Theme 3 Lecture 23: Infection Prevention and control Flashcards
Describe the cycle of infection
- Pathogenic organism (of sufficient virulence and in adequate numbers to cause disease)
- Reservoir (that allows organism to survive and multiply)
- Exit (mode of exit from source)
- Transmission (from source to host)
- Entry (of pathogen into host)
- Susceptible host (i.e non-immune)
Explain the cycle of infection for MRSA
- Pathogenic organism: MRSA
- Reservoir: human skin particularly nose and other moist/hairy areas
- 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
What 3 situations define an outbreak?
- two or more linked cases of the same illness
- when the observed number of cases exceeds the expected number
- single case of disease caused by a specific pathogen
Which viruses commonly cause outbreak in hospitals?
- influenza
- norovirus (“vomiting disease”)
- SARS CoV-2
Which bacteria commonly cause outbreak in hospitals?
- C.difficile
- MRSA
- group A streptococcus
- VRE (vancomycin resistant enterococci)
- multi drug resistant gram -ves (ESBL, CPEs)
which fungi commonly cause outbreaks in hospitals?
aspergillus
How do we prevent the spread of MRSA?
- Pre-operative screening +/- decolonisation
2. Perioperative antibiotics - with activity against MRSA if knownn positive
Where are patients screened for MRSA?
Nose, axilla, groin
What are some IPC techniques to minimise the spread of infections in surgery?
- surgical skin prep
- scrub technique and hand hygiene
- ventilation of operating 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 and what are the two main methods?
- disinfection reduces micro-organisms to a level at which they are not harmful
- two main methods are heat disinfection (e.g dishwasher) or chemical disinfection (e.f chlorine)
What is cleaning?
removal of dirt, dust and any organic matter using water and detergent
What is sterilisation?
destroys all micro-organisms including spores
What are the methods of sterilisation?
- Heat
- moist: autoclave - delivery of steam under high pressures
- dry: oven - Chemical
- gas,liquid - Filtration
- Ionising radiation
- for single use disposable equipment
Which is the least hazardous method of decontamination (and therefore should be used where possible)?
heat
Which methods should be used for items/devices that will contact mucous membranes or that will be contaminated with body fluids?
disinfect
Which methods should be used for items/devices that will enter sterile body areas or break the skin?
sterilise
Which methods should be used for items/devices that only contact intact skin?
clean
How would a blood pressure cuff be decontaminated?
cleaned only
How would surgical instruments be decontaminated?
- sterilisation
- by mois heat
How would the central venous catheter (CVC) insertion site be decontaminated?
- disinfected (antisepsis)
- by chemicals
What are post-operative interventions for IPC?
- wound care
- hand hygiene
- PPE
- clinical waste disposed of
- decontamination of medical equipment
- environmental cleaning and decontamination
- patient placement - MRSA +ve patients should be nursed in a single room with en suite toilet facilities
What two types of bacteria do we carry on our hands?
- resident bacteria - deep seated, difficult to remove
2. transient bacteria - easily picked up, transferred, removed
What are the 5 moments for hand hygiene at the point of care?
- before patient contact
- before aseptic task
- after body fluid exposure risk
- after patient contact
- after contact with patient surroundings
What is antisepsis?
disinfection applied to damaged skin or living tissues - it requires a disinfectant with minimal toxicity
