An Infection Model

Question 1

What does an infection model allow for?

Answer 1

A simplistic look at the progress of most infections

Question 2

What does an infection model show?

Answer 2

How someone acquires an infection and what happens if they get one

Question 3

What is the infection model?

Answer 3

The interaction between pathogen and patient leads to infection.
Infection → management → Outcome

Question 4

What are the classes of pathogens causing disease?

Answer 4

Virus
Bacterium
Fungus
Parasite

Question 5

What are the classes of fungi?

Answer 5

Yeast

Moulds

Question 6

What are the classes of parasites?

Answer 6

Protozoa

Helminth

Question 7

What is the type and severity of an infection often influenced by?

Answer 7

Specific characteristics concerning the patient and their lifestyle

Question 8

What person factors can influence the outcome of infection?

Answer 8

Age
Gender
Physiological state
Pathological state
Social factors

Question 9

Why does age influence the type or severity of infection?

Answer 9

As age changes, so does the risk of acquiring particular infections

Question 10

Give an example of age changing the risk of acquiring particular infections

Answer 10

Newborns are prone to developing meningitis infections from E. Coli
At 3 months - 3 years, they are more likely to develop streptococci meningitis
There is increased risk developing meningitis again in the late teens

Question 11

Why are elderly patients at increased risk of infection?

Answer 11

In elderly patients, there is more chance of co-morbidities, increasing the risk of infection

Question 12

Why does gender influence infection?

Answer 12

Some infections are more common in one gender than the other

Question 13

Give an example of a infection that is more common in one gender than the other

Answer 13

UTIs are more common in women than men

Question 14

Why are UTIs more common in women?

Answer 14

Due to the anatomically different positions of the anus and the urethral opening

Question 15

How can physiological state affect infection?

Answer 15

Changes in physiological state, especially hormone levels, can put a person at more risk of infection

Question 16

Give two examples of when physiological state can change the risk of infection

Answer 16

Pregnancy

Different stages of the menstrual cycle

Question 17

What effect does pregnancy have on infection?

Answer 17

During pregnancy, there are hormone changes that put women at risk of infection

Question 18

What effect does different stages of menstrual cycle have on infection?

Answer 18

During different stages of the menstrual cycle of pH of the vagina can become raised allowed overgrowth of candida (thrush)

Question 19

How can pathological state affect infection?

Answer 19

Some pathologies can cause people to become immunocompromised
Medical treatments due to other pathologies can increase the chance on infection

Question 20

What pathologies can cause people to become immunocompromised?

Answer 20

AIDS

Genetic disorders

Question 21

Give an example of a genetic disorder that can cause immunocompromisation

Answer 21

Complement deficiencies

Question 22

What medical treatments can increase the chance of infection?

Answer 22

Chemotherapy
Immunosuppressants
Catheters
Surgery

Question 23

Why does chemotherapy and immunosuppressants increase the risk of infection?

Answer 23

Cause the patient to become immunocompromised (obvs the answers in the name lol)

Question 24

Why do catheters increase the risk of infection?

Answer 24

They breach the primary immune system and can allow the skin commensals to become pathogenic

Question 25

Give an example of an infection that can occur as a result of a catheter

Answer 25

Staphylococcus epidermidis can cause endocarditis

Question 26

How can surgery increase the risk of infection?

Answer 26

Can allow infectious agents to bypass the body's primary immune system

Question 27

How can social factors affect the risk of infection?

Answer 27

Poor social and living conditions are associated with increase risk of infection

Question 28

Give an example of a social factor that can increase the risk of infection

Answer 28

Children in nurseries often have dirty hands, so when one child has an infection, it often spreads to other children and the parents

Question 29

In what ways can time be considered when looking at infection?

Answer 29

Calendar time | Relative time

Question 30

Give an example of where calendar time can affect infection

Answer 30

Flu and norovirus infections are more common in winter

Question 31

What is meant by relative time in infection?

Answer 31

Time relative to other cases

Question 32

Give an example of an infection where relative time is important to consider

Answer 32

Chickenpox

Question 33

When is relative time regarding infection useful?

Answer 33

When trying to diagnose

Question 34

In what way can place be considered when looking at infection?

Answer 34

Current | Recent

Question 35

Why is the current place important when considering infection?

Answer 35

Environment can affect nutrition and diet | Infections can spread in hospitals if infection control is poor

Question 36

Why is it important to ask patients about recent locations?

Answer 36

Must know about recent travel as some infections are more prevalent in some countries than others, which may help identify the cause of infection

Question 37

What does the mechanism of infection vary depending on?

Answer 37

The type of infection

Question 38

What are the potential mechanisms of infection?

Answer 38

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

Question 39

What is meant by contiguous spread?

Answer 39

From one part of the body to another

Question 40

What should be sterile in the body?

Answer 40

Anything under the skin, including the blood

Question 41

Give an example of when inoculation with infection could occur

Answer 41

During surgery

Question 42

What is haematogenous spread?

Answer 42

Any spread through the bloodstream

Question 43

What happens in ingestion of an infectious agent?

Answer 43

Eating or drinking of contaminated items

Question 44

What is ingestion of pathogenic organisms often part of?

Answer 44

Fecal-oral transmission

Question 45

What happens in inhalation of pathogenic organisms?

Answer 45

Breathing in droplets or aerosols

Question 46

Where is vector transmission important?

Answer 46

Worldwide in the spread of malaria, and more recently the Zika virus

Question 47

Why is vector transmission of less concern in the UK?

Answer 47

It is not very common

Question 48

What is vertical transmission?

Answer 48

Transmission from mother to infant

Question 49

How can vertical transmission occur?

Answer 49

Can be transmitted across placenta From vagina if membranes are broken At time of delivery

Question 50

What do the symptoms of infection occur due to?

Answer 50

A complex interaction of a range of factors

Question 51

What factors interact to determine the symptoms of an infection?

Answer 51

Attachment can lead to toxin production and interaction with host defences. Interaction with host defences can lead to inflammation. Inflammation, interaction with host defences, and toxin production can lead to host damage

Question 52

What are the types of toxins produced by bacteria?

Answer 52

Exotoxins | Endotoxins

Question 53

What releases exotoxins?

Answer 53

Bacteria

Question 54

What do exotoxins do?

Answer 54

Released into environment to aid reproduction

Question 55

When are endotoxins produced?

Answer 55

When bacteria break down

Question 56

What are endotoxins?

Answer 56

A component of the cell wall of gram -ve bacteria

Question 57

What can host damage occur due to in infection?

Answer 57

Directly due to microbe actions | Indirectly via damaging inflammatory responses

Question 58

What will management of a patient vary depending on?

Answer 58

Location Severity Causative agent of an infection

Question 59

What does management of an infection consist of?

Answer 59

Diagnosis Treatment Infection prevention

Question 60

What does diagnosis of an infection consist of?

Answer 60

History Examination Investigations

Question 61

What is the purpose of diagnosis of an infection?

Answer 61

Where the infection is | What caused the infection

Question 62

What are the categories of treatment for infection?

Answer 62

Specific treatments | Supportive treatments

Question 63

What are the specific treatments of infection?

Answer 63

Antimicrobials | Surgery

Question 64

What are the categories of antimicrobials?

Answer 64

Antibiotics Antifungals Antivirals

Question 65

Why may surgery be required in the treatment of infection?

Answer 65

Remove necrotic tissue from an abscess Drainage Debridement Dead space removal

Question 66

Give an example of when drainage would be required in infection

Answer 66

Chest drain of pus in pleural space

Question 67

What happens in debridement?

Answer 67

Cut away infected tissue

Question 68

Give an example of an infection where debridement may be required

Answer 68

Necrotising fasciitis

Question 69

What is the problem with debridement surgery?

Answer 69

It can be mutilating

Question 70

Why is dead space removal sometimes required in infection?

Answer 70

Removes space for bacteria to divide into

Question 71

Why is the use of surgery in infection management decreasing?

Answer 71

Some of the things that used to be treated with surgery can now be treated with drugs

Question 72

What are the supportive treatments for infection?

Answer 72

Symptom relief | Physiological restoration

Question 73

What symptom relief can be given in infection?

Answer 73

Pain relief | Antipyretics

Question 74

Give an example of where physiological restoration is very important in infection

Answer 74

Septic shock

Question 75

Where can infection prevention take place?

Answer 75

Hospital | Community

Question 76

What are the potential outcomes of infections?

Answer 76

Cure Chronic infection, with or without a disability Death