Unit 3- TB

Question 1

Factors that increase risk of TB include:

Answer 1

Foreign-born minorities

lower socioeconomic status and crowded housing

HIV

Multi-drug resistance

weak immunity

child <5

Question 2

T or F: TB spreads by airborne

Answer 2

FALSE

Spreads by droplet

Question 3

When TB is in miliary

Answer 3

bacilli spread to all parts of bod, rare but FATAL if UNTX

Question 4

When TB in CNS

Answer 4

occurs as meningitis

Question 5

When TB occurs outside the lungs

Answer 5

usually NOT INFECTIOUS, unless concomitant pulm disease, extrapulmonary disease of oral cavity or larynx, or with open site

Question 6

MDR (multi drug resistant) TB:

Answer 6

caused by bacteria resistant to best TB drugs isoniazid and rifampin

Question 7

XDR (extensively drug resistant) TB

Answer 7

caused by organisms resistant to isoniazid and rifampin, plus fluoroquinolones and >=1 of the 3 injectable second-line drugs

Question 8

Latent TB infection

Answer 8

granulomas may persist

2-8 weeks after infection: LTBI can be detected via TST or interferon-gamma release assay

Immune system is usually able to stop the multiplication of bacilli

Question 9

TB disease

Answer 9

granulmonas break down>bacilli escape>multiple>TB disease

can occur soon after infection or years later

Positive M. tb cultures confirms dx

Question 10

Can a person with LTBI spread the TB bacteria to others

Answer 10

NO

small amount of TB bacteria in the body that are alive but inactive

Does NOT feel sick but may become sick

Question 11

Which of the following is true in a person with LTBI:

a. CXR is normal
b. Sputum smear and cultures are negative
c. Should be tx with 4 different medications
d. Does not require isolation
e. Is considered a TB case

Answer 11

a, b, d

should consider tx to prevent TB disease

Question 12

Methods for detecting TB

Answer 12

Mantoux tuberculin skin test (TST)

IGAs: quantiferon-TB gold in-tube

T-spot TB

These tests DOONT exclude LTBI or TB disease

Question 13

Mantoux tuberculin skin test (TST)

Answer 13

purified protein derivative (PPD)

Takes 2-8 weeks after exposure and infection for immune system react to PPD

Reading in 48-72 hours

Question 14

PPD

Answer 14

0.1mL to produce 6-10m diameter

read 48-72 hr after

> =5 positive in: HIV, recent contact of TB, persons with fibrotic changes on CXR, organ transplant

> =10: travels to high prevalence, injection drug users, high-risk congregate setting, mycobacteriology lab personnel, persons w/ increase risk for progressing, child <5

> =15: person with no known risk factors for TB

Question 15

Interferon gamma release assay (IGRAs) work by

Answer 15

detecting infection by measuring immune response in blood

CANNOT detect between TB and LTBI

CAN be used as surveillance/screening

Question 16

IGRAs should not be used in children less than?

Answer 16

5

unless used in conjunction with TST

Question 17

Sx of pulm TB

Answer 17

prolonged cough (3weeks)
hemoptysis 
chest pain
loss or apetite
unexplained weight loss
night sweats
fever
fatigue

Question 18

Sx of possible extrapulm TB

Answer 18

Hematuria (TB of kidney)
H/A
Confusion (meningits)
Back pain (TB spine)
Hoarseness (TB larynx)
Loss of appetite
unexplained weight loss
night sweats
fever
fatigue

Question 19

T or F: CXR can confirm TB

Answer 19

FALSE

posterior/anterior view is standard

HIV pt may have typical appearance

Question 20

What is used for bacteriologic exam of speciments

Answer 20

AFB smear
NAA testing
Culture and identification
Drug-susceptibility

*sputum culture
collect at least 3, at 8-24 hour intervals, at least 1 in the morning

Question 21

Smear examination of specimen

Answer 21

quickest and easiest procedure

provides preliminary dx

Question 22

Direct detection using nucleic acid amplificaion (NAA)

Answer 22

test rapid via DNA and RNA

Earlier lab confirmation, earlier resp isolation and tx, improved pt outcomes

Perform at least 1 on each suspect

single negative does not exclude TB

Question 23

What is the gold standard for confirming dx

Answer 23

CULTURE

results 4-14 days

Question 24

Who is a candidate for LTBI?

a. high-risk with + IGRA or TST of >5
b. High-risk with +IGRA or TST >10
c. persons with conditions that inrease risk
d. low-risk persons with + IGRA and TST >15
e. all of the above

Answer 24

E. All of the above

Question 25

Isoniazid (INH)

Answer 25

LTBI tx
9 mo regimen

effective for HIV
Given 2/week via DOT

Preferred for child 2-11

DOT: pt takes med in front of provider

6month regimen acceptable
-not recommended for children, immunosuppressed, previous xray confirm

Question 26

Adverse reaction to INH

Answer 26

Peripheral neuropathy: give Vit B6 is has risk fx

fatal hepatitis: prego/postpartum at increase risk

elevated liver enzyme dc if enzymes exceed 3x normal with sx, or 5x upper limit with no sx

Question 27

INH-rifapentine (RPT) regiment

Answer 27

INH and RPT given in 12 weekly doses under DOT

healthy people >=12 w/ recent contact w/ TB

shorter tx time

NOT recommended <2, HIV person on ART drugs
prego
monitored monthly

Question 28

Recommendation Against the RIF / PZA Regimen

Answer 28

LTBI regimen if 2 months of RIF/PZA is no longer recommended owing to severe liver injury

PZA should NOT be offered to LTBI but should continue to be included in multidrug regimen

Question 29

Rifampin (RIF)

Answer 29

Alt to INH is 4 months daily RIF: 120 doses w/in 6 mo

should NOT be used in HIV persons being tx w/ ART

Can use if RIF cannot be used

Question 30

LBTI Treatment Regimens for Specific Situations

Answer 30

Prego or breast feeding

-9 mo of INH daily or twice/week GIVE w/ Vt b6