Infection 3 - Infection Model

Question 1

What are the four types of pathogen?

Answer 1

Eukaryotes:

• virus
• bacterium

Prokaryotes:

• fungus (yeast+mould)
• parasite (protozoa+helminth)

Question 2

What factors should be considered when diagnosing a person with an infection?

Answer 2

• age
• gender
• physiological state
• pathological state
• social factors
• ‘place’ (where they are currently, and where they recently have been)

Question 3

What are the seven main mechanisms of infection?

Answer 3

• contiguous (direct) spread
• inoculation
• haematogenous (spread through blood)
• ingestion
• inhalation
• vector (eg. mosquitos)
• vertical transmission

Question 4

Outline the stages of an infection leading to host damage

Answer 4

1) attachment of the pathogen
2) attachment leads to toxin production and interaction with host defences which both directly lead to host damage
3) interaction with host defences causes inflammation, which leads to host damage

Question 5

What three components make up a diagnosis of an infection?

Answer 5

History, examination and investigations

Question 6

True or false - a chronic infection always has a set outcome?

Answer 6

False - it stretches from cure to death, with intermediates of disability in varying intensity