Lecture 5: Control Of Microorganisms: Infection Control, Sterilization, And Disinfection

Question 0

What category of precautions is used whenever potential exposure to blood or body fluids exists? This includes clean hands, covering mouth, gown and gloves, and eye protection

Answer 0

Standard precaution

Question 1

What are the steps in the chain of infection?

Answer 1

TRANSMISSION occurs when:
Agent leaves its RESERVOIR (host) through PORTAL OF EXIT
Conveyed by some MODE OF TRANSMISSION
Enters SUSCEPTIBLE HOST through PORTAL OF ENTRY

Question 2

What category of precaution is taken for microorganisms smaller than 5microns?

Answer 2

Airborne (respiratory) precautions

Question 3

What are examples of airborne/respiratory precautions?

Answer 3

N95 mask and gown
Private negative pressure room
Surgical masks

Question 4

What size are droplets?

Answer 4

Larger than 5microns

Question 5

MRSA, VRE, resistant Acinetobacter, ESBL gram negatives (multi-drug resistant), rotavirus, and scabies require what kinda of precautions?

Answer 5

Contact precautions

Question 6

Are alcohol based hand washing products allowed for contact precautions?

Answer 6

Yes

Question 7

What category of precautions includes c-Diff, acute diarrhea with recent antibiotic use or infectious cause, norovirus/rotovirus, and enteric infections (campylobacter, cryptosporidium, salmonella, shigella, E. Coli)?

Answer 7

Contact PLUS

Question 8

Are alcohol based hand washing products allowed with contact PLUS precautions?

Answer 8

No

Question 9

Why is reverse/protective isolation used?

Answer 9

Protect patient with compromised health from contamination

Mask, gloves, gown

Question 10

What does sterilization do?

Answer 10

Eliminates all forms of microbial life

Question 11

Can human tissue be sterilized?

Answer 11

No

Question 12

What does disinfection do?

Answer 12

Eliminates all pathogenic microorganisms

Question 13

What can’t disinfection eliminate?

Answer 13

Bacterial spores

Inanimate objects

Question 14

What do three levels of disinfection represent?

Answer 14

Number of organisms eliminated
Required strength
(High, intermediate, low)

Question 15

What does antisepsis do, and where does it work?

Answer 15

Reduce microorganisms on living tissue/skin
Body surfaces
Internally (orally, urinary tract)
Externally (body surface)
On inanimate objects

Question 16

What can’t antiseptics do?

Answer 16

Kill spores

Be used as disinfectants (don’t eliminate all pathogens)

Question 17

What characterizes critical items for disinfection and sterilization?

Answer 17

Enter normally sterile parts of body

Question 18

Critical items require which method of infection control? What kind of methods are used?

Answer 18

Sterilization by physical methods

Question 19

What characterizes semi critical items?

Answer 19

Come in contact with mucous membranes or non intact skin

Question 20

What type of infection control method do semi critical items require?

Answer 20

High level disinfectant

Question 21

How are noncritical items characterized?

Answer 21

Come in contact with skin but not mucous membranes

Question 22

What compounds can be used for infection control of noncritical items?

Answer 22

Alcohols, phenolics, halogens, quaternary ammonium compounds

Question 23

What is the most widely used method for sterilizing inanimate objects and why?

Answer 23

autoclaving
Highly effective
Quick

Question 24

Which physical sterilization technique is used for products which contain petroleum based liquids or could corrode or rust?

Answer 24

Dry heat sterilization

Question 25

How are single use medical supplies sterilized?

Answer 25

Gamma irradiation

Question 26

How are liquids which contain proteins, or other delicate compounds, sterilized?

Answer 26

Filtration (size-exclusion)

Question 27

What type of physical sterilization is used for porous items?

Answer 27

Gas sterilization

Question 28

What is an example of a volatile gas used in gas sterilization?

Answer 28

Ethylene oxide

Question 29

What are the advantages of plasma sterilization?

Answer 29

High penetration of medical lumens (tubes - endoscopes) No residual activity Quick Can be kept next to procedure

Question 30

How does plasma sterilization work?

Answer 30

Enclosed chamber. Radio frequency or microwave energy is used to excite gas molecules of H2O2 or per-CH3COOH. Produces charged particles - free radicals. Disrupts the metabolism of microorganisms

Question 31

For what level disinfection are alcohols appropriate?

Answer 31

Intermediate and low level disinfection

Question 32

Do alcohols kill viruses?

Answer 32

MOST viruses

Question 33

Which halogenic compound can kill spores and TB at higher concentrations?

Answer 33

Chlorine/chlorine releasing compounds

Question 34

Do chlorine compounds kill viruses?

Answer 34

Yes

Question 35

What halogenic compounds are used for antisepsis of skin, mucous membranes, and wound sites? Give an example of a product.

Answer 35

Iodine and iodophors | Betadine (PVP)

Question 36

Which compound prevents regrowth of microorganisms for up to 6 hours?

Answer 36

Chlorohexidine

Question 37

pHisoHex is what kind of halogenic compound? What is it used for?

Answer 37

Phenolic compound | Showering before surgery

Question 38

Pine sol is an example of what type of halogenic compound?

Answer 38

Phenolics

Question 39

Which phenolic derivative has strong bacteriostatic action against G+ organisms (like staphylococci) but not many G-?

Answer 39

Hexachlorophine

Question 40

Which type of halogenic compounds are characterized as follows: Lethal except to endospores, TB, and non-enveloped viruses Surfactants, detergent activity Antimicrobial and disinfectant

Answer 40

Quaternary ammonium compounds

Question 41

Benzalkonium chloride is an example of what class of halogens?

Answer 41

Quaternary ammonium compounds

Question 42

What two alloy surfaces are used in infection control?

Answer 42

Silver and copper

Question 43

Which alloy surface kills 99.9% of G+ and G- bacteria within 2 hours of exposure?

Answer 43

Copper

Question 44

E. coli strains, MRSA, vancomycin-resistant enterococci (VRE), C-Diff, influenza A, adenovirus, and fungi are killed by which alloy surface?

Answer 44

Copper