An Infection Model

Question 1

What is the model of infection?

Answer 1

The pathogen infects the patient via a specific mechanism of action. This leads to an infection which leads to management which leads to an outcome.

Question 2

What types of pathogens are there?

Answer 2

• Viruses
• Bacerium
• Fungus - Yeast (unicellular) and mould (multicellular)
• Parasite - Protazoa (unicellular) and Helminth / worm (multicellular).

Question 3

What factors influence if a patient gets an infection?

Answer 3

Person

• age - chickenpox affects adults much worse than children
• gender - UTIs are more common in women.
• physiological state - the hormonal changes during pregnancy can alter the pH and make women more likely to get thrush.
• pathological state - co-morbidities eg if you’ve got diabetes you’re more likely to get E. coli
• social factors - heart valves can get staph aureus in IV drug users because the needle takes the bacteria into the blood. Or the more sexual partners you have the more liekly you are to get an STI.

Time

• calendar time - flu is more common in the winter
• relative time - Time taken to incubate the disease eg chickenpox infects others in about 2 weeks.

Place

• current - Where you live
• recent - any holidays recently been on

Question 4

What are the mechanism of infection?

Answer 4

• Contiguous (direct) spread
• Inoculation
• Haematogenous
• Ingestion
• Inhalation
• Vector
• Vertical transmission

Question 5

How does an infection work (Vaguely)?

Answer 5

Question 6

How do you manage an infection?

Answer 6

• History
• Examination
• Investigation

This will get a diagnosis

• Treatment: specific and supportive
• Infection prevention: inc. in the hospital and the community.

Question 7

What key questions need to be asked to make the diagnosis?

Answer 7

Where is the infection?

What is the infection?

(It is not always necessary or possible to identify the specific organism causing the illness (microbiological diagnosis) - if so, just treat with set procedure)

Question 8

What specific treatment can we give a patient who has an infection?

Answer 8

• Anti-microbials
  
  • broad spec
  • specific.
• Surgery inc:
  
  • drainage
  • debridement (removing any tissue that is infected),
  • dead space removal.

Question 9

What supportive treatment can we give to patients with an infection?

Answer 9

Symptom relief - e.g. analgesics

Physiological restoration - e.g get pH back to normal.

Question 10

Who do we have to prevent infection towards? How?

Answer 10

-Other patients

-Staff

-Other contacts.

• Alcohol gel to prevent bacteria in wound.
• Depends on type of infection eg if C dif. Gloves, gowns.
• Mask FFP2 / FFP3

Question 11

What could the outcome of an infection be?

Answer 11

• Cure
• Chronic infection e.g. HIV
• +/- disability
• Death