Healthcare Acquired Infections Flashcards

1
Q

What is a healthcare acquired infection?

A
  • Infections that were not present or in the pre-symptomatic phase at the time of admission to hospital
  • Which arise > 48 hrs after admission or within 48 hrs of discharge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the possible outcomes of HAI?

A
  • Extended length of stay, pain, discomfort, permanent disability, death
  • Increased Cost: 33% decrease in HAI in Scotland would lead to savings of £55 million (2007 National Prevalence Study)
  • Litigation
  • Loss of public confidence and decreased staff morale
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the most common sites of HAI?

A
  • UTI (related to catheterisation)
  • Surgical site infection
  • RTI (intubation)
  • Bloodstream infections (central venous catheters)
  • GI infection
  • Skin and soft tissue infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the relationship between humans and bacteria?

A
  • Approx. 10^14 bacteria in adult human
  • Approx 10 bacterial cells to every human cell
  • Human beings carry >1kg of bacteria in their gut alone
  • 500 different species of bacteria have been isolated from human stool
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are patients in hospital more vulnerable to?

A

Microbial colonisation and infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the most common form of staph aureus to be colonised with?

A

Meticillin sensitive staphylococcus aureus (MSSA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can a colonising staph aureaus cause infection?

A
  • Break in skin e.g. surgical site infection
  • Vascular device e.g. PVC, CVC
  • Catheter associated urinary tract infection (CAUTI)
  • Ventilator associated pneumonia (VAP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What process leads to most HAI?

A

A disturbance in the bacterial-host equilibrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What microbial factors can tip the bacterial-host balance towards infection?

A

Increased

  • Resistance
  • Virulence
  • Transmissability
  • Increased survival ability
  • Ability to evade host defences
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What host factors can tip the bacterial-host balance towards infection?

A
  • Devices: PVC, CVC, Urinary catheter, Ventilation
  • Antibiotics
  • Break in skin surface
  • Foreign body
  • Immunosuppression
  • ?Gastric acid suppression
  • Age extremes
  • Overcrowding
  • Increased opportunity for transmission e.g. Interventions, Hands!!!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is required for chain of infection?

A
  • Source of microbe (endogenous or exogenous)
  • Transmission
  • Host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What means of transmission are there for infection?

A

Direct contact
-e.g. Staphylococcus aureus, coliforms

Respiratory/Droplet
-e.g. Neisseria meningitidis, Mycobacteria tuberculosis

Faecal-Oral
-e.g. Clostridium difficile, Salmonella sp.

Penetrating Injury
-e.g. Group A streptococcus, Bloodborne viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How can the chain of infection be broken?

A
  • Risk awareness
  • Standard Infection Prevention and Control Precautions (SICPs)
  • Hand Hygiene
  • Appropriate PPE
  • Vaccination
  • Post Exposure Prophylaxis
  • Environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cleaning

A

Physical removal of organic material and decrease in microbial load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Disinfection

A

Large reduction in microbe numbers-spores may remain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sterilisation

A

Removal/destruction of ALL microbes and spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How should spread of infection be prevented with low risk objects such as stethoscopes, cots and mattresses which have been in contact with intact skin?

A

Cleaning compatible with manufacturer’s instructions

18
Q

How should spread of infection be prevented with medium risk objects such as bedpans, vaginal specula and endoscopes which have been in contact with mucous membranes?

A

Disinfection or sterilisation as appropriate

19
Q

How should spread of infection be prevented with high risk objects such as surgical instruments?

A

Sterilisation

20
Q

How should cleaning of equipment be carried out?

A
  • Manufacturer’s instructions
  • Detergent and water
  • DRYING IS AN IMPORTANT PART OF THE PROCESS!
  • Cleaning essential PRIOR to disinfection and Sterilisation if these are required
21
Q

What methods of disinfection are there?

A
  • Heat
  • Chemical-Steam under pressure (autoclave)
  • Gas (ethylene dioxide)
  • Ionising radiation
22
Q

How can heat be used as a method of disinfection?

A
  • Pasteurisation (e.g. bedpans, linen, dishwashers)

- Boiling (vaginal specula, ear syringes)

23
Q

How can chemical be used to disinfect items?

A
  • Chemicals vary in their organism activity range
  • Needs to be equipment compatible
  • Examples: Alcohol, chlorhexidine, hypochlorites, hydrogen peroxide
24
Q

How is local surveillance carried out for infection control?

A
  • Lab based

- Ward/clinical area based

25
Q

What types of surveillance are there for infection control?

A
  • Local surveillance

- National surveillance

26
Q

Give examples of national surveillance which has taken place in Scotland for infection control.

A
  • MRSA bacteremia
  • MSSA bacteremia
  • Clostridium difficile
  • Surgical Site Infections
  • E coli bacteremia ?
27
Q

Infection outbreak

A

An outbreak of an infection is defined as 2 or more cases of a infection linked in time and place.

28
Q

What is the purpose of IPCT?

A

Prevent individual infections and surveillance

29
Q

What is the purpose of surveillance?

A

Detect and identify a possible outbreak at the earliest opportunity

30
Q

How are outbreaks identified?

A
  • Have to act on suspicion

- Typing necessary to determine if the same strain present i.e. an outbreak

31
Q

How can infections be typed?

A
  • Antiobiogram (antibiotic sensitivity pattern)
  • Phage typing (e.g. Staphylococcus aureus)
  • Pyocin typing (Pseudomonas)
  • Serotyping (Salmonella, Pseudomonas)
  • Molecular typing (DNA typing)
32
Q

What control measures are there for infection outbreaks?

A
  • Single room isolation
  • Cohorting of cases
  • Clinical Area/Ward Closure
  • Re-inforcement of IPC measures
  • Staff exclusion (e.g. colonised staff in case of MRSA; non-immune staff in case of VZV, measles etc.)
  • Staff decolonisation or other measures
33
Q

What are the clinical characteristics of C diff. infection?

A
  • Diarrhoea
  • Faeces have a characteristic odour
  • May have abdominal pain, pyrexia, raised white cell count
  • Pseudomembranous colitis (PMC)=most serious form
34
Q

Why is C.diff do prominent?

A
  • Part of the normal gut flora in ~2% adults
  • Carriage rate increases with age
  • ~30% elderly are colonised
  • Can survive in environment - importance of cleaning
35
Q

What does C.diff produce?

A
  • 2 toxins

- Toxin negative strains DO NOT cause disease

36
Q

Who are more susceptible to C. diff?

A

Elderly men

37
Q

What does C.diff cause?

A

Imbalance in gut flora

38
Q

How is C.diff infection diagnose?

A
  • Positive toxin test does not always mean disease

- Diarrhoeal symptoms NEED to be present for diagnosis of CDI

39
Q

Why does C. diff. infection still occur?

A
  • Not possible to prevent all cases
  • All antibiotics can predispose to CDI although some are more predisposing than others
  • New strains?
  • Less handwashing because more handgelling?
  • Environmental contamination may still be an issue?
  • Increased no. of vulnerable patients close together?
  • Increased throughput of patients?
  • Other drugs having an effect e.g. PPIs?
40
Q

What is the treatment for C.diff infection?

A

STOP THE ANTIBIOTICS PREDISPOSING TO C difficile IF POSSIBLE!

If symptomatic, treatment:

  • Oral metronidazole
  • Oral vancomycin if severe or failure to improve on metronidazole
  • Oral fidaxomicin if 2nd episode
41
Q

Use of what 4 antibiotics should be reduced to reduce C diff infections?

A
  • Ceftriaxone (other cephalosporin’s)
  • Co-amoxiclav
  • Clindamycin
  • Ciprofloxacin (Other quinolones)