Pathology of Infectious Disease

Question 1

Name the 5 different classes of infectious agents:

Answer 1

1) Bacteria
2) Viruses
3) Fungi (including yeast)
4) Parasites
5) Prions

Question 2

How do organisms cause disease and give an example of each?

Answer 2

1) Live in any tissue (e.g. Staph Aureus)
2) Live in only a few types of tissue (e.g. Influenza)
3) Release products that damage widely (e.g. E.coli)
4) Release products that damage certain tissues (e.g. C.diff)

Question 3

How do bacterias cause damage to tissues?

Answer 3

Releasing:

1) Aggressins
2) Non-toxic material (which enhances the survival or the organism)

Question 4

Give 3 examples of non-toxic materials released by bacteria that damage the tissue?

Answer 4

1) Coagulase - promotes blood clotting
2) Streptokinase - promotes the activation of plasmingon to reduce blood clotting
3) Collagenase - breaks down collagen

Question 5

How do viruses cause damage to tissues?

Answer 5

1) Direct cytotoxic effects
2) Initiate immune reactions
3) Incorporate their viral DNA into the host’s DNA

Question 6

Give an example of a fungal infection and what it can cause?

Answer 6

Aspergillus sp.

This can colonise the airways to cause asthma

Question 7

Give an example of a yeast infection and what it can cause:

Answer 7

Candida Albicans.
Local - thrust
Systemic - immunosupressed

Question 8

What are the 4 different types of parasites?

Answer 8

1) Protazoa
2) Trematodes (flukes)
3) Nematodes (roundworms)
4) Cestodes (flatworms and tapeworms)

Question 9

Define prions:

Answer 9

Infectious particles with no DNA and RNA

Question 10

What is sepsis:

Answer 10

An overwhelming systemic response to an infection

Question 11

What are the 3 general signs of sepsis?

Answer 11

Temp: Below 36 or above 38
HR: Higher than 90 beats a min
Resp rate: higher than 20 beast a min

Question 12

What are the 6 severe signs of sepsis?

Answer 12

1) Decreased urine output
2) Decreased platelet count
3) Changed mental status
4) Abnormal pain
5) Abnormal heart pumping
6) Difficulty breathing

Question 13

What are the 4 common causes of sepsis?

Answer 13

1) Pneumonia
2) Bacteriaemia (blood infection)
3) Abdominal infection
4) Kidney infection

Question 14

What are the 4 defences that sepsis interferes with?

Answer 14

1) Cough reflex
2) Cilia
3) Pulmonary Oedema
4) Bronchial obstruction

Question 15

What problems can arise for patients undertaking sepsis treatment?

Answer 15

It is not uncommon that when people are being treated for sepsis they can pick up other infections