Tuberculosis

Question 1

Tb is an _________ pathogen

Answer 1

Airbourne

Question 2

What is the difference between Tb infection and disease?

Answer 2

Infection means the pathogen cannot be cleared and disease means symptoms are experienced

Question 3

Where will Tb normally be more prevalent in the lungs?

Answer 3

Apices

Question 4

Why does Tb usually grow preferentially in the lung apices?

Answer 4

Tb is an aerobic pathogen

In the apices of the lungs there is generally more ventilation than perfusion meaning inhaled aerobic pathogens will thrive most here

Question 5

Which type of bacteria is Tb?

Answer 5

Bacilli

Question 6

Why does Tb involve gramuloma formation?

Answer 6

Tb can enter alveoli and enter macrophages.

To respond, the body walls off the infected macrophages in a granuloma

Question 7

In people experiencing Tb symptoms, the body cannot hold the ________ within the _________

Answer 7

Infection

Granuloma

Question 8

How long can a granuloma hold the infection of Tb at bay?

Answer 8

It can vary from days to years

A Tb infection can remain “dormant” for many years

Question 9

Systemic symptoms of Tb include?

Answer 9

Weight loss, malaise and night sweats

Question 10

Respiratory symptoms of Tb include?

Answer 10

Cough, haemoptysis, breathlessness and upper zone crackles

Question 11

If lower lobes are infected with Tb, what does this suggest?

Answer 11

The infection occured through blood spread (sepsis)

Question 12

Tb does not just infect the lungs. What are some other complications of Tb?

Answer 12

• Meningeal Tb
• GI Tb
• Spinal Tb
• Cold abscesses
• Lymphadeopathy
• Pericardial - cardiac tamponade
• Renal
• Septic arthritis
• Adrenal - hypoadrenalism

Question 13

Which type of stan can detect Tb?

Answer 13

Ziehl-Neelson

Question 14

Describe the process by which Tb is identified through staining

Answer 14

• Tb is stained
• Alcohol and acid are added to remove the stain as far as possible
• The sample is washed with blue stain
• Any areas still red show presence of Tb which retains the original stain

Question 15

Tb can be identified by staining, how else can it be identified?

Answer 15

PCR (polymerase chain reaction)

Culturing

Question 16

The histology of Tb includes ___________ giant cell _________, _________ necrosis and potentially visible ___________

Answer 16

Multinucleate

Granulomas

Caseating

Mycobacteria

Question 17

What is the treatment for Tb?

Answer 17

6 month antibiotic course

• 2 months of
• Rifampicin
• Isoniazid
• Pyrazinamide
• Ethambutol

Followed by

• 4 months of
• Rifampicin
• Isoniazid

Question 18

What is a side effect of rifampicin?

Answer 18

It colours everything orange

(Bodily fluids, urine etc)

Metabolism is sped up in the liver leading to enhanced breakdown of steroid molecules (hormonal contraception) and opiates due to increased production of cytochrome enzymes

Question 19

What is a side effect of ethambutol?

Answer 19

It can cause optic neuritis

Question 20

Why does Tb treatent take so long?

Answer 20

There are two Tb populations:

1. The replcating bacilli
2. The trapped bacilli

Question 21

What are the different types of Tb resistance?

Answer 21

• Single agent
• Multi-drug resistance
• Extensive drug resistance (rifampicin, isoniazid and quinolone plus an injectable)

Question 22

What is latent Tb disease?

Answer 22

Symptomless Tb - Tb is in a dormant state

Question 23

How can it be determined that Tb is active?

Answer 23

• Symptoms present
• Cues through history
• X-rays (can show previous Tb by calcification)
• Culturing is positive

Question 24

What are two tests for previous Tb exposure?

Answer 24

1. Interferon gamma release
2. Mantoux (tuberculin test)

Tuberculin is a protein taken from mycobacteria which can prvoke a hypersensitivity reaction so it involves two visits, one for administering the tuberculin, another for measuring the response

Question 25

What is an alternative test to the tubercuin test that is more sensitive?

Answer 25

IGRA | (Interferon Gamma Release Assay)

Question 26

Why would latent Tb be treated?

Answer 26

There is a chance the patient may eventually develop symptoms 6 months of rifampicin or 3 months of rifampicin and isoniazid

Question 27

Tb often comes hand in hand with which other condition?

Answer 27

HIV

Question 28

What are some risk factors for pleural infection?

Answer 28

* Diabetes * Immunosupression from corticosteroids * Gastro-oesophageal reflux * Alcoholism * IV drug user

Question 29

What is a parapneumonic effusion?

Answer 29

A type of pleural effusion that arises as a result of pneumonia, lung abcess or bronchiectasis

Question 30

What are the three types of parapneumonic effusion?

Answer 30

1. Simple parapneumonic effusion 2. Complicated parapneumonic effusion 3. Empyema

Question 31

What is an empyema?

Answer 31

A collection of pus in the pleural space

Question 32

Large effusions will require _____ \_\_\_\_\_\_\_\_\_

Answer 32

Chest drainages

Question 33

What can be used to break down substances in parapneumonic effusions?

Answer 33

Fibrinolytics and DNAses

Question 34

What characteristics will a complicated effusion have?

Answer 34

* Ph \< 7.2 * Low glucose * Septations (divided into segments) * Loculations (containing many cavities) * +ve on gram stain