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Flashcards in Tuberculosis Deck (17):
1

What is the clinical presentation of TB?

Slow to resolve chest infection
Haemoptysis
Weight loss
CXR abnormalities

2

Does TB affect upper or lower lobes?

Tends to affect upper lobes

3

Why are mycobacteria bacilli considered to be alcohol and acid fast bacilli?

They retain dye even after exposure to acid and alcohol whereas other bacteria don't.

4

How does TB appear on a Ziehl-Neelsen (ZN) stain?

The mycobacteria appear as red dots. However, this does not give any indication of sensitivity or species.

5

How long does PCR testing for TB take?

1-2 hours

6

Why is PCR testing useful?

Fast
Gives some indication of species and sensitivity

7

Why is culture on Lowenstein-Jensen medium still important despite the slow growth time?

Best sensitivity to TB and gives information on antibiotic sensitivity.

8

What are the four drugs used to treat TB?

Rifampicin
Isozianid
Pyrazinamide
Ethambutol

9

Why must an eye test be given before administration of ethambutol?

May cause optic neuritis and blindness. Patients must report any difficulties or changes in vision after starting this drug. LFTs must also be checked.

10

Which drug causes yellow body fluids?

Rifampicin

11

Which two drugs are only taken for two months?

Pyrazinimide
Ethambutol

12

What is the only form of TB that is infectious?

Pulmonary

13

How is TB spread?

Airborne droplets containing TB

14

How is the spread of TB infection halted in the lungs?

Granuloma formation occurs through cell-mediated immunity by activated T-lymphocytes and macrophages
This gives rise to the latent disease - the disease may never become active

15

Why does latent TB become active?

Will not become activated unless there is a deficiency in cell-mediated immunity
Active disease presents when a host’s immune response cannot contain MTB replication

16

What is the definition of pulmonary TB?

Pulmonary TB is defined as active TB that is affecting any of the following:
Lungs
Pleural cavity
Mediastinal lymph nodes
Larynx

17

What does a "smear positive" test on a Zheil-Neehlson stain indicate?

Acid fast bacilli - patient is therefore potentially infectious and usually needs to be kept isolated