TB

Question 1

Proportion worldwide infected with TB

Answer 1

10%

Question 2

Lifetime risk of TB infection progressing to disease

Answer 2

10% (50% in first year)

Question 3

% progression to disease in HIV-infected

Answer 3

10%/yr

Question 4

Active TB RFs

Answer 4

HIV, MN, DM, ETOH, active smoking, indoor air pollution

Question 5

sensitivity of ZN microscopy cf culture

Answer 5

50%

Question 6

Primary TB - % that develop clinical disease

Answer 6

5-7% in 2 years
5% in lifetime
90% asymptomatic

Question 7

Progressive primary TB

Answer 7

Haematogenous spread - miliary, meningeal

esp children, elderly, immunosuppressed

Question 8

Tuberculin >5mm positive

Answer 8

HIV+
Recent contacts of TB case
Fibrotic changes on CXR c/w old healed TB
Organ Tx / immunosuppressed

Question 9

Tuberculin >10mm positive

Answer 9

Residents/employees of high-risk congregate settings
Recent arrivals from high-prev countries
Mycobact lab personnel
Persons with clinical conditions putting them at high risk
IVDU
u4, children/adolescents exposed to high-risk adults

Question 10

RFs for developing TB disease

Answer 10

• Recent convertor
• PPD+ with active pulm lesion on CXR
• Immunosuppressed (CCSs, gastrectomy, silicosis, DM)
• Preg with cured cavitary lesion / TB sequelae that never received Rx

Question 11

Duration Rx with regimen lacking PZA

Answer 11

min 9 mths

Question 12

Duration Rx with regimen lacking RIF

Answer 12

min 12 mths ( - 18)

Question 13

Duration Rx with regimen lacking INH

Answer 13

12 mths still ok

Question 14

Indications for CCSs in TB

Answer 14

Meningitis (6 wks)
Pericarditis (11 wks)
Occular TB