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Flashcards in Healthcare Acquired Infeciton Deck (32)
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1
Q

What are healthcare acquired infections?

A

Healthcare Associated Infections (HAI) are:

– 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

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

3
Q

What are the common sites for healhcare associated?

A

UTI - mainly related to catheterisation

Surgical Site Infection

Respiratory tract infection (related to intubation)

Bloodstream infections - mainly central venous catheter related

GI infection

Skin and soft tissue infection

4
Q

What are nature’s defence mechanisms?

A

Intact skin

Bacterial flora on the skin and the GIT

Body secretions (tears containing antibodies / enzymes, coughing)

Gastric acid

Flushing (urination)

2nd line defence (immune system)

5
Q

Colonisation of the nose with staph aureus is said to be as common as 30% in the population. Describe the sensitivity of the staph aureus?

A

¨Most colonised with the METICILLIN SENSITIVE Staphylococcus aureus (MSSA)

6
Q

How can the colonising staph aureus 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)

7
Q

Disturbance in bacterial-host equilibrium leads to most HAI

A
8
Q

What microbial factors can increase the chances of infection?

A

Increased:

  • Resistance
  • Virulence (the severity or harmfulness of a disease or poison)
  • Transmissability
  • Increased survival ability
  • Ability to evade host defences
9
Q

What are the host factors that can increase the chances of 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!!!

10
Q

What is the chain of infection

A

Source of microbe (endogenous or exogenous)

Transmission

Host

11
Q

What are the modes of transmission and give an example of each

A

Direct contact - staph aureus and coliforms

Respiratory / droplet - Neisseria meningitidis, mycobacterium TB

Faecal oral route - clostridium difficile, salmonella sp

Penetrating injury - group A streptococcus, bloodbourne viruses

12
Q

How do we break the chain of infection?

A

Risk awareness

Standard Infection Prevention and Control Precautions (SICPs)

Hand Hygiene

Appropriate PPE

Vaccination

Post Exposure Prophylaxis

Environment

13
Q

What is cleaning, disinfection and sterilisation?

A

Cleaning: Physical removal of organic material and decrease in microbial load

Disinfection: Large reduction in microbe numbers - spores may remain

Sterilisation: Removal/Destruction of ALL microbes and spores

14
Q

What items are cleaned, disinfected and sterilised?

A

Low risk = cleaning

Intact skin contact e.g.

stethoscopes, cots,

Mattresses

Medium risk = Disinfection or sterilisation as appropriate

Mucous membrane

contact e.g. bedpans,

vaginal specula,

Endoscopes

High Risk = Sterilisation

e.g. surgical instruments

15
Q

Cleaning is often required before sterilisation and disinfection

Drying is an important part of the process

A
16
Q

What are the methods of disinfection?

A

Heat

–Pasteurisation (e.g. bedpans, linen, dishwashers)

–Boiling (vaginal specula, ear syringes)

Chemical

–Chemicals vary in their organism activity range

–Needs to be equipment compatible

–Examples: Alcohol, chlorhexidine, hypochlorites, hydrogen peroxide

17
Q

What are methods of sterilisation?

A

Steam under hot pressure (autoclave)

Hot air oven

Gas (ethylene dioxide)

Ionising radiation

18
Q

Surveillance

A

Local Surveillance:

–Laboratory Based

–Ward/Clinical Area Based

National Surveillance

19
Q

What does IPCT stand for?

A

Infection prevention and control team

20
Q

Local surveillance can either be lab based or clinical area based, what is the advantages and disadvantages of each?

A

Laboratory detects an organism and notifies IPCT and clinicians Advantages = know what organism is and specific recommendations can be made.

Disadvantages = depends on samples being sent, time taken to detect organism, tests not 100% accurate

Clinical area staff notify infection prevention and control team (IPCT)

Advantgaes - detect potential problem sooner, can ensure correct samples sent

Disadvantages - causative microbe not konwn, IPC measure need to be more general

21
Q

What is the definition of an outbreak?

A

2 or more cases of an infection linked in time and place

22
Q

What is the purpose of IPCT?

A

Prevent individual infections and outbreaks

23
Q

What is the purpose of surveillance?

A

To detect and identify a possible outbreak at the earliest opportunity

24
Q

Why is typing necessary?

A

To determine if the same strain present - (assessing if infections are linked and therefore classed as an outbreak)

25
Q

What are the methods of typing?

A

Antiobiogram (antibiotic sensitivity pattern)

Phage typing (e.g. Staphylococcus aureus)

Pyocin typing (Pseudomonas)

Serotyping (Salmonella, Pseudomonas)

Molecular typing (DNA typing)

26
Q

What are control measures for outbreaks?

A

Single room isolation

Cohorting of cases

Clinical area/ward closure

Re-inforcement of IPC measures

Staff exclusion (colonised staff in case of MRSA, non-immune staff in the case of VZV, measles etc)

Staff decolonisation or other measures

So there are changes to the ward (it closes and people are kept in isolation)

There are changes to the staff (exclusion and decolonisation)

And cohorting of cases

27
Q

What are the characteristic clinical features of c difficile?

A

Diarrhoea

Faeces have a characteristic odour

May have abdominal pain, pyrexia, raised white cell count

Pseudomembranous colitis (PMC)

28
Q

How common is c Diff in the population?

A

Part of the normal gut flora in ~2% adults

Carriage rate increases with age

30% elderly are colonised

29
Q

What causes c diff infection?

A

Imbalance in gut flora

Endogenous and exogenous source

2 toxins are produced - toxin negative strains do not cause disease

30
Q

What is required for diagnosis of c diff?

A

Positive Toxin Test DOES NOT ALWAYS MEAN DISEASE!

Diarrhoeal symptoms need to be present for diagnosis of CDI!

31
Q

What are factors increasing the likelihood of cdiff infection?

A

Antibiotics - all can predispose to CDI although some are more predisposing than others

Less handwashing because more handgelling

Other drugs having an effect such as PPIs

32
Q

What is the treatment for CDiff?

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 (Scottish Medicines Consortium (SMC) Guidance 2012)

N.B. DO NOT TREAT THE SYMPTOM FREE!

Any antibiotic can cause CDI including Metronidazole and Vancomyin