Dr. Pastakia - tuberculosis - 4 questions

Question 1

Testing results in latent TB infection

Answer 1

TST: Positive
IGRA: Positive
Culture: Negative
Sputum smear: Negative

Question 2

Testing results in Subclinical TB disease

Answer 2

TST: Positive
IGRA: Positive
Culture: Intermittently positive
Sputum smear: Usually negative

Question 3

Testing results in Active TB disease

Answer 3

TST: Positive
IGRA: Positive
Culture: positive
Sputum smear: Positive or negative

Question 4

Multidrug resistant TB

Answer 4

TB strains that are resistant to RIF and INH

Question 5

Extensively drug-resistant TB

Answer 5

TB strains that are resistant to RIF and INH + at least one injectable agent (amikacin, kanamycin, or capreomycin) + any of the fluoroquinolones

Question 6

Spontaneous mutations develop as bacilli proliferate to >10^8

Answer 6

Rifampin - 10^-8
Isoniazid - 10^-6
pyrazinamide - 10^-6

resistance in TB is slightly different than other bacteria

Never use monotherapy as it can lead to growth of bacteria that is resistant to that monotherapy

Question 7

Treatment of drug susceptible TB

Answer 7

Rifapwnrine 1200mg + isoniazid 300mg + moxifloxacin 400mg + pyrazinamide 1000-2000mg once/day x 8 weeks

OR

Rifapwnrine 1200mg + isoniazid 300mg + moxifloxacin 400mg x 9 weeks