Lecture | Infection control Flashcards
destruction of all forms of life, including bacterial SPORES– all-or-nothing process.
Sterilization
selectively eliminating only a predefined scope microorganisms
Disinfection
is due to the biochemical composition of microorganisms and various mechanisms that they can use to protect themselves.
viability
enumerate types of bacteria from most resistant to least resistant
prions, bacterial spores, mycobacteria, non-lipid viruses, fungi, bacteria, and lipid viruses
An organism that is most resistant to the actions of heat, chemicals, and radiation
Prions
naked pieces of protein, similar to a virus but without the nucleic acid.
Prions
agents that cause a number of degenerative diseases of the nervous system
Prions
transmissible spongiform encephalopathy—mad cow disease, Creutzfeldt Jakob disease are caused by
Prions
Referred to as the microbial load (bioburden)
Number of Organisms
determines the exposure time that is necessary for 99.9% elimination of the microorganisms
microbial load/bioburden
Ethanol is a volatile chemical so if its in its absolute form it will
evaporate
not preferred as an disinfecting agent
ethanol
affects killing activity by inactivating the disinfecting agent.
Organic material; blood, mucus, and pus
easily inactivated by organic material
Bleach (sodium hypochlorite)
endoscopic instruments are readily damaged by the heat generated in an autoclave. The alternative method is
chemical method
contact time of surface disinfection and Instrument soak
Surface disinfection - 1 minute
Instrument soak- 20 minutes
temperature of Disinfectants
20°C to 22°C
pH of Glutaraldehyde
> 7.0
pH of Quaternary Ammonium Compounds
9.0-10.0
layers of microorganisms that often have a protective material over them that shields them from outside environmental factors
biofilm
disinfection level of sporicidal
High
disinfection level of Tuberculocidal
intermediate
device classification:
materials that invade sterile tissues or enter the vascular system. These materials are most likely to produce infection if contaminated and require sterilization
Critical materials
device classification:
come into contact with mucous membranes, they require high-level disinfection agents
Semicritical materials
device classification:
require intermediate-level to low-level disinfection before contact with intact skin
Noncritical materials
Most common; safest method and Burned to ashes
Incineration
Incineration temperature
870°C - 980°C
limits the use of incineration
toxic air emissions and the presence of heavy metals
Uses AUTOCLAVE
moist heat
Moist Heat for media, liquids, & instrument uses a temperature, psi, and exposure time of ?
121°C (250 °F) at 15psi for 15 minutes
moist heat temp and time for infectious medical waste
132°C for 30-60 minutes
Also called as steam under pressure
moist heat
used to sterilize bio hazardous trash and heat-stable objects
moist heat
a large pressure cooker
autoclave
Use to determine whether sterilization process is effective; serves as a quality control
biological indicator
moist heat biological indicator
Bacillus steatothermophilus
Tyndallization temp & exposure time
100°C for 30 min for 3 consecutiuve days
Alternates heating & incubation
Tyndallization
Inspissation temp. & exposure time
76-80°C for 2 hours for 3 consecutive days
Dry Heat temp & exposure time
160-180°C for 1.5 - 3 hours
Dry Heat Biologic indicator
Bacillus subtilis var. nigar
used to sterilize items such as glassware, oil, petrolatum, or powders.
Dry Heat
method of choice for antibiotic solutions, toxic chemicals, radioisotopes, vaccines, and carbohydrates or for heat sensitive
Filtration
filtration wherein Liquids: Pulling the solution through a
cellulose acetate or cellulose nitrate
air filtration
HEPA filters
(High Efficiency Particulate Air)
HEPA filters is for organisms size
> 0.3 um
used for sterilizing disposables such as plastic syringes, catheters, or gloves before use
Ionizing radiation
composed of short wavelength and high energy gamma rays
Ionizing radiation
used in gaseous form for sterilizing heat- sensitive objects
Ethylene oxide
Ethylene oxide Biological indicator:
Bacillus subtilis var. globigii
disadvantage of Ethylene oxide
explosive
450 to 700 mg/L of chamber space at 55°C to 60°C for 2 hours
Ethylene oxide
chemical disinfection For HEPA filters in BSC
Formaldehyde Vapor & Vapor Phase Hydrogen Peroxide
Glutaraldehyde is sporicidal in exposure time of
3 to 10 hours
chemical disinfection for medical equipment such as
bronchoscopes, because it does not corrode
lenses, metal, or rubber.
Glutaraldehyde
Remains active in the presence of organic
matter
Glutaraldehyde
use of glutaraldehyde or peracetic acid is
called
Cold sterilization
Chemicals use to destroy microbial life for shorter period or selective in its action
Disinfectants
Disinfectants that are used in living tissue (skin)
Antiseptics
kill Mycobacterium tuberculosis various fungi. they are not sporicidal and have poor activity against nonenveloped viruses
Alcohols
inactivated by the presence of organic material
Sodium hypochlorite, Alcohols, and Quaternary Ammonium Compounds
It is not recommended in any form be used as a disinfectant or sterilant on a routine basis.
Formaldehydes
Iodine can be used as a disinfectant in one of two forms
tincture or iodophor
tinctures are alcohol and iodine solutions, used mainly as
antiseptics.
tincture or iodophor are an example of
Halogens
dilution of disinfectant for Blood spills
1:10 dilution of a 5.25% concentration of sodium hypochlorite solution
Used as a disinfectant of water
Chlorine & Chlorine Compounds
usually use as an eyedrop solution
Silver nitrate
Silver nitrate is an example of
Heavy Metals
action is mediated through disruption of the cellular membrane, use as skin antiseptics and disinfectants
Detergents: Quaternary Ammonium Compounds
Denatures proteins; disrupt cell membrane
Phenolics
main use is in the disinfection of hospital, institutional, and household environments. They are also commonly found in germicidal soaps
Phenolics
Gaseous form use for sterilization of heat-sensitive objects
Ethylene oxide
Boiling at 100°C for 15 minutes kills
vegetative bacteria
Pasteurizing kills food pathogens without damaging the nutritional value or flavor at a temperature and exposure time of
63°C for 30 minutes or 72°C for 15 seconds
form of ultraviolet rays is of long wavelength and low energy
Nonionizing radiation
drug or chemical that inhibits reproduction of microorganisms, but does not kill necessarily kill them
Microbiostatic Agents
process that combines dehydration (drying) and freezing; Use for some isolates to preserve for further studies
Lyophilization
merely slows the growth of most microorganisms; it does not completely inhibit growth
Cold/refrigeration
sudden increase in the occurrence of a disease
Outbreak
This step ensures that the rest of the investigation is based on a single definition.
Case Definition
One needs to be certain that all the suspected cases match the case definition and that there is more than an expected number of cases.
Confirm that an outbreak exist
Additional suspected cases may be discovered by more detailed investigation or by the new occurrence of cases.
Find additional cases
gather as much information as possible about the cases with respect to person, place, and time
Characterize cases
may be constructed to assist in the visualization of the outbreak numbers over time
An epidemiologic curve
established as a best guess about the likely reservoir, source, and means of transmission. In testing that hypothesis, a control group is established; then the event is compared in the incident and control groups
Form a hypothesis
Test the hypothesis with control groups and data collected
Test the hypothesis
evaluate the effectiveness of the intervention
Institute control measures
Determine whether the implemented activities have an impact on the outbreak.
Evaluate
Document the investigation and communicate with all involved parties
Communicate the findings
plays a crucial role in providing investigative support in an outbreak investigation and in the creation of routine surveillance information
microbiology laboratory
patterns of sensitivity and resistance to antimicrobial agents in bacteria, can often be used in the investigation of an outbreak
Antiobiograms
analysis of molecules, such as proteins and nucleic acids, for the detection, identification, and characterization of microorganisms to generate isolate-specific markers to assess epidemiologic relatedness
Molecular Epidemiology
prevents full contact between objects and agent
organic materials; mucus, blood, pus
use of both of these disinfectant agent negate the activity of both disinfectant
sodium hyphochlorite and quaternary ammonium compound
