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Flashcards in Infection Control (complete) Deck (64):
1

Which are ways that infection may spread in a dental clinic

1. airborne organisms
2. improper sterilization
3. Direct contact
4. Indirect contact

2

According to Spauldings classifications, When is an instrument needing critical disinfection? and what is the process of disinfection

Critical is when equipment has entered sterile tissues, including the vascular system
They need cleaning followed by sterilization

3

According to Spauldings classifications, When is an instrument needing Semi-critical disinfection? and what is the process of disinfection

Semi-critical is when equipment comes into contact with non-intact skin or mucus membranes, but hasn't penetrated them
They need cleaning, with high level disinfection as a minimum. (sterilization is preferred)

4

According to Spauldings classifications, When is an instrument needing non-critical disinfection? and what is the process of disinfection

Equipment that touches intact skin, or doesn't touch the patient
the need cleaning, followed by low level disinfection (some cases cleaning alone is acceptable)

5

What is sterilization

the complete absence of life

6

what is disinfection

destruction of vegetative pathogens, usually on inanimate objects

7

What does the suffix - cides mean

agents that kill

8

what does the suffix - static mean

agents which prevent growth

9

What is sepsis

bacterial contamination and growth

10

What is antiseptic

agent which destroys vegetative pathogens (usually on living tissue)

11

What is sanitation

Lowering bacterial counts to safe public health levels

12

is the death rate of microbes log linear

yes, a certain percentage of the bacteria die over time

13

what is D-value (death of microbes)

the time required to kill 90% of bacteria (1 log) at a specific temperature

14

How do log reduction and percent kill relate

for each log reduction 90% of the bacteria are killed
1 log = 90%
2 log = 99%
3 log = 99.9%
4 log = 99.99%

15

Which is better at disinfecting, sanitizing, and sterilizing: Moist heat or Dry heat

moist heat (dry heat requires longer time, and higher temperatures)

16

how does heat kill bacteria

by denaturing proteins and destroying cytoplasmic membranes

17

What are the four methods of microbial control that use moist heat

1. boiling
2. autoclaving
3. pasteurization
4. Ultra-high temperature sterilization

18

What can boiling kill in terms of microbes

vegetative cells of bacteria and fungi
viruses
protozoan trophozoites

19

What is important to consider when boiling to kill microbes

the boiling time (more time if at higher locations

20

What can't boiling kill in terms of microbes

endospores
protozoan cysts
prions

21

What is autoclaving

when pressure is applied to boiling water, which prevents the escape of steam. this leads to increased temperature (121 C)

22

Does autoclaving kill endospores

yes

23

What is historical (batch) pasteurizaition

heating up something to 63 degrees celcius for 30 minutes

24

What is flash pasteurization

72 degrees celcius for 15 seconds

25

When do you use dry heat to sterilize

when you have materials that will be damaged by moist heat, or those that can't be sterilized with moist heat

26

what is the ultimate means of sterilization

incineration

27

What is membrane filtration

running a liquid medium through a filter with specific pore sizes to trap desired organisms

28

What is ionizing radiation, and how does it kill bacteria

shooting wavelengths of less than 1nm, it disrupts bonding, and creates ions that denature DNA and other molecules

29

how effective is ionizing radiation against bacteria

it isn't very effective, it is more lethal to humans than to bacteria

30

what is non-ionizing radiation

radiation with wavelengths greater than 1 nm.

31

what is non-ionizing radiation used for

disinfecting air, transparent fluids, and surfaces of objects

32

How does contact time affect disinfection

longer time = more effective

33

how is disinfection affected by Temperature

hotter = more effective

34

how is disinfection affected by pH

dependent on each chemical

35

how is disinfection affected by Bioburden

more microbes = need a longer time

36

how is disinfection affected by Extraneous matter

organic matter inhibits many disinfectants

37

how is disinfection affected by proper exposure

it insures the agent gets in

38

how is disinfection affected by disinfectant concentration

higher = better, with alcohols as the exception

39

List these from least to most resistant to disinfection
spores
fungi
mycobacteria
non-enveloped viruses
enveloped viruses
gram positive bacteria
gram negative bacteria
prions

envelopped viruses and gram positive bacteria
fungi and gram negative bacteria
non-enveloped viruses
spores and mycobacteria
prions

40

What are the characteristics in the disinfectants with phenol (phenolics)

- intermediate to low level disinfectants
- Denatures proteins and disrupt cell membranes
- remain active for a long time
- ineffective against many naked viruses

41

What are the characteristics of alcoholic disinfectants

- intermediate level disinfectants
- denature proteins and disrupt cytoplasmic membranes
- evaporate rapidly
- good surface disenfectants
- no activity on spores

42

do alcohols have activity against spores

nope

43

do isopropyl alcohol inactivate naked viruses

nope

44

What are the characteristics of halogen disinfectants

intermediate-level antimicrobial chemicals
damage via oxidation, or denaturing proteins
iodine tablets, iodophors, chlorine, bromine

45

What easily inactivates halogen disinfectants

organic material

46

What are the characteristics of oxidizing agents as disinfectants

high-level disinfectants
kill via oxidation
hydrogen peroxide, ozone, peracetic acid

47

what is peracetic acid particularly effective against

spores, used to sterilize equipment

48

What are the characteristics of surfactants as disinfectants

reduce surface tension of solvents to make them better at dissolving solutes
soaps, detergents, and quats

49

Where are quats used, and what type of disinfectant are they

they are surfactants, and they are used in medical, food, and industrial applications

50

What are the characteristics of heavy metals as disinfectants

alter the 3-D shape of proteins
low level bacteriostatic and fungistic agents
1% silver nitrate used to prevent blindness (gonorrhea)
copper used to control algal growth

51

What are the characteristics of aldehydes as disinfectants

cross link groups to denature proteins and inactivate nucleic acids
glutaraldehyde both disinfects, and sterillizes (long exposure)
formalin used in embalming and disinfection

52

What are the characteristics of gaseus agents as disinfectants

denature proteins by cross linking functional groups
used in hospitals and dental offices
can be hazardous, carcinogenic, poisonous, and flammable

53

Does cellulose in paper towels inactivate iodophores

Yes

54

Does the glutaraldehyde used in hospitals do a good job of killing HPV

nope

55

What kind of filters are used to filter microbes out of the air

HEPA filters

56

What is the air sampling device that mirrors the human respiratory system

the Anderson sampler

57

how long can airborne microbes stay in the air

hours

58

What type of handwash seems to be the best and killing microbes

chlorhexidine

59

What are HAI's

Hospital acquired infections

60

what is the best disinfectant for countertops

70-80% ethanol

61

What is the best disinfectant for large areas (floors)

substituted phenols or quats

62

what is the best disinfectant for semicritical instruments

steriplex SD

63

what is the best disinfectant for sterilization of heat-labile instruments

H2O2 Gas plasma

64

What does HEPA filter stand for

High
Efficiency
Particulate
Air
Filter