TB

Question 1

What is the most common cause of TB in humans?

Answer 1

Mycobacterium tuberculosis

Question 2

What is the life cycle of TB

Answer 2

Exposure from droplets - 70% uninfected

5% have active TB, 95% in sealed off granulomas (Latent TB).

Question 3

What investigations are there for primary TB from sputum and what are the pros/cons?

Answer 3

Acid fast bacilli - Quick but doesn’t distinguish between mycobacterium.

Culture - Takes 4-6 weeks

Question 4

What investigations are there for primary TB not using sputum?

Answer 4

Bronchoscopy, pleural biopsy, mediastinoscopy

Question 5

When do you treat Latent TB

Answer 5

• immuncompromised etc
• Healthcar worker

Question 6

What are the symptoms and signs of primary TB?

Answer 6

TH1 response if symptomatic

Asymptomatic

night sweats

chest pain

cough

Erythema nodusum

pleural effusion

conjunctivitis

CXR - Pleural effusion, hilar lymphadenopathy, Brocks Syndrome

Question 7

What can cause post primary (Reactivation TB)

Answer 7

Age, DM, Cancer, HIV, CRF

Question 8

What are the symptoms of post primary TB?

Answer 8

Fever, night sweats, WL, cough, haemoptysis

Examination findings - may be normal, cachexia, lyphadenopathy, consolidation

Question 9

What is miliary TB?

Answer 9

TB in the bloodstream

Question 10

What is the treatment for pulmonary TB?

Answer 10

R.I.P.E All four for 2 months, then R.I for 4 months

Question 11

How do the treatments for pulmonary TB work?

Answer 11

• Rifiampicin - RNA inhibition, targets active and dormant. Causes orange tears and liver toxicity. upregulates p450
• Isoniazid - Cell wall disruption, targets active and dormant. Causes liver toxicity and peripheral neuropathy
• Pyrazinimide - Cell membrane disruption, active, liver toxicity
• Ethambutomol - Cell wall disruption, active, optic neuritis

Question 12

What is another cause of TB in humans, more commonly affecting animals?

Answer 12

Mycobaterium bovis

(Bovine TB)

Question 13

What is blood test for TB?

Answer 13

IGRA

Question 14

What is this?

Answer 14

Miliary TB

Question 15

What it this?

Answer 15

Ghon complex

Calcified granuloma

Question 16

What is atypical mycobaterium?

Answer 16

Show up on acid fast bacilli but is not infective

Question 17

What is Brocks Syndrome

Answer 17

Right middle lobe collapse secondary to hilar lymphadenopahy

Question 18

What should treatment be in a negative pressure room?

Answer 18

MDRTB

Question 19

What gives a positive mantoux test?

Answer 19

Active TB

Latent TB

BCG

Atypical

Question 20

What could give a false negative mantoux?

Answer 20

Extreme age

Chronic disease

Other vaccinations

Miliary TB

Lymphoid disorders

Question 21

What may be some examination findings of TB?

Answer 21

NOTHING

Cachexia

Wheeze

Signs of consolidation, clubbing

Question 22

What is a treatment principle of TB (location)

Answer 22

Community if possible

Contact tracing and notify

Question 23

how does tb get in the body

Answer 23

TH1 - macrophage

Question 24

What is this and why do you get it?

Answer 24

Erythema nodosum

Becuase of the hypersensitivity reaction

Question 25

What is the difference between primary, post primary and latent TB?

Answer 25

Primary - when someone first becomes infected (may show no symptoms)

Post primary - Reactivation and symptoms later

Latent - TB but no symptoms

Question 26

How is TB transmitted?

Answer 26

Air droplets

Question 27

What is the most common test and how does it work?

Answer 27

AFB - stains bacilli

Question 28

What do you give with isoniazid and how does it work?

Answer 28

Pyroxidine

Mycolic acid inhibitor