Lecture 11 Tb Flashcards
(23 cards)
Tb patients slowly waste away, hence the name ______
consumption
tb has a thick ____ covering that prevents staining by usual gram stains. some time it stains weakly gram ___
lipid;
positive
why is Tb more resistant to antibiotics?
divides very slowly, most Abs kill dividing bacteria
____ was the first Ab discovered to kill Tb because it affects ribosomes.
streptomycin
____ acts on the Tb cell wall and induces nitric oxide that kills bacteria
Isoniazid (INH)
____ lesions are more infectious than just smear positive infections
cavitary
infection is most likely to produce disease in _____ and the ____
infants, elderly
also 15-25 year olds
most common presentation of primary infection? What part of the lung is it seen in?
asymptomatic;
typically lower lung (ie lower part of the middle lobe)
what is usually the only evidence of a primary Tb infection?
positive PPD
bacteremic tb is called _____. do most patients after primary infection progress to more symptoms, or do most become asymptomatic?
milliary tb;
most become asymptomatic-latent Tb
In 5-10% of patients with latent Tb, it will become active again. this is called ____ tb.
reactivation
where does reactivation tb typically present in the lung? Why? what are the usual symptoms?
upper lobes, due to higher O2 tension;
fever, night sweats, hemoptysis, weight loss (classic Tb symptoms)
____ lesions on CXR are common in patients with reactivation Tb
cavitary
extra-pulmonary tb in the cervical lymph nodes is called _____. Tb in the spine is called ____.
scrofula; pott’s disease
The PPD is due to a _____ ____ immune response. It is measured based on ___ of the indurated skin
cell mediated;
diameter
false positive PPDs may be seen in patients with _____ or other mycobacterial infection. False negatives may occur in those with advanced ____, immunosuppresive therapy, or those with ____ ____
previous BCG vaccination;
HIV; active disease
2 other tests for latent infection:
do those with previous BCG vaccination react ?
T-spot; Quantiferon TB (measures release of IFN gamma);
nope
what is the gold standard for diagnosis of active disease?
culture; it takes 3-6 weeks
how many sputum smears for Acid Fast Bacteria are needed to diagnose or rule out Tb?
3 smears, over 8 hours apart
treatment of latent Tb:
Isoniazid (INH) for 9 months
toxicity of INH?
what to include to prevent side effects?
neuropathy, hepatotoxicity;
include vitamin B6 to prevent neuropathy
Standard care of treatment for active disease:
_____ for 2 months, check _____. then 4 months of _____
rifampin, isoniazid, pyrazinamide, ethambutol (RIPE);
sensitivity;
Rifampin, INH
____ is also effective in treating Tb.
fluorquinolones
