Infection Prevention and Control Flashcards
(35 cards)
Retrospective vs prospective study?
In prospective studies, individuals are followed over time and data about them is collected as their characteristics or circumstances change.
In retrospective studies, individuals are sampled and information is collected about their past.
i.e. Retrospective (look back exercise). Prospective (more tests, awareness).
What are the 6 steps in the chain of infection?
- Pathogenic organism: Of sufficient virulence and in adequate numbers to cause disease
- Reservoir: Reservoir or source that allows the organism to survive and multiply
- Exit: Mode of exit from the source
- Transmission: Mode of transmission from the source to the host
- Entry: Portal of entry through which the pathogen can enter the host
- Susceptible host (i.e. non-immune)
Fill out the 6 steps in the chain of infection for MRSA:
- Pathogenic organism: MRSA
- Reservoir: Human skin particularly nose and other moist and hairy areas
3, 4, 5. Mode of transmission, exit and entry: direct contact with infected sites or indirect contact with fomites or hands of healthcare workers
- Susceptible host: any breakdown in skin integrity
Where is MRSA normally found?
Human skin particularly nose and other moist and hairy areas
What is the aim of infection prevention and control (IPC)?
Activities undertaken with the aim of breaking the chain of infection e.g.:
- Eliminate pathogenic organism
- Remove source/reservoir
- Minimise transmission
- Eliminate exit and entry
- Reduce susceptibility to infection
What is ‘phage typing’? What is it used for?
Phage typing is a method used for detecting single strains of bacteria. It is used to trace the source of outbreaks of infections.
What is an outbreak?
Two or more linked cases of the same illness, when the observed number of cases exceeds the expected number or a single case of disease caused by a significant pathogen (i.e. viral haemorrhagic fever)
An outbreak investigation is then needed to determine mode of transmission and any breakdown in IPC practices.
Which viruses commonly cause outbreaks in hospitals?
Influenza
Norovirus
SARS CoV-2
Which bacteria commonly cause outbreaks in hospitals?
Clostridium difficile MRSA Group A Streptococcus VRE (vancomycin resistant Enterococci) Multi drug resistant gram negatives ( ESBL, CPEs)
Which fungi commonly cause outbreaks in hospitals?
Aspergillus
All elective surgical patients should be screened for MRSA pre surgery.
- Where are swabs taken from?
- If positive, what happens?
- nose, axilla and groin
2. Offered decolonisation if positive – mupirocin or neomycin and chlorhexidine body wash
What perioperative measures are taken to prevent infection?
Perioperative antibiotics (with activity against MRSA if known positive)
Surgical skin prep
Scrub technique and hand hygiene
Ventilation of operative theatre
Clinical waste
Environmental cleaning and decontamination
Sterilisation of equipment
What is decontamination?
A combination of processes that removes or destroys contamination so that infectious agents or other contaminants cannot reach a susceptible site in sufficient quantities to initiate infection, or other harmful response.
What is disinfection?
Reduces micro-organisms to a level at which they are not harmful.
What are the 2 main methods of disinfection?
- Heat disinfection e.g. dishwasher, bed pan washer;
2. Chemical disinfection e.g. endoscope washer/disinfector, chlorine-releasing agent for cleaning equipment.
What is cleaning?
The removal of dirt, dust or any organic matter using water and detergent.
About 80% of micro-organisms will also be removed if the item is dried, therefore drying is an important part of the process.
What is sterilisation?
Sterilisation destroys all micro-organisms including spores.
What methods of sterilisation are there?
- Heat
- Moist: autoclave: Delivery of steam under high pressure. Specific pressure and temperatures
- Dry: oven: Controlled temperature cycles (i.e. 160oC for 2 hours or 170oC for 1hour) - Chemical: Gas, liquid
- Filtration
- Ionising radiation
What is ionising radiation used to sterilise?
Used for single use disposable equipment
What is the preferred method of sterilisation?
Heat by autoclave
What factors determine the method of decontamination used?
Risk of infection (high, intermediate, low)
Physical properties: Item, Packaging materials
Decontamination level: Sterilisation, disinfection (antisepsis), cleaning, disposal
Which method of decontamination is the least hazardous?
Heat is the least hazardous method and should be used where possible
What is chemical disinfection is largely limited to?
Environmental decontamination (surfaces, spills etc.)
Antisepsis
Heat-sensitive items
Which method is used to decontaminate items/devices that will enter sterile body areas or break the skin?
STERILISE