Infection hazards in dentistry Flashcards
Name of e-learning programme for all healthcare professionals
Scottish Infection Prevention and Control Education Pathway
How many microorganisms per ml of saliva?
10^8
How many cultivable bacterial species are present in saliva?
350
What is a prion?
A misfolded protein that causes neurone degeneration in the brain
Disease caused by prions
vCJD
How is vCJD transmitted?
consumption of meat from cows with Bovine Spongiform Encephalopathy (BSE)
Impact of prions on clinical decontamination
Prions are resistant to steam sterilisation and radiation so instruments must be cleaned and sterilised.
Diseases caused by viruses
respiratory and blood borne infections
Droplet transmission definition
droplets of saliva and mucus (over 5 um) spread by coughs and sneezes
Airborne transmission definition
tiny particles less than 5um that are suspended in the air for longer and travel further than droplets
Aerosols vs droplets
aerosols remain suspended due to size/environment whereas droplets fall to a surface due to gravity/momentum of exhaled air
Factors that contribute to airborne transmission
poor ventilation, prolonged exposure, high confidence activities (generate more aerosols)
What evidence supports that COVID transmission was airborne not droplet?
Transmission rate is higher indoors and it is reduced by ventilation (doesn’t impact droplet transmission)
In 2021, the Scottish gov provided £5 mil for dentists to reach how many air changes per hour?
10 air changes per hour (was recommended in 2006!)
What may occupational asthma be caused by?
Exposure to contaminated dental unit waterlines (DUWL) containing bacterial endotoxin
What are endotoxins?
Lipopolysaccharide found in the outer membrane of gram negative bacteria
What is considered to be poor ventilation?
1-3 l/s/person
What is the desired ventilation?
8-10 l/s/person
the 3 Cs that increase transmission of respiratory viruses
crowding, closed setting, close contact
What are the benefits of ventilation?
improves health, concentration, sleep quality, environment, reduces absences and air pollutants.
Examples of blood borne viruses
hepatitis B and C
Why should antibiotics not be given for toothache?
only way to cure toothache is to drain pus and extract
Most common yeast infection in oral cavity
Candida albicans
2 types of oral candidiasis caused by Candida albicans
erythematous (red) candidiasis, pseudomembranous (false membrane) candidiasis
Name of new fungal superbug causing outbreaks in healthcare settings
candida auris
What is the hierarchy of controls for hazardous environments?
Most to least effective: elimination, substitution, engineering controls, administrative controls, PPE
Example of an elimination to control a hazardous environment
discontinued use of hazardous disinfectants. Safety syringes used to be most common sharps injury so they have eliminated the need to remove the needle.
What do engineering controls achieve?
Isolate people from the hazard
Examples of engineering controls
rubber dam, high volume aspiration, ventilation (extractor at foot of chair)
What are zoonotic diseases?
infectious diseases that can be transmitted from animals to humans.
Chain of infection model
mode of transmission -> portal of entry -> susceptible host -> infectious agent -> reservoir -> portal of exit
