Session 5 Flashcards
(53 cards)
1
Q
What are healthcare infections?
A
Infections that arise as a consequence of providing healthcare (eg. while in hospital)
- Not present at time of admission
2
Q
Who gets healthcare infections?
A
- Inpatients and outpatients
- Visitors
- Healthcare workers
3
Q
Why are healthcare infections important?
A
- Frequent: 8% of inpatients
- Impact on health: very detrimental
- Healthcare organisation: more bed-days if you catch an infection, for example after surgery
- They’re preventable
4
Q
What are the most common hospital acquired infections?*
A
- Gastrointestinal (21%)
- Urinary tract infections (20%)
- Hospital-acquired pneumonia
- Surgical wound infections
- Others (eg. post-op meningitis, post surgical)
5
Q
Where in the infection model can preventative methods be introduced?*
A
- Preventing pathogen + patient getting together AND becoming an infection
- Prevent pathogen getting to patient in the first place
- Prevent infection spreading between patients
6
Q
What are some key viruses in healthcare infection?
A
- Hep B
- HIV
- Norovirus (doctors and nurses very vulnerable)
- Influenza (very risky if immunocompromised)
- Chickenpox
7
Q
What are some key bacteria in healthcare infection?
A
- Staph aureus (inc. MRSA)
- C. diff
- E. coli
- Mycobacterum tuberculosis
8
Q
What are some key fungi and parasites in healthcare infection?
A
Fungi:
- Candida albicans (cancer/transplant patients)
- Aspergillus
Parasite:
- Malaria
9
Q
What are features of patients who are most susceptible to infections?
A
All linked to immunocompromise.
- Age (children/elderly)
- Obesity/malnourishment
- Diabetes
- Cancer
- Immunosuppression
- Smoker
- Surgery
- Emergency admission
10
Q
What are the 4 Ps of infection control?*
A
- Patient
- Pathogen
- Practice
- Place
11
Q
What are some general patient interventions (to prevent patient’s own microflora causing infections in wrong places)?
A
- Optimise patient condition (smoking, nutrition)
- Antimicrobial prophylaxis (one dose before procedure so they’re present at site of surgery)
- Skin preparation (before surgery)
- Hand hygiene
- Diabetes and malnutrition are a high risk of surgical site infections
12
Q
Why is it important to know which patients are high-risk?
A
Can hopefully prevent spreading to healthcare professionals.
13
Q
What are some specific patient interventions?
A
- MRSA screens
- Disinfectant body wash
- Muciprocin nasal ointment (prevents S. aureus spread)
14
Q
What are some interventions that can halt patient-patient transmission?
A
- Isolation of infected patients (eg. own room rather than on ward)
- Protection of susceptible patients
15
Q
What are some interventions to prevent infection?
A
- Healthcare workers should be vaccinated if vaccine available
- Good clinical techniques (sterile, non-touch)
- Good hand hygiene
- Protective equipment (PPE) - face masks, etc.
- Antimicrobial prescribing (key in resistant infections)
16
Q
What are some environmental interventions that can be implemented to prevent spread from the environment to patient?
A
- Clean toilets and hand washing basins
- Disinfectants
- Steam cleaning
- H2O2 vapour (decontaminated but ward must be empty)
- Medical devices (should be single use or sterilised)
- Good food and water hygiene
- Good food facilities
- Positive/negative pressure rooms
- Protection for immunosuppressed patients
17
Q
What are the features of Patient in 4Ps?
A
- General/specific risk factors
- Interactions with other people
18
Q
What are the features of Practice in 4Ps?
A
- What healthcare workers do (eg. venflons in)
- Organisation
- Leadership from government
19
Q
What are the features of Pathogen in 4Ps?
A
- Virulence factors (why so infectious)
- Ecological interaction with antibiotics/disinfectants and other bacteria
20
Q
What are the features of Place in the 4Ps?
A
- Environment (eg. isolation rooms, bays)
- Increased space between beds in patient wards reduces spread
- Must be easy to clean and decontaminate
21
Q
What are the 5 Is?
A
- Identify - what the infection is, where it was acquired and what the symptoms are, who is at high risk
ABCDEF
(abroad, blood borne, colonised, diarrhoea, expectorating, funny rash) - Isolate - prevent spread
- Investigate
- Inform
- Initiate
22
Q
What are positive pressure rooms?
A
- Air at high pressure
- Patient’s room is at lower pressure than lobby
- Air drawn out of patient’s room and into extractor instead of into room
- Prevents air movement from patient’s room and vice versa
23
Q
What are negative pressure rooms?
A
- Allow air into insulation room
- Prevents air getting out
24
Q
What are the common sources of infection?*
A
- Environmental (Legionella pneumophilia)
- Food/water (food poisoning)
- Animals (rabies)
All then spread to other people and onwards transmission is also possible for some
25
What is person-to-person direct transmission?*
When one person can catch the pathogen from another. No other sources are involved.
(eg. via droplets, sex, etc)
- Influenza (can also be animal-human, eg. swine flu)
- Norovirus
- Neisseria gonnorhoea
26
What is person-to-person indirect transmission?
Transmission from person to person but via vector
| eg. malaria - mosquito as vector
27
What is the definition of an endemic disease?
Disease occurring at an usual background rate
28
What is the definition of an outbreak?
Two more cases linked in time and place (evidence of transmission)
29
What is the definition of an epidemic?
A rate of infection that is greater than the usual background rate
- Some people are immune to it
30
What is the definition of a pandemic?
- Very high rate of infection
- Spread across many regions/countries/continents
- Novel agent, no immunity
31
What is the basic reproduction number? (Ro)
The average number of cases that one case can generate over the course of its infectious period in an otherwise uninfected, non-immune population
32
What does it mean if Ro >1 ?
There is an increase in cases.
- Spread rapidly through a population
- If patients recover, then there will be no more people to infect due to immunity or death
33
What does it mean if Ro =1?
The number of cases is stable.
34
What does it mean if Ro <1?
There is a decrease in cases.
35
What are the reasons for outbreaks, epidemics and pandemics?*
- New pathogens
- New hosts
- New practice
36
What is meant by new pathogens?
- Completely novel (eg. COVID-19)
- Can have different antigens on an old virus and therefore we are no longer immune
- Antibacterial resistance
37
What is meant by new hosts?
- People who are non-immune (eg. babies after antibody transfer from mother wears off) - immune-naive
- Moving people to different places
38
What is meant by new practices?
- Novel practices (eg. tattoos and spreading bloodborne viruses)
- Unprotected sex, gay saunas (HIV relevance)
-
39
What determines transmissibility?
Infectious dose: number of microorganisms requires to cause infection
(some are extremely infectious - eg. one particle needed for norovirus)
40
What factors does the infectious dose vary by?
- Micro-organism
- Presentation of micro-organism
- Immunity of potential host (fit and healthy or vulnerable)
41
What are epidemic curves?*
Graphs that show number of people infected at each time.
(susceptible -> infected -> recovered) - SIR model
eg. novel agent introduced
42
What is the nature of small outbreaks?*
- Less predictable
- Stochastic nature = random elements, bad luck/good luck
- Can get apparent response just by chance
43
What are the interventions? Look at the diagram to see where they can be introduced.
**
- Pathogen: reduction/eradication
- Patient: improved health and immunity
- Practice: behavioural change/protective equipment
- Place: environmental engineering
44
How can pathogens/vectors be reduced or eradicated?
Pathogen:
- Antibacterials/disinfectants
- Decontamination (e.g. safe water supplies)
- Sterilisation
Vector:
- Eliminate breeding sites
45
How can interventions to patients be introduced?
- Nutrition and medical treatment to improve health
- Passive Immunity: maternal antibody, IV immunoglobulin
- Active Immunity: vaccinations
46
What is herd immunity?*
Where a high proportions of the population are immune, particularly via vaccinations so that their own antibodies are produced.
- Prevents spread of disease to the people who were vaccinated
47
What are some interventions that can be put into practice?
- Avoidance of pathogen
| - Behavioural
48
How do you avoid a pathogen?
- Avoid going to where pathogen is found
| - Use protective clothing and equipment (eg. long sleeves and trousers, PPI in hospitals)
49
What are examples of behavioural interventions to prevent transmission?
- Safe sex
- Safe sharps disposal
- Food and drink preparation
50
What are examples of environmental engineering?
- Safe water (eg. cholera prevention)
- Safe air
- Good quality housing
- Good healthcare facilities
51
What are the good consequences of control?
- Decreased incidence of disease (eg. polio)
| - Eradication (eg. smallpox)
52
What are bad consequences of control?
- Decreased exposure to pathogen means that there are decreased immune stimuli, so people have less antibodies and are more susceptible which makes an outbreak more likely
- Later average age of exposure results in more severity (eg. chickenpox, polio)
53
Why is surveillance important?
To know what is happening now and what might happen later.
