Infection Prevention Flashcards
In a dental setting what serves as a reservoir for pathogens
air water and fomites
Healthcare associated infection (HAI)
refers to an infection acquired during the delivery of healthcare in any setting
microorganisms in the mouth and respiratory tract can be transported in ___
aerosols, slash/spatter, during dental procedures
Chain of infection (3 elements)
- a source or reservoir (contaminated air water or fomites
- susceptible host (portal of entry receptive to the agent/exposure to an adequate number of sufficiently
virulent microorganisms) - Mod of transportation (agent from the source to the host)
Infection control strategies intend to do what?
break one or more of the links -> preventing disease transmission
Pathogens associated with healthcare are derived from?
primarily human sources BUT contaminated objects and environmental sources are also implicated
Who can pass on pathogens
someone with an acute infection, in the incubation (subclinical) phase, or is asymptomatic
Factors that affect someone’s susceptibility
age
physical conditions
medications
underlying medical conditions
immunizations
consequences of being a susceptible host
- infected but remain asymptomatic
- colonization to symptomatic disease either immediately or after a period of asymptomatic latency
Aerosols
a liquid or solid particle less than 50 micrometers in diameter
stay airborne for an extended period before settling on environmental surfaces or enter respiratory tract through inhalation
droplets and droplet nuclei
0.5 - 1.0 micrometers in diameter have potential to enter lungs and settle within the pulmonary alveoli (HIGH RISK of infection transmission in the dental office)
Splash and Splatter
a mixture of air, water, and/or solid substances larger than 50 micrometers in diameter and are visible to the naked eye (ex. Blood; sneezes)
only airborne briefly - limited penetration to the respiratory system
droplets
airborne particles of moisture > 5 unit microns
limited to 3 feet of the source
droplet nuclei
residuals of droplets ranging from 1-5 unit microns that dry out while suspended in air.
droplet nuclei may remain in the air indefinitely and travel beyond 3ft from source.
Human hair is how big?
60-120 microns wide
percentage of nuclei in the dental office is less than 5 microns in size
95%
what size of microns can reach the epiglottis area of the throat?
5-10 micron
what size can reach deep down into the bronchi?
<5 microns
high speed handpieces ; ultrasonic scalers ; air/water syringes =
aerosols
dental plaque is major source of microorganisms, containing how many pathogens?
more than 700 known pathogens
how are pathogens transferred
direct or indirect contact
direct contact
transmission occurs when pathogens are transferred between individuals WITHOUT a contaminated intermediate
what could be a contaminated intermediate?
person
object
environmental surface
Indirect contact
transmission occurs when pathogens are transferred between individuals VIA a contaminated intermediate person object or surface
Respiratory Transmission
ALSO CALLED airborne transmission
may result from inhalation of droplets from inhalation of droplet nuclei
Direct Transmission happens through
broken skin
mucosal contact
Indirect transmission happens through
contaminated instruments
surfaces
Droplet transmission through
sneezing
coughing
Virulence is
ability to cause infection and damage
easily colonizes
grows rapidly
produces harmful substances
evades / counters body’s defenses
2 types of resistance
Innate
Acquired
Innate resistance is
physical (skin, mucous membranes)
Mechanical (secretions, cilia)
Chemical (stomach acid)
Acquired resistance is
cell-mediated (antibodies)
Immunity is
a condition of being able to resist a particular disease especially through preventing development of a pathogenic microorganism
Requirements for infection
Susceptible host
pathogen (sufficient numbers)
Portal of entry
mode of transportation
stages of infection
incubation
prodromal
acute or period of illness
convalescent or decline
incubation
the time between exposure and sings and symptoms
prodromal
the period between the appearance of initial symptoms and the full development
early signs and symptoms - not yet clinically specific or severe
acute or period of illness
the signs and symptoms of the disease are most obvious specific and severe
convalescent or decline
of pathogens begin to decrease
signs and symptoms decline
patients may become susceptible to developing secondary infections because their immune systems have been weakened
Causes of disease emergence
microbial changes
breakdown in public health measures
ecological changes
changes in human demographics behaviors
international travel and commerce
sanitization
process of physical cleaning to reduce the quantity of microbes and bioburden
process of sanitization
use of disinfectant and paper towel on surfaces
use of soap and brush on instruments
ultrasonic on instruments
*ALL should be done BEFORE sterilization or disinfection
Sterilization
Destruction of ALL microbial forms (including spores)
term intends absolutely destruction but probability of pathogenic or other organisms can never be reduced to zero
kinds of sterilization
heat (most common - used at SOD)
filtration
radiation
chemical
In oral healthcare settings the primary sterilizing methods are
steam under pressure
dry heat
what are used to sterilize heat sensitive instruments
germicides like chemical sterilant and high/intermediate/low level disinfectants
Antiseptics
a substance that stops or slows down the growth of microorganisms
used on living tissue
ex. skin / mucous membranes
Alcohol as an antiseptic
alcohol coagulates the protein in bacteria
30% solution with water penetrates bacteria and is more effective than 100%
Disinfection
less lethal than sterilization
doesn’t destroy spores and certain resistance microorganisms
applied to inanimate objects and environmental surfaces
(our target for cubical preparation)
Disinfectants are not used on what?
Skin
not used for tissue antisepsis due to it being toxic to skin
Liquid chemical disinfectant requirements
surface must be cleared of debris first
adequate contact time
correct temperature
correct pH
correct concentration
High level disinfectant
kills ALL pathogens but not all bacterial spores
extended contact (3-10 hours)
use on environmental surfaces is inappropriate
AKA chemical sterilant
High level disinfectant is used for
heat sensitive critical and semi critical items
*Not used in dentistry
Intermediate level disinfectant
destroys Mycobacterium TB ; most fungi ; most viruses ; vegetative bacteria
does NOT kill bacterial spores
labeled as tuberculocidal disinfectants
What doe we use to disinfect dental operative surfaces at UMKC
intermediate level disinfectant (cavicide)
surface disinfectant categories (2)
dual quaternaries
alcohol
dual quaternaries
surface disinfectant
most types in this category
use at UMKC
Alcohol
surface disinfectant
Unacceptable for instruments and surfaces
evaporates rapidly
does NOT kill spores
does not work in presence of blood and saliva
Low level disinfectant
kills most vegetative bacteria and some viruses and fungi
used for floors and walls in dental settings
what categorization system is used for sharps and instruments
spaulding’s classification system
*categories by potential risk of infection
According to spaulding patient care items can be categorized as
critical
semi critical
non critical
critical items
penetrate soft AND hard tissues
confer a high degree of risk for infection if contaminated with pathogens
EX. explorers ; scalpels ; burs ; scalers ; needles ; carpules
*must be sterilized
semi critical items
contact but do not penetrate (non sharp items that enter the oral cavity
EX. amalgam condensers ; mirrors ; reusable impression trays ; hand pieces ; suctions
*must be sterilized or for heat sensitive high level disinection
non critical items
items that do not enter the oral cavity but may be touched
come in contact with skin but not mucous membranes
EX. bracket table ; counter tops ; chair controls ; light handles ; computer keyboard ; tray ; door knobs
*require disinfectant or plastic barrier
What happened in response to the HIV epidemic in the mid 1980s
all blood and body fluids contaminated with blood were to be treated as infectious
in 1996 the CDC expanded universal precautions into what?
the concept of standard precautions
standard precautions
basically treat everyone as infectious
Controls to infection prevention (3)
administrative controls
engineering controls
work practice controls
Administrative controls are
policies procedures and enforcement measures targeted at reducing the risk of occupational exposure to infectious persons
Engineering controls are
devices that isolate or remove the risk of exposure to bloodborne pathogens in a workplace
EX. instrument cassettes ; sharps containers ; needle recapping devices
Work practice controls are
procedures that reduce the likelihood of exposure to infectious materials by altering the manner in which a task is performed
ex. replacing sharps container when full ; recapping a needle using the one handed scoop technique
OSHA: regulated waste
blood or other potentially infectious material in liquid or semi liquid state
items caked with dried blood that may release it
contaminated sharps
pathological / microbiologic waste with blood or other potentially infectious material
Regulated medical waste ; UMKC Red biohazard bag
solid waste soaked/saturated with blood or saliva
*dripping or squeezable dried on fluid that could flake off
contaminated sharp items
anesthetic carpules
surgically removed hard and soft tissue
Ultrasonic cleaners
use high frequency sound waves and cavitation to loosen and remove debris
16x more effective than scrubbing
less potential to injure self
*visible debris must be removed to not interfere with sterilization and disinfection process
Autoclave
steam under pressure
most dependable
most common
standard cycle 250 F ; 15 PSI ; 20min
dulls instruments
Flash Sterilizers
Steam
273 F ; 20 PSI ; 3-10 min
not intended for sole method of sterilization
Dry Heat
320 F ; 2 hr
338 ; 1 hr
long cycle
handpieces wont tolerate
poor penetration
doesn’t dull cutting edge
Chemiclave
Steam under pressure with chemical vapor
shorter cycle and less corrosive
chemical vapor is hazardous
Sterilization monitoring is done by
Spore testing weekly
spore test results should be maintained for at least 1 year
common reason to fail a spore test is
overloading the sterilizer
3 types of latex reactions
irritant contact dermatitis
allergic contact dermatitis
immediate allergic reaction (latex hypersensitivity)
what percentage of health care workers have some form of latex allergy
5-10%
Irritant Contact dermatitis
not an allergic skin reaction
least threatening type
due to repeated exposures
dry itchy burning irritated areas
allergic contact dermatitis
Type IV delayed reaction hypersensitivity may take 23-48 hours to develop from time of exposure
may result from allergy to chemicals used in glove manufacturing
more severe reaction can spread and lasts longer
latex allergy
type 1 (immediate) hypersensitivity to natural rubber latex proteins
reactions include nose, eyes, and skin reactions
more serious reactions include urticaria bronchospasm/respiratory distress
rarely shock or death
how to minimize contact dermatitis
dry hands completely before donning gloves
only use latex free gloves
only use gloves WITHOUT powder
