Infection Prevention Flashcards
1
Q
How do many infections remain tranmissible?
A
Common non-human source
Person-to-person direct
Person-to-person indirect
2
Q
What is meant by a common non-human source?
A
A common source that a potential host comes into contact with, and acquires the infection
3
Q
What can happen once a potential host has acquired the infection?
A
It can then be passed from person to person
4
Q
What are the potential common non-human sources?
A
Environmental source
Food/drink
Animals
5
Q
Give an example of a disease which has an environmental source?
A
Legionnaires disease
6
Q
What is legionnaires disease caused by?
A
Legionella pneumophila
7
Q
Where can Legionella pneumophilia come from?
A
A common water source
8
Q
How can a common water source spread Legionella pneumophilia?
A
The water source usually creates water droplets, and the bacteria is then spread via the droplet to a person
9
Q
Give two examples of where a water source can create water droplets
A
Shower
Fountain
10
Q
Is Legionnaires considered transmissible between people?
A
No
11
Q
Give an example of a pathogen that can be spread in food or drink
A
E. Coli
12
Q
Where is E. coli o157 found?
A
In the GI tract of cows
13
Q
What can E. coli o157 cause?
A
Gastrointestinal disease
14
Q
When can E. coli o157 cause gastrointestinal disease?
A
If it gets into meat/milk
15
Q
How can E. coli o157 from meat/milk be transmitted between people?
A
Via faecal oral route
16
Q
Give an example of a disease that can spread through animals
A
Rabies
17
Q
How does an animal act as a ‘common source’ for rabies?
A
It bites more than one person
18
Q
What is meant by person-to-person direct transmission?
A
Spread from one person to another without intermediate, and this newly infected person can go on to infect someone else
19
Q
Give three examples of disease spread person-to-person direct
A
Norovirus
Influenza
Neisseria gonorrhoea
20
Q
How high does exposure to norovirus need to be to cause disease?
A
A very minimal exposure of 1 infectious particle is enough to cause infection in 50% of the population
21
Q
What is meant by 1 infectious particle?
A
A clump of viruses bound by faeces, for example
22
Q
Where does norovirus spread often occur?
A
In an enclosed environment
23
Q
How is norovirus transmitted?
A
Faecal/oral route
24
Q
How is influenza transmitted from person to person
A
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
