sterilisation and infection prevention

Question 1

what are the 3 main types of transmission of organisms

Answer 1

contact (direct and indirect)
airborne
droplet

Question 2

which pathogens can be transferred from direct person to person contact

Answer 2

scabies

HSV

Question 3

what is the difference between droplet and airborne pathogens

Answer 3

• droplet >5microns - drop to the ground by ~1m

- airborne <5microns - stay in the air

Question 4

which pathogens are considered to be spread by droplets

Answer 4

influenza
pertussis
SARS
neisseria m.
rhinovirus

Question 5

which pathogens are considered to be spread by the airborne route of transmission

Answer 5

TB
measles
varicella
measles

Question 6

what are the 4 types of isolation precautions

Answer 6

standard precautions
contact precautions
droplet precautions
airborne precautions

Question 7

when are standard precautions used

Answer 7

used for all patients at all times regardless of patient diagnosis or presumed infectious status

Question 8

what is standard precautions

Answer 8

gloves, gowns, goggles/face shield when working with body fluids, non-intact skin and mucous membranes

Question 9

what do you do for contact precautions

Answer 9

• using gowns and gloves for all patient contact

- patient in a single room

Question 10

which types of diseases would you do contact precautions

Answer 10

• diarrhoea
• excessive wound drainage
• multidrug resistant organisms
• respiratory viruses

Question 11

what do you do for droplet precautions

Answer 11

• using surgical masks for all patient contact

- single room for patient

Question 12

what do you do for airborne precuations

Answer 12

• negative pressure ventilation room

- N95 mask for all patient contact

Question 13

what is the definition of sterilisation

Answer 13

the process of killing or removing all viable organisms, including viruses, bacteria, fungi and spores

Question 14

what is the definition of disinfection

Answer 14

the process that eliminates many or all pathogen microorganisms on inanimate objects with the exception of bacterial spores

Question 15

what is the definition of cleaning

Answer 15

the removal of visible soil from objects and surfaces

Question 16

what is the spaulding classification

Answer 16

a classification of objects into critical, semicritical and noncritical disinfection depending on the objects use

Question 17

which objects are “critical”

Answer 17

those that enter normally sterile tissue –> need to be sterile

Question 18

which objects are semicritical

Answer 18

objects that touch mucous membranes or skin that is not intact –> need to be disinfected

Question 19

which objects are noncritical

Answer 19

objects that touch only intact skin –> require low level disinfection only

Question 20

what do you use to sterilise an object

Answer 20

• usually steam

- for heat sensitive objects - other ways (hydrogen peroxide etc)

Question 21

what is asepsis

Answer 21

free from infection or infectious material

Question 22

what is ANTT

Answer 22

a technique used to prevent contamination of equipment and skin breaches by microorganisms that could cause infection

Question 23

what is in skin preps

Answer 23

combination of alcohol and chlorhexidine or alcohol and iodine

Question 24

what is the difference in action between chlorhexidine and iodine

Answer 24

chlorhexidine is not inactivated in the presence of organic material, while iodine is

Question 25

what is the most common source of nocosomial infection

Answer 25

patients own microbiota

Question 26

what is sterility assurance

Answer 26

the probability that the instrument is sterile

Question 27

What is the D value for a sterilisation procedure

Answer 27

the rate of kill - the time to reduce microbiota population 10 fold

Question 28

what is the antibiotic that is used as a surrogate for methicillin for "methicillin resistance testing"

Answer 28

cefoxitin

Question 29

what are the most common organisms causing endocarditis

Answer 29

``` staph aureus strep viridans enterococci strep pyogenes staph epididermis ```

Question 30

which patients are the most susceptible to endocarditis

Answer 30

those with damaged valves

Question 31

what four things do you need to know to design an appropriate sterilisation process for a particular instrument

Answer 31

- type and level of contamination - rate of biocidal action of agent (D value) - level of sterility assurance required - will the item survive the process

Question 32

why does a patient develop pseudomonas colitis

Answer 32

AB treatment --> kills rest of the microbiota in the gut --> then able to grow and produce toxins --> mucosal damage

Question 33

which nosicomial organisms respond well to alcohol-based hand hygiene programs, and which do not

Answer 33

``` do = MRSA and gram-negative infections don't = C. difficile, pseudomonas ```

Question 34

what is the thought around the source of VRE

Answer 34

- about half arise de novo by microbiota passing on Tn1540 (Resistance plasmid) - direct patient contact