Infection hazards in dentistry

Question 1

Name of e-learning programme for all healthcare professionals

Answer 1

Scottish Infection Prevention and Control Education Pathway

Question 2

How many microorganisms per ml of saliva?

Answer 2

10^8

Question 3

How many cultivable bacterial species are present in saliva?

Answer 3

350

Question 4

What is a prion?

Answer 4

A misfolded protein that causes neurone degeneration in the brain

Question 5

Disease caused by prions

Answer 5

vCJD

Question 6

How is vCJD transmitted?

Answer 6

consumption of meat from cows with Bovine Spongiform Encephalopathy (BSE)

Question 7

Impact of prions on clinical decontamination

Answer 7

Prions are resistant to steam sterilisation and radiation so instruments must be cleaned and sterilised.

Question 8

Diseases caused by viruses

Answer 8

respiratory and blood borne infections

Question 9

Droplet transmission definition

Answer 9

droplets of saliva and mucus (over 5 um) spread by coughs and sneezes

Question 10

Airborne transmission definition

Answer 10

tiny particles less than 5um that are suspended in the air for longer and travel further than droplets

Question 11

Aerosols vs droplets

Answer 11

aerosols remain suspended due to size/environment whereas droplets fall to a surface due to gravity/momentum of exhaled air

Question 12

Factors that contribute to airborne transmission

Answer 12

poor ventilation, prolonged exposure, high confidence activities (generate more aerosols)

Question 13

What evidence supports that COVID transmission was airborne not droplet?

Answer 13

Transmission rate is higher indoors and it is reduced by ventilation (doesn’t impact droplet transmission)

Question 14

In 2021, the Scottish gov provided £5 mil for dentists to reach how many air changes per hour?

Answer 14

10 air changes per hour (was recommended in 2006!)

Question 15

What may occupational asthma be caused by?

Answer 15

Exposure to contaminated dental unit waterlines (DUWL) containing bacterial endotoxin

Question 16

What are endotoxins?

Answer 16

Lipopolysaccharide found in the outer membrane of gram negative bacteria

Question 17

What is considered to be poor ventilation?

Answer 17

1-3 l/s/person

Question 18

What is the desired ventilation?

Answer 18

8-10 l/s/person

Question 19

the 3 Cs that increase transmission of respiratory viruses

Answer 19

crowding, closed setting, close contact

Question 20

What are the benefits of ventilation?

Answer 20

improves health, concentration, sleep quality, environment, reduces absences and air pollutants.

Question 21

Examples of blood borne viruses

Answer 21

hepatitis B and C

Question 22

Why should antibiotics not be given for toothache?

Answer 22

only way to cure toothache is to drain pus and extract

Question 23

Most common yeast infection in oral cavity

Answer 23

Candida albicans

Question 24

2 types of oral candidiasis caused by Candida albicans

Answer 24

erythematous (red) candidiasis, pseudomembranous (false membrane) candidiasis

Question 25

Name of new fungal superbug causing outbreaks in healthcare settings

Answer 25

candida auris

Question 26

What is the hierarchy of controls for hazardous environments?

Answer 26

Most to least effective: elimination, substitution, engineering controls, administrative controls, PPE

Question 27

Example of an elimination to control a hazardous environment

Answer 27

discontinued use of hazardous disinfectants. Safety syringes used to be most common sharps injury so they have eliminated the need to remove the needle.

Question 28

What do engineering controls achieve?

Answer 28

Isolate people from the hazard

Question 29

Examples of engineering controls

Answer 29

rubber dam, high volume aspiration, ventilation (extractor at foot of chair)

Question 30

What are zoonotic diseases?

Answer 30

infectious diseases that can be transmitted from animals to humans.

Question 31

Chain of infection model

Answer 31

mode of transmission -> portal of entry -> susceptible host -> infectious agent -> reservoir -> portal of exit