TB Flashcards
(40 cards)
What is BCG
Attenuated live vaccine from M. bovis
functional of BCG
decrease disseminated TB but not decrease pulmonary TB in children
effectiveness of BCG
decrease from 75% in old days, less effective when close to equator
cause of TB
M. Tuberculosis
others: bovis, africannum, microti, Canetti
non-tuberculosis mycobacteria
M avium complex
TB transmission
droplet nuclei containing tubercle bacilli
what is Ghon focus
calcified granuloma
what is primary TB
may cause military spread in immunocompromised or extreme age( contained within 3 wk)
what is post-primary TB
reaction with cavitation
site of TB infection
brain, larynx, LN, pleura, bone, lung, kidney, spine
finding on extra pulmonary tb
skipped lesion in potts disease
nodular appearance and military pattern
transmission of TB depends on
- infectiousness of person
- environment of exposure
- length of exposure
- virulence of tubercle bacilli
how to control transmission
isolation
effective treatment ASAP
3 fates after Tb infection
- spontaneous healing
- acute infection
- containment( 90%)
pathology of TB
caseous necrosis and cell mediated immunity with granuloma in cavitation
when will active TB develops?
when immune system unable to keep tubercle bacilli under control
when will active tb develop
soon after infection or many years
usually within 3-5 year
how many LTBI develop TB disease
10%
which type of TB is infectious
pulmonary TB not extrapulmonary TB
Risk factors to active TB
HIV, Steroid, TNF- inhibitor smoking, chemo, silicosis, organ transplantation, DM
How to treat active TB
4 mon(rifampicin, isoniazid, ethambutol, pyrazinamide) for intensive phase, and 4 mo (rifampicin and isoniazid) for maintenance phase
monoresistent TB
Resistant to any one TB treatment
polyresistent TB
at least any 2 TB ( not both isoniazid and rifampicin)
multidrug resistent TB
resistant to both isoniazid and rifampin