L06 - Principles & Practice of Infection Control & Prevention

Question 1

Define a carrier

Answer 1

Person who harbours microbes with no signs of disease

Question 2

Define colonisation

Answer 2

Presence and multiplication without tissue invasion or damage

Question 3

Define infection

Answer 3

Entry and multiplication in tissues causing damage

Question 4

Define contamination

Answer 4

Soiling of objects with potentially infectious material

Question 5

Define a reservoir

Answer 5

A place where the micro-organism usually lives and reproduces

Question 6

Describe the six aspects of the Chain of Infection

Answer 6

Infectious Agent
Reservoir
Portal of Exit
Mode of Transmission
Portal of Entry
Susceptible Host

Question 7

Describe the two major routes of infection

Answer 7

Exogenous - from another person/the environment

Endogenous - self infection w/ own organisms

Question 8

Give three examples of exogenous routes of infection

Answer 8

Airborne (MTB, resp. virus, legionnaire’s)
Contact (staph, salmonella)
Percutaneous (needlestick, malaria)

Question 9

What host factors may predispose a person to infection?

Answer 9

Compromise of normal defences
Immunosuppression
Diabetes
Medical devices
Prolonged hospital stay/recurrent admissions
Intensive care
Prolonged broad-spectrum antimicrobials

Question 10

What is a nosocomial infection (HCAI)?

Answer 10

Hospital acquired
Occuring >48h after admission
Occuring <10d after discharge
Occuring <72h after out-patient procedure

Question 11

What are the five most common nosocomial infections?

Answer 11

UTIs
RTIs
Surgical wound infections
Line/device related infections
Diarrhoea (viral gastroenteritis, C. diff)

Question 12

Give six examples of ‘problem’ organisms

Answer 12

A/b resistant Gram-ve bacteria
MRSA
C. diff (norovirus)
Haemolytic streptococci
BBV
Vncomycin-resistant enterococci

Question 13

What are the most common multi-resistant Gram-ve organisms?

Answer 13

Coliform organisms
E. coli
Klebsiella spp.

Question 14

Describe the characteristics of the multi-resistant Gram-ve organisms

Answer 14

Resistant to beta-lactams (by multiple enzymes) and other antimicrobials
Resistance may be transferable (via plasmids)
Carbapenems are stable, often last line of defence

Question 15

Give four examples of ways to remove exogenous sources of infectious agents

Answer 15

Good hygiene/cleaning
Maintenance of cooling towers/water supplies
Clean/sterile equipment
Food safety

Question 16

Give four examples of ways to block transmission of infectious agents

Answer 16

Protective clothing
Isolation
Aseptic procedures
Hand washing/alcohol gel

Question 17

By how much can high standards of hygiene, appropriate use of devices and rational use of antibiotics reduce HCAI by?

Answer 17

20-30%