Introduction to Infection Flashcards Preview

[ ESA 3- Infection and Immunity > Introduction to Infection > Flashcards

Flashcards in Introduction to Infection Deck (79):
1

What is an infection? 

An invasion of a host's tissue by micro-organisms 

2

What is disease caused by? 

  • Microbial multiplication 
  • Toxins
  • Host response 

 

3

What is the importance of the host response causing a lot of damage? 

When looking at managing patients, need to take into account what the host is doing 

4

How can people get infections? 

  • Directly from source
  • Through an intermediary 
  • From the environment
  • From animals
  • Themselves

 

5

Give an example of an intermediary that can cause disease

Mosquito

6

What environmental sources are there of disease? 

  • Water
  • Food
  • Air
  • Surfaces 

 

7

What is the importance of disease transmitted through water? 

Many young children killed by diarrhoea every year, mostly as a result of ingesting contaminated water 

8

What diseases are particularly caused by ingested of contaminated food? 

Gastroenteritis 

9

How can air transmit disease? 

If it is contaminated by environmental organisms 

10

Give an example of a surface that can become contaminated by pathogens 

Medical devices 

 

11

What is the importance of the contamination of medical devices? 

Potentially very important/dangerous infections, e.g. viral hepatitis, HIV

12

What is it called when a disease is transmitted by an animal? 

Zoonosis 

13

How can animals get infections? 

From the environment, or infect the environment which then infects the patient 

14

How can a person get an infection from themselves? 

Organisms that the patient has in one place can spread to another place 

15

What is meant by microbiota?

An ecological collection of microorganisms that are carried on the skin and mucosal surfaces 

16

Are microbiota harmful? 

They are normally harmless, or even beneficial, but can be harmful if they transfer to other sites 

17

Give an example of where transfer of the microbiota can cause disease? 

E. Coli from the large bowel getting into the urinary tract can use a UTI

18

What is true of many organisms considered to be pathogenic? 

Many organisms considered to be pathogenic are only so when they're in the wrong place 

19

What is meant by microbiome? 

It is a description of the entire ecosystem, including the host 

20

Give an example of a group of infections that require physical contact for transmission

Sexually transmitted infections 

21

Give an example of an infection where airborne spread is sufficient for transmission

Chickenpox

22

What are aerosols?

Small particles that can suspend in air 

23

What do aerosols allow? 

Air can remain infectious from some hours after someone infected has been in a room 

24

Give an example of an infection where a vector is required for spread

Malaria 

25

What are the modes of horizontal transport? 

  • Contact
  • Inhalation 
  • Ingestion 

 

26

What kinds of contact can transmit infection? 

  • Direct
  • Indirect
  • Vectors

 

27

What can be inhaled to spread infection? 

  • Droplets 
  • Aerosol 

 

28

What kind of transmission is common through ingestion? 

Faecal-oral transmission 

29

What are the modes of vertical transmission? 

Mother to child 

30

When can infection be spread from mother to child? 

Before or after birth 

31

Give an example of an infection that be transmitted mother to child? 

HIV

32

By what process do microorganisms cause disease? 

  1. Exposure
  2. Adherence
  3. Invasion 
  4. Multiplication
  5. Dissemination 

 

33

What types of pathogens invade? 

All viruses, some bacteria 

34

How are pathogens disseminated? 

Either by continous spread, or other ways, such as the haemotaginous route

35

What is meant by continous spread? 

Spreading locally 

36

What is meant by haemotaginous spread? 

Spread in the blood 

37

What does the mechanism of dissemination determine? 

Other aspects of the disease 

38

What are the determinants of disease? 

  • Pathogen
  • Patient 

 

39

What pathogen factors determine disease? 

  • Virulence factors 
  • Inoculum size 
  • Antimicrobial resistance 

 

40

What does virulence factors vary between? 

  • Different organisms 
  • Individual organisms of the same species

 

41

What is the effect of inoculum size on disease? 

More likely to get infection if infectious load is large

42

What patient factors determine disease? 

  • Site of infection 
  • Co-morbidities 

 

43

What co-morbidities affect disease outcomes? 

  • Neonates
  • Recent surgery
  • Diabetes
  • Malignancy 

 

44

What questions must be answered when a patient presents with an infection? 

  • Is there an infection? 
  • Where is the infection?
  • What is the cause of the infection?
  • What is the best treatment? 

 

45

Why may no treatment be given for an infection? 

  • There may be no treatment available 
  • The infection might be self limiting

 

46

What must be done to determine what infection a patient has? 

  • History 
  • Examination
  • Investigations

 

47

What should be determined in the history of a patient with an infection? 

  • Symptoms
  • Potential exposures

 

48

What information should be gathered about the symptoms of an infection? 

  • What is the patient complaning of? 
  • Are they focal or systemic? 
    • Can be both 
  • Severity 
  • Duration

 

49

Give 3 examples of systemic symptoms of infection

  • Weight loss
  • Fever
  • General malaise 

 

50

What questions must be asked to determine potential exposures to an infection? 

  • Where have they been? 
  • What have they been doing? 
  • Who have they been doing it with? 
  • Were there any animals involved?

 

51

What should be looked for on examination of someone with an infection? 

Organ dysfunctions 

52

What are the categories of investigations in a patient with an infection? 

  • Specific
  • Supportive

 

53

What are the specific investigations into someone with a infection? 

Microbiological 

54

What is meant by supportive investigations into infection? 

Investigations which help indicate the possibility of infection, severity, and prognosis, and how the patient is responding to treatment 

55

What are the supportive investigations into infection? 

  • Full blood count 
  • C-reactive protein (CRP)
  • Blood chemistry 
  • Imaging
  • Histopathology 

 

56

What is being looked for in a FBC when investigating infection? 

  • Neutrophils 
  • Lymphocytes 

 

57

What is CRP indicative of? 

Infection 

58

What is done when conducting a blood chemistry investigation in infection? 

Liver and kidney function 

59

Give an example of where a liver function test can help determine the cause of infection? 

In viral hepatitis, transaminases normally go up 

60

What can kidney function tests give in infection? 

Dose suggestions for some drugs 

61

What imaging is done when investigating infections? 

  • X-ray 
  • Ultrasound
  • MRI

 

62

How is the precise cause of infection determined? 

Bacteriology or virology 

63

What specimen types are used in bacteriology? 

  • Swabs
  • Fluids
  • Tissues

 

64

What can be swabbed to obtain a specimen in bacteriology? 

  • Throat 
  • Rectum
  • Wound

 

65

What fluids can be used as the specimen in bacteriology? 

  • Urine
  • Blood

 

 

66

What techniques of bacteriology are used? 

  • M, C, & S 
  • Antigen detection 
  • Nucleic acid detection 

 

67

What is M, C, & S? 

  • Microscopy 
  • Culture
  • Antibiotic susceptibility 

 

68

What is looked at in the microscopy phase of M, C, & S? 

  • Bacterial cells 
  • Patient cells 

 

69

What can be used to look at bacterial cells? 

Gram stain 

70

What patient cells are looked at in M, C, & S? 

CSF

71

How is nucleic acid detected in bacteriology? 

PCR 

72

Does the bacteria have to be alive to conduct PCR? 

No 

73

What techiques of virology are used? 

  • Antigen detection 
  • Antibody detection 
  • Detecting viral nucleic acid 

 

74

What happens in antigen detection in virology? 

Use antibody to capture antigen, and then demonstrate presence using flourescent marker 

75

What does antigen detection in virology determine? 

The presence of a virus 

76

What happens in antibody detection in virology? 

Use antigen as capture mechanism 

77

What does antibody detection in virology determine? 

The patient's response 

78

What does the detection of viral nucleic acid determine? 

DNA or RNA

79

Who is involved in managing infections? 

All clinicians encounter patients with infections, but specialities whos primary interest in infection are; 

  • Infectious diseases
  • Medical microbiology and virology
  • Genitourinary medicine
  • Health protection