M: Sterilization, Disinfection, Infection Control - Week 8 Flashcards
What do ‘aseptic technique’ and ‘infection control’ involve?
Aseptic technique: involves using procedures to minimise the transfer of microorganisms
Infection control: involves the prevention or minimisation of cross infections
How do cross infections spread? (3)
- patient to staff
- staff to patient
- patient to patient
How can infections be spread? (3)
- direct contact
- aerosol
- instrument/equipment
When may optometrists be exposed to blood, tears and mucous membranes? (5)
When:
- remove a foreign body
- assessing patients with ocular trauma, conjunctivitis or microbial keratitis
- carrying out lacrimal lovage
- expressing glands and cysts
- fitting contact lenses
List 8 communicable diseases that could potentially be passed from patient to optometrist:
- HIV/AIDS
- Hep B and C
- TB
- Measles, mumps, rubella, chicken pox
- infectious mononucleosis
- herpes, influenza
- Adebovirus 8
- CID
Define the following:
A) cleaning
B) disinfection
C) sterilisation
A: removal of contaminating matter to reduce burden of organic material
B: removing from an article some or all of its burden of pathogenic microorganisms
C: destruction or removal of all viable microorganisms, spores and other infectious agents from an article
Explain the 3 classifications found in the Spaulding classification system of equipment uses
- Critical: invasive devices that enter normally sterile tissue or enter the vascular system by intent or accident
2: device contacts but does not penetrate mucous membrane
3: Device only contacts intact skin
List 3 factors that influence decision making in regards to whether to sterilise or disinfect
- risk and cost/benefit analysis
- Common sense
- Lobby groups (susceptible hosts)
What do you need to ensure a sterilisation/disinfection process is efficient? (3)
- Appropriate agent
- Appropriate conditions
- Appropriate apparatus (to ensure effective contact between agent and microorganisms)
What information do you need to design a sterilisation/disinfection process? (3)
- initial contamination level
- rate of biocidal action of agent
- sterility assurance required
Explain the process of obtaining a ‘Viable Count’ (5)
- prepare dilutions of sample
- spread on agar plates
- incubate plates
- count colonies
- estimate microbial load (one colony = one bacterial cell)
What does the D value represent?
The amount of time required to kill 90% of the organisms in a sample (ie a 10-fold reduction)
Define sterility assurance
A calculated probability that a microorganism could survive a sterilisation process and thereby render a proportion of treated articles unsterile
Name the 4 main methods of sterilisation
- Heat
- Filtration
- Ionising radiation
- Use of chemicals
Which heat is more effective at sterilisation: moist or dry?
Moist heat