Tuberculosis Flashcards
1
Q
What was the old name for TB?
A
Consumption
2
Q
Why does TB not stain well in gram stain?
A
It has a thick lipid covering
But occasionally it is weakly gram +
3
Q
How often does it divide?
What does this mean for tx?
A
It takes 20 hours to divide, as opposed to E.coli
Its resistant to antibiotics as antibiotics usually kill dividing cells
4
Q
TB antibiotics
A
Streptomycin was the first AB discovered to kill TB - it affects ribosomes so can kill non-dividing bacteria
–dont use this much anymore b/c a lot of toxicities
Isoniazid (INH) is go to drug
–acts on the cell wall and also induces NO that kills bacteria
5
Q
What puts you at risk for TB? (in terms of other contacts)
A
- -how close of contact you had
- -infectiousness of source
- -cavitary lesions worse than just smear positive
- -25-50% of household contacts will become infected
- -with AB, quickly become noninfectious
- -no risk by fomites, animals, etc
6
Q
What host factors put you as risk?
A
Substance abuse Malnutrition Malignancy, diabetes, gastric bypass HIV Steroids TNF inhibitors
7
Q
What environmental factors put you as risk?
A
Presence of household contacts Birth in a TB endemic area Crowded community with poor ventilation Living in prisión, homeless shelter, nursing home Low socioeconomic status
