An Infection Model Flashcards Preview

[ ESA 3- Infection and Immunity > An Infection Model > Flashcards

Flashcards in An Infection Model Deck (76):
1

What does an infection model allow for?

A simplistic look at the progress of most infections

2

What does an infection model show?

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

3

What is the infection model?

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

4

What are the classes of pathogens causing disease?

Virus
Bacterium
Fungus
Parasite

5

What are the classes of fungi?

Yeast
Moulds

6

What are the classes of parasites?

Protozoa
Helminth

7

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

Specific characteristics concerning the patient and their lifestyle

8

What person factors can influence the outcome of infection?

Age
Gender
Physiological state
Pathological state
Social factors

9

Why does age influence the type or severity of infection?

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

10

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

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

11

Why are elderly patients at increased risk of infection?

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

12

Why does gender influence infection?

Some infections are more common in one gender than the other

13

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

UTIs are more common in women than men

14

Why are UTIs more common in women?

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

15

How can physiological state affect infection?

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

16

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

Pregnancy
Different stages of the menstrual cycle

17

What effect does pregnancy have on infection?

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

18

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

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

19

How can pathological state affect infection?

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

20

What pathologies can cause people to become immunocompromised?

AIDS
Genetic disorders

21

Give an example of a genetic disorder that can cause immunocompromisation

Complement deficiencies

22

What medical treatments can increase the chance of infection?

Chemotherapy
Immunosuppressants
Catheters
Surgery

23

Why does chemotherapy and immunosuppressants increase the risk of infection?

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

24

Why do catheters increase the risk of infection?

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

25

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

Staphylococcus epidermidis can cause endocarditis

26

How can surgery increase the risk of infection?

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

27

How can social factors affect the risk of infection?

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

28

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

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

29

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

Calendar time
Relative time

30

Give an example of where calendar time can affect infection

Flu and norovirus infections are more common in winter

31

What is meant by relative time in infection?

Time relative to other cases

32

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

Chickenpox

33

When is relative time regarding infection useful?

When trying to diagnose

34

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

Current
Recent

35

Why is the current place important when considering infection?

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

36

Why is it important to ask patients about recent locations?

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

37

What does the mechanism of infection vary depending on?

The type of infection

38

What are the potential mechanisms of infection?

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

39

What is meant by contiguous spread?

From one part of the body to another

40

What should be sterile in the body?

Anything under the skin, including the blood

41

Give an example of when inoculation with infection could occur

During surgery

42

What is haematogenous spread?

Any spread through the bloodstream

43

What happens in ingestion of an infectious agent?

Eating or drinking of contaminated items

44

What is ingestion of pathogenic organisms often part of?

Fecal-oral transmission

45

What happens in inhalation of pathogenic organisms?

Breathing in droplets or aerosols

46

Where is vector transmission important?

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

47

Why is vector transmission of less concern in the UK?

It is not very common

48

What is vertical transmission?

Transmission from mother to infant

49

How can vertical transmission occur?

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

50

What do the symptoms of infection occur due to?

A complex interaction of a range of factors

51

What factors interact to determine the symptoms of an infection?

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

52

What are the types of toxins produced by bacteria?

Exotoxins
Endotoxins

53

What releases exotoxins?

Bacteria

54

What do exotoxins do?

Released into environment to aid reproduction

55

When are endotoxins produced?

When bacteria break down

56

What are endotoxins?

A component of the cell wall of gram -ve bacteria

57

What can host damage occur due to in infection?

Directly due to microbe actions
Indirectly via damaging inflammatory responses

58

What will management of a patient vary depending on?

Location
Severity
Causative agent of an infection

59

What does management of an infection consist of?

Diagnosis
Treatment
Infection prevention

60

What does diagnosis of an infection consist of?

History
Examination
Investigations

61

What is the purpose of diagnosis of an infection?

Where the infection is
What caused the infection

62

What are the categories of treatment for infection?

Specific treatments
Supportive treatments

63

What are the specific treatments of infection?

Antimicrobials
Surgery

64

What are the categories of antimicrobials?

Antibiotics
Antifungals
Antivirals

65

Why may surgery be required in the treatment of infection?

Remove necrotic tissue from an abscess
Drainage
Debridement
Dead space removal

66

Give an example of when drainage would be required in infection

Chest drain of pus in pleural space

67

What happens in debridement?

Cut away infected tissue

68

Give an example of an infection where debridement may be required

Necrotising fasciitis

69

What is the problem with debridement surgery?

It can be mutilating

70

Why is dead space removal sometimes required in infection?

Removes space for bacteria to divide into

71

Why is the use of surgery in infection management decreasing?

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

72

What are the supportive treatments for infection?

Symptom relief
Physiological restoration

73

What symptom relief can be given in infection?

Pain relief
Antipyretics

74

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

Septic shock

75

Where can infection prevention take place?

Hospital
Community

76

What are the potential outcomes of infections?

Cure
Chronic infection, with or without a disability
Death