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[ ESA 3- Infection and Immunity > Infection Prevention > Flashcards

Flashcards in Infection Prevention Deck (145):
1

How do many infections remain tranmissible?

Common non-human source
Person-to-person direct
Person-to-person indirect

2

What is meant by a common non-human source?

A common source that a potential host comes into contact with, and acquires the infection

3

What can happen once a potential host has acquired the infection?

It can then be passed from person to person

4

What are the potential common non-human sources?

Environmental source
Food/drink
Animals

5

Give an example of a disease which has an environmental source?

Legionnaires disease

6

What is legionnaires disease caused by?

Legionella pneumophila

7

Where can Legionella pneumophilia come from?

A common water source

8

How can a common water source spread Legionella pneumophilia?

The water source usually creates water droplets, and the bacteria is then spread via the droplet to a person

9

Give two examples of where a water source can create water droplets

Shower
Fountain

10

Is Legionnaires considered transmissible between people?

No

11

Give an example of a pathogen that can be spread in food or drink

E. Coli

12

Where is E. coli o157 found?

In the GI tract of cows

13

What can E. coli o157 cause?

Gastrointestinal disease

14

When can E. coli o157 cause gastrointestinal disease?

If it gets into meat/milk

15

How can E. coli o157 from meat/milk be transmitted between people?

Via faecal oral route

16

Give an example of a disease that can spread through animals

Rabies

17

How does an animal act as a 'common source' for rabies?

It bites more than one person

18

What is meant by person-to-person direct transmission?

Spread from one person to another without intermediate, and this newly infected person can go on to infect someone else

19

Give three examples of disease spread person-to-person direct

Norovirus
Influenza
Neisseria gonorrhoea

20

How high does exposure to norovirus need to be to cause disease?

A very minimal exposure of 1 infectious particle is enough to cause infection in 50% of the population

21

What is meant by 1 infectious particle?

A clump of viruses bound by faeces, for example

22

Where does norovirus spread often occur?

In an enclosed environment

23

How is norovirus transmitted?

Faecal/oral route

24

How is influenza transmitted from person to person

By droplet transmission

25

Can influenza be spread from to humans from animals?

Yes

26

How is Neisseria gonorrhoea spread?

Direct contact with another person

27

What happens in person-to-person indirect transmission?

Transmission occurs via a vector and cannot usually be transmitted onwards without one

28

Give three examples of diseases spread person-to-person indirect

Malaria
Guinea worm
Schistosomiasis

29

How is malaria transmitted?

Via a mosquito that bites an infected individual, which then bites another individual

30

What happens when a mosquito bites an infected individual?

It picks up the plasmodium into their blood

31

How does the mosquito infect another person when it bites them?

It injects the infection into them via saliva

32

What can happen once a person has been infected with malaria?

The person can be bitten by another mosquito that can pass the disease on again

33

How is guinea worm transmitted?

A person with the worm washes their feet in water, allowing larvae to be hatched into it.
An aphid then eats the larvae and sits in the water
Ingestion of the aphid allows the larvae to evade digestion and survive in the GI tract, where it burrows to the feet to continue the cycle

34

How can schistosomiasis be transmitted?

Through snails

35

What is meant by endemic disease?

The usual background rate of disease within a community with no extra factors to consider

36

What does the rate depend on in endemic disease?

The disease in question

37

What is an outbreak?

Two or more cases linked in time and place

38

What must be true for cases to be an outbreak?

The causative organisms must be of the same type

39

What is meant by an epidemic?

When a rate of infection is greater than the usual background rate

40

What is meant by pandemic?

A very high rate of infection spreading across many regions, countries, or contients

41

Give an example of a pandemic

Swine flu in 2009

42

What happened in the 2009 swine flu pandemic?

Originated in Mexico and spread throughout the world

43

What is the problem with pandemics?

They can cause large disruption to healthcare

44

What is how quickly an infection spreads affected by?

Its basic reproduction number (R0)

45

What is R0?

The average number of cases one case generates over the course of its infectious period, in an otherwise infected, non-immune population

46

What happens if R0 > 1?

The number of cases will increase

47

What happens if R0 = 1?

The number of cases will remain the same

48

What happens if R0 < 1?

Number of cases will decrease

49

When will an outbreak stop?

If everyone dies
Disease is overcome and immunity is developed

50

What diseases send to have a high R0?

Diseases spread by airborne route

51

Give two examples of diseases spread by airborne route with a high R0?

Measles
Pertussis

52

What is the R0 of measles?

12-18

53

What is the R0 of pertussis?

12-17

54

Give an example of a disease spread by the airborne route with a low R0

Influenza

55

What is the R0 of influenza?

Can be as low as 2-3

56

What may the low R0 of influenza be a reflection of?

The development of personal immunity

57

What kind of diseases tend to have a low R0?

Diseases that are spread through sexual contact

58

Give an example of a disease spread by sexual contact that has a low R0

HIV

59

What is the R0 of HIV?

2-5

60

Why do diseases that spread by sexual contact have a low R0?

It is a contact that is less likely to occur

61

What do reasons for outbreaks, epidemics and pandemics relate to?

Pathogen
Patient
Practice

62

What pathogen factors can lead to outbreaks, epidemics, and pandemics?

The introduction of new pathogens or pathogenic features

63

What pathogenic features can be introduced that lead to outbreaks, epidemics, and pandemics?

New antigens on pathogens surface
New virulence factors
Antibacterial resistance

64

Give an example of a pathogen that often mutates its surface antigens

Influenza

65

Give an example of a pathogen that may develop new virulence factors to cause outbreaks, epidemics and pandemics

C. Diff

66

Give an example of a pathogen that has antibiotic resistance

MRSA

67

What patient factors can lead to outbreaks, epidemics, and pandemics?

Introduction of new hosts

68

In what form are non-immunes introduced into the communities all the time?

Babies that have not yet developed immunity

69

What is the result of non-immunes being introduced into the community?

There is more chance of the person becoming infected and spreading it to others

70

How can healthcare cause outbreaks, epidemics, and pandemics?

It can bring people into close contact with people that are infected, allowing a route for infection to spread throughout the population

71

What changes in human practice can cause outbreaks, epidemics, and pandemics?

Social practices
Healthcare practices

72

Give an example of a social practice that can lead to outbreaks, epidemics, and pandemics

Increases in the number of body piercings have caused outbreaks due to unsanitary procedures

73

Give three examples of healthcare practices that can lea to outbreaks, epidemics, and pandemics

Surgery
Central line usage
Immunosuppression

74

What is transmissibility affected by?

The infectious dose

75

What is the infectious dose?

The number of microorganisms required to cause infection

76

What can infectious dose vary depending on?

The type of microorganism
Presentation of microorganism
Immunity of potential host

77

What can the immunity of the potential host be affected by?

A large number of factors, including genetic disorders, infections like HIV, cancer, and different treatments

78

What is the infectious dose for cholera?

10^4 - 10^6 organisms

79

What is the infectious dose of E. Coli o157?

<10 organisms

80

What trend to transmissions of infections often follow?

An epidemic curve

81

What does the epidemic curve of infection transmission show?

The progression of the majority of the population from susceptibility, to infection, and then to recovery

82

What nature of epidemic curve does small scale outbreaks?

Stochastic nature

83

Why do small scale infections show a stochastic epidemic curve

Due to the random nature of transmission of infection in small populations

84

How can infection be prevented?

Via intervention at a number of stages of the infection model

85

What interventions can be made at stages of the infection model to prevent infection?

Prevention of pathogens initial existence
Prevention of patient coming into contact with an existing pathogen
Prevention of development of patient/pathogen contact into infection
Prevention of further infection to other individuals

86

What can infection prevention be protein down into?

The 4 P's

87

What are the 4 P's?

Pathogen (and vectors)
Patient
Practice
Place

88

How can infection be prevented when considering the pathogen?

Reduction/eradication of a pathogen Reduction/eradication of a vector

89

How can a pathogen be reduced or eradicated?

Effective use of antibacterial and disinfectants

90

What does the effective use of antibacterials and disinfectants allow for?

Decontamination and sterilisation of surfaces, equipment, and the environment

91

How can a vector be reduced or eradicated?

Eliminating breeding sites
Killing or controlling existing vectors

92

What vector can be reduced/eradicated by eliminating breeding sites?

Mosquitos

93

What vector can be reduced/eradicated by killing or controlling existing vectors?

Rapid animals

94

How can infection be prevented when considering the patient?

Improve health
Immunity

95

How can health be improved in the patient to prevent infection?

Nutrition and medical treatment

96

What kinds of immunity can be conveyed to the patient to prevent infection?

Passive
Active

97

How can passive immunity be conferred to patients?

Maternal immunity
Intravenous immunoglobulin

98

How can active immunity be conveyed to the patient to prevent infection?

Vaccination

99

How can herd immunity be used?

By vaccinating a proportion of the population to reduce the amount of potential people that can cause secondary transmission and thus protecting unvaccinated people by decreasing their likelihood of coming into contact with someone with an infection

100

What does the proportion of the population that needs to be vaccinated for herd immunity to work vary with?

The R0 of the infection

101

How can infection be prevented when considering practice?

Avoidance of pathogen or its vector

102

In what ways can the pathogen or vector be avoided?

Geographic
Protective clothing or equipment
Behavioural

103

What protective clothing or equipment can be used to prevent infection?

Long sleeves/trousers against mosquito bites
PPE in hospitals

104

What PPE is used in hospitals?

Gowns
Masks
Gloves

105

What behavioural practices can be used to prevent infection?

Safe sex
Safe disposal of sharps
Food and drink preperation

106

How can infection be prevented when looking at the place?

Environmental engineering

107

How can environmental engineering prevent infection?

Safe water
Safe air
Good quality housing
Well designed healthcare facilities

108

How can surveillance be used to prevent infection?

Monitor what is happening now
What could happen in the future

109

What are the consequences of good infection control?

Decreased incidence of disease/organism

110

What diseases have decreased incidence due to good infection prevention?

Smallpox
Polio
Dracunculiasis

111

What is the consequence of bad infection control?

Decreased exposure to pathogen
Later average age of exposure

112

What does decreased exposure to pathogen lead to?

Decreased immune stimulus

113

What is the result of a decreased immune stimulus?

Decreased antibody

114

What is the result of decreased immune antibodies?

Increased susceptible people

115

What is the result of increased susceptible people

Outbreak

116

What is the result of a later age of exposure to infection?

Increased severity

117

What diseases have an increased severity at a later age of exposure?

Polio
Hepatitis A
Chickenpox
Congenital rubella
Syndrome

118

What does all exposure of bacteria to antimicrobials lead to?

A level of antimicrobial resistance

119

Is antimicrobial resistance reversible?

Effectively irreversible

120

What is the problem with new antimicrobial development?

It is stalled- no new antibiotic classes since 1987

121

What are the consequences of antimicrobial resistance?

Treatment failure
Prophylaxis failure
Economic cost

122

How much does antibiotic resistance cost in the EU?

Approx €1.5billion a year

123

How many deaths per year are there in the EU from antimicrobial resistance?

25,000

124

How many deaths per year due to antimicrobial resistance are there per year in Thailand?

>38,000

125

What does the acronym MDR mean?

Multi-drug resistant

126

What is meant by multi-drug resistance?

Non-susceptibility to one agent in three or more antimicrobial categories

127

What does the acronym XDR mean?

Extensively drug resistant

128

What is meant by extensively drug resistant?

Non-susceptibility to at least one agent but two or fewer antimicrobial categories

129

What does PDR mean?

Non-susceptibility to all agents in all antimicrobial categories

130

What does antibacterial use lead to?

Resistance

131

How can the fact that antibacterial use leads to resistance be backed up?

Lab evidence
Ecological studies
Individual level data

132

What is the purpose of lab evidence when determining the link between antibacterial use and resistance?

Provides biological plausibility

133

What is the purpose of ecological studies when determining the link between antibacterial use and resistance?

Relates levels of antibacterial use in a population with level of resistance

134

What is the purpose of individual level data when determining the link between antibiotic use and resistance?

Relates prior antibacterial use in an individual with the subsequent presence of bacterial resistance

135

What does an antimicrobial stewardship programme consist of?

Multidisciplinary team and relationships to other quality/safety teams
Surveillance

136

Who does the multidisciplinary team involved with antimicrobial stewardship consist of?

Medical microbiologists/infectious diseases physicians
Antimicrobial pharmacist
Infection control nurse
Hospital epidemiologist
Information system specialist

137

What does the multidisciplinary team involved in antimicrobial stewardship link in with?

Infection prevention and environmental decomination

138

What happens in surveillance in antimicrobial stewardship?

Process measures
Outcome measures

139

What process measures are taken in antimicrobial stewardship?

Antibacterial use
Over time in same institution
Benchmarking against other institutions

140

What measures are taken of antibacterial use in antimicrobial stewardship programmes?

Quantity
Antibacterial classes
Appropriateness

141

Give an example of how quantity of antibacterial use can be measured in antimicrobial stewardship

Defined daily doses / 1000 bed days

142

What is meant by appropriateness of antibacterial use in antimicrobial stewardship?

Adherence to guidelines

143

What outcome measures are taken in antimicrobial stewardship?

Patient outcomes
Emergence of resistance
C. Difficile infection rate

144

What does antimicrobial stewardship aim to do?

Ensure appropriate use of antimicrobials
Create optimal clinical outcomes
Minimise toxicity and other adverse events
Reduce costs of health care from infections
Limit the selection for antimicrobial resistant strains

145

What are the requirements for successful antimicrobial stewardship?

Long term confirmed and appropriate resources
Hospital leadership support and delegated authority to challenge/change inappropriate antimicrobial therapy
Integration into organisational patient safety and quality of care structure and processes