photosensitive dermatitis
What is a major cause of TB becoming drug resistant
failure to complete full course of treatment
Where does primary TB usually settle in the lungs
middle portion (Ghon focus of primary TB)
What is the only form of TB that is contagious
pulmonary
What does Ghon focus TB do
enter latent phase
If a patient develops the active disease after the first TB exposure, what kind of disease do they have
Primary progressive TB
Active TB
What will be seen on CXR with primary TB
Middle lung zones but lacks marked tissue damage or cavitation
What are cavitation lesions in the lungs
Granuloma: an aggregation of multinucleate giant cells surrounding mycobacterium particles
What is the diagnostic histopathological hallmark of TB
Granulomatous
What causes the granuloma to look cheese-like
mycotic acid concentration in the cell walls
What is caveating necrosis
central area of eosinophilia
Where does most of TB in the US come from
untreated latent TB infections
What is secondary TB
People who develop TB after a long latency period
What will a CXR look like on secondary TB
lesions in lung apices and cavitation
What are symptoms of active TB
cough for a minimum of 3 weeks
pleuritic pain
hemoptysis
nocturnal sweating
no appetite
What is military TB
Pulmonary or systemic dissemination of tubercles in active disease
CXR: millet shaped lesions
What is disseminated TB
may also be seen in the spine, CNS or bowel
When is IGRA TB test preferred
If BCG vaccine has been revieved
Unable to make second TST appt.
What is high priority for TB treatment
Postive IGRA
positive TST >5mm & immunosuppressed, recent TB contact, fibrotic CXR changes
Positive TST >10mm & from endemic area, recent TB contact, kids<4y/o
What is the preferred TB test for children <5
PPD
What are the common latent TB treatment regimens
1) isoniazid + rifapentine 1/wk x3mo
2) Rifampin 1/day x4months
3)Isoniazid + rifampin 1/day x 3mo
What TB treatment have lower risk for hepatotoxicity
Shorterrifampin treatment
What are differentials. for TB
pneumonia
malignancy
non-TB mycobacterium
fungal infections
histoplasmosos
sarcoidosis
Who should NOT have RPT-MOX treatment regimen for TB
<12 y/o
<40kg
pregnant or breast feeding
prolonged QT syndrome
known/suspected drug resistance
What TB treatment is category A for pregnancy
isoniazid
