L37 Hospital Acquired Infections

Question 1

The rabbit test and the limulus amoebocyte lysate (LAL) test are used to check for what?

Answer 1

Viable pyrogens

Pyrogens cause fevers

Question 2

What is ‘the bioburden’?

Answer 2

The bioburden is the total load of viable microorganisms present in a product to be sterilised

Question 3

What is the aim of sterilisation, with reference to the bioburden?

Answer 3

Reduce bioburden to 10^-6 organisms per container.

Means the chance of having a positive container is 1 in a million

Question 4

What do you need to know in order to calculate how long sterilisation will take?

Answer 4

• The bioburden

- The D-value of a resistant organism

Question 5

With regards to sterilisation, what is the D-value

Answer 5

The D value (for a thermal process) is the time taken at a fixed temperature required to achieve a 90% reduction in the micro-organism population.

Question 6

True or false: Alcohol handrubs and gels are not effective against C. difficile spores

Answer 6

True

Question 7

How can you measure the bioburden on a surface?

Answer 7

Luciferase enzyme reacts with ATP to produce light.

ATP Assay Device takes 3 seconds to read the bioburden.

Question 8

What methods are used to decontaminate whole rooms?

Answer 8

• Hydrogen peroxide vapour

- UV light