TB Flashcards
mycobacterium tuberculosis stains
gram stain- gram positive bacillus
Ziehl-Neelsen stain - “Acid-fast stain” due to lipid-rich cell wall; mycobacteria stain red
Obligate aerobe - takes up to 60 days to grow
latent TB spread infection?
labs show
no
positive blood test, negative chest xr
tb cough longer than___weeks
2-3 weeks
most healthy adults have which type of presentation of TB
children?
pulmonary
other tissues in the body- GI, lymph node, genitourinary, skeletal (potts disease)
IGRA
quantiferon
gold spot
this symptom indicative of TB
cervical lymph nodes that open and drain fluid
dx tb in children
CXR- 1/2 negative
Sputum culture- only in children >10
PPD- negative if coinfected with HIV
Gastric aspirate on 3 separate days
how many who have latent tb will turn active?
those with HIV?
10% over lifetime
5-10% per year
Treatment TB
4 drugsx 2 months
2 drugsx 4 months
rifampin + inh +pyrazinimide (PZA) + ethambutol (EMB)
then
rif+ inh
MDR-TB=
tx options
drug resistant tb (rif/inh)
Options include:
Quinolones: moxifloxacin, levofloxacin, gatifloxacin
AGs: streptomycin, capreomycin, kanamycin
Other drugs: PZA, cycloserine, ethionamide, PAS
Minimum of 4 drugs used usually for 12 months
xdr-tb means?
tx options?
extremely drug resistant (inh+rif+fluoroquinolone)
need injection- capreomycin, kanamycin, amikacin
TB drugs efficacy with ART
how to initiate both
if started at the same time what can happen?
more efficaceous when given together
start tb first, then initiate art after 2 weeks (and BY 8 weeks irrespective of cd4)
IRIS- huge inflammatory response
rifampin increases or decreases level of HIV drugs
decreases
preferred art tx for adults who are also being treated for TB
efavirennz (EFZ)
most widely used vaccine worldwide
efficacy for adults and children
bcg for tb
adults- 50%
pedi- BEST FOR PREVENTION OF SERIOUS FORMS OF TB
chest xray and sputum cultures in immunocompromised patients- what is result?
may be negative despite having TB
Testing for latent TB
First line? or?
PPD, IGRA for those who may not come back
IGRA preferred method of screening for?
if had bcg vaccine, poor rate of return
preferred method of screening children?
PPD <5 y/o
PPD positive results
> 5mm: HIV + (or IDU and unknown HIV), close contact of active case, fibrotic CXR lesions, persons on steroids, transplant patients
> 10mm: high prevalence country, IDU and HIV neg, medically underserved, long-term care facilities, certain medical conditions
> 15mm: no increased risk
PPD interpretation for those who received vaccine for those that didnt?
same per cdc
treatment latent TB
pregnant?
rifampin x 9 months
inh x 4 months
inhx 9 months for pregnancy, may delay
immune reconstitution syndrome (IRIS)
definition
can occur up to ____ months
consider adding what drug?
paradoxical clinical deterioration after starting combination ART, resulting from inflammation directed at underlying infections that are unmasked as the immune system improves
can occur up to 6 months
prednisone
