Mycobacterium Tuberculosis

Question 1

Where does secondary TB manifest in the lung? 3m

Answer 1

1. Apice
2. posterior upper lobes
3. or less likely superior segments of the lower lobes

Question 2

State the primary mode of TB transmission 1m

Answer 2

Aerosole 1-5um droplets

Question 3

Through what pathway does immunity develope and how long from transmission? 2m

Answer 3

Cell mediated immunity or hypersensitivity

Typically 2 weeks 15-18 days upto 10 weeks on occasions

Question 4

What percentage of patients cannot fight off an initial primary TB infection? 1m

Answer 4

5%

Immunocompromised i.e neutropeanic

Question 5

Which group is most vulnerable? 2

Answer 5

This is most common if the host
is immunocompromised because of immunosuppressive medications, alcoholism,
HIV/AIDS, or malignancy.

Data suggests that 5% of HIV patients have had TB

Question 6

Which type of TB can spread hematogenously? 1M

Answer 6

Miliary TB

Question 7

What percentage of patients will develope reactivated TB?

When is this most likely to occur? 2m

Answer 7

10% of individuals
with a normal immune system who have been infected with M. tuberculosis (and have not received treatment of latent tuberculosis infection to eradicate dormant organ-
isms) will develop active disease.

First 2 years

Question 8

State the likely healing process of sites of pre-existing TB ? 4m

Answer 8

1. Fibrosis
2. scarring
3. contracted tissue
4. calciuim deposite

Question 9

Patients with HIV = typical or atypical

Answer 9

atypical - therefore slow onset

Question 10

State the organs associate with hematogenouos TB spread and the nature of the TB diagnosis: 6m

Answer 10

1. Liver
2. kidneys
3. adrenal glands
4. bones
5. CNS
6. peritoneum

Miliary TB

Question 11

Describe latent TB infection? 2m

Answer 11

1. Bacilli established but unwell/progressed
2. also not contagious

Question 12

Describe likely clinical presentation of TB patients?

Answer 12

Systemic symtoms - Weight loss, fatigue, anorexia or loss of apetite

Similar to RTI

Abnormal CXR findings

Most people asymtomatic

Question 13

Describe clinical presentation of pulmonary involvement for TB? 4m

Answer 13

1. cought
2. sputum production
3. hemoptysis
4. CP
5. or asymtomatic

Question 14

What can the TB skin test not differentiate between? and benifit 3m

Answer 14

Those who have active TB and those with reactivate TB. But does identify people at high risk.

Question 15

Radiographic appearences of Reactivated TB?

Answer 15

1. Apical and posterior segments of upper lobes
2. infiltrates
3. cavities
4. nodules
5. scarring
6. contraction

Question 16

State what portion of patient will develope progressed primary TB?

Answer 16

5%

Question 17

Necrotic encapsulated areas have what percentage of a cance of developing in TB at a later stage? 1m

Answer 17

10%

Question 18

State the radiographic findings for TB immunocompetant patients? 5m

Answer 18

1. Heteregenous consolidation
2. ill-defined nodules possibly with linear fibronodular patterns 5%
3. Single/ multiple cavities 10-20%
4. Endobronchial spread with nodules distal to cavity 10-20%
5. Tuberculoma - large granuloma 5% inb reactivated TB

Question 19

State the radiographic appearences in immunocompromised TB patients? 3m

Answer 19

1. Hilar/ mediastinal lymphodenopathy(more common in primary TB)
2. pleural eff - unilateral 15-20% raise differential of TB even if no other findings in the lung
3. Milliary TB

Question 20

state complications associated with TB? 11m

Answer 20

Parenchymal

• ARDS*
• Lung destruction*
• aspergilioma*
• bronchiectasis*

vascular

• Thrombosis*
• Aneurysm*

pleural

• Empyema*
• pneumothorax*
• bronchopleural fistula*

Question 21

State the likelihood of cavitation in primary TB? 1M

Answer 21

10-30%

Question 22

State the likelihood of mediastinal lymphadenopathy in primary TB?

Answer 22

50%