direct contact
microorganisms are spread from blood and blood-containing body fluids directly through the mucous membrane or non-intact skin (from cuts or abrasions)
indirect contact
microorganisms are spread from an infectious agent through a contaminated intermediate (object, person, suspended air particles, vehicles, or vectors)
vehicles
food, water, biologic products (blood) and fomites (inanimate objects) that can carry an infectious agent
vectors
mosquitoes, flees, and ticks that can carry an infectious agent
the most common blood-borne diseases
HIV, hepatitis C, and hepatitis B
chain of infection
reservoir
portal of exit
mode of transmission
portal of entry
susceptible host
reservoir
habitat in which the agent normally lives, grows, and multiplies
can be a human, animal, or the environment
portal of exit
path by which a pathogen leaves its host (previous home)
mode of transmission
method of transportation the pathogen uses to arrive at the new home (direct or indirect contact)
portal of entry
the entrance the pathogen uses to get inside the new home (new host)
often the portal of entry is the same as the portal of exit
susceptible host
new "home" for the pathogen
standard precaution
designed to protect the healthcare professional against blood, bodily fluids, non-intact skin, mucous membranes, saliva
expanded new term for Universal Precaution
is the proper way to treat healthy and diseased patients
universal precaution
is based on the concept that all blood and bodily fluids that might be contaminated with blood should be treated as infectious because patients with blood-borne infections can be asymptomatic or unaware that they are infected
sequence for donning PPE
clothing > mask > eyewear > handwashing > gloves
what is the most important measure for preventing the spread of pathogens?
handwashing
transient flora
colonizes on superficial layers of the skin and can be removed by hand washing
the organisms are acquired by patient contact can contaminated surfaces and therefore are associated with heath-care associated infections
resident flors
attaches to deeper layers of the skin and is more resistant to removal
the organisms are less likely to be associated with infections
what is the major cause of disease transmission to health care personnel?
needle-stick injuries
flushing lines
20-30 seconds between patients
2 minutes at the beginning of the day (not required by CDC)
sterilization
destruction of all microorganisms including spores by physical or chemical means
disinfection
destruction of pathogenic and other kinds of microorganisms by physical or chemical means
less lethal than sterilization
disinfectant
germicide used on inanimate objects to destroy all recognized pathogenic microorganisms but not necessarily all bacterial endospores
Qualities of an ideal disinfectant
broad-spectrum
fast-acting
non-toxic
compatible with materials
odor free
easy to use
antiseptic
germicide used on skin or living tissue
high-level disinfectant
FDA-regulated disinfectant
inactivates bacteria, mycobacteria, fungi, and viruses, but not necessarily high number of bacterial spores
kills M. tuberculosis
used on medical devices but not
intermediate-level disinfectant
EPA-registered hospital disinfectant with tuberculocidal claim
inactivates bacteria, majority of fungi, and majority of viruses but not bacterial spores
kills m. tuberculosis
commonly used for environmental surfaces
low-level disinfectant
EPA-registered hospital disinfectant without tuberculocidal claim
inactivates the majority of bacteria, certain fungi, and certain viruses, but cannot be relied upon to inactivate resistant microorganisms
critical item
item at high risk for infection
penetrates soft tissue, bone, or contacts the bloodstream
requires heat sterilization
semi critical item
item at lower risk for infection
contacts mucous membranes, non-intact skin, but will not penetrate soft tissue
requires high level disinfection or heat sterilization
non critical item
contacts intact skin but not mucous membrane
requires immediate or low level disinfectant
clinical surface
does not touch patient directly and has limited risk of disease transmission
housekeeping surface
does not touch patient directly and has limited risk of disease transmission
surfactant
loosens, emulsifies, and holds organism in suspension, so as to be more readily rinsed away
ultrasonic cleaning
use for 1-15 for loose instruments
10-20 minutes for cassettes
sterilizers
destroys microorganisms by creating irreversible coagulation, denaturalization of enzymes and proteins, and oxidation of cells
steam autoclave
generates moist heat at temperatures of 121-135 C or 250-270 F and pressure of 15-20 lb/in^2
gravity displacement
steam is admitted and unsaturated air is forced out of the chamber through a vent
high-speed pre-vacuum
air is removed to create a vacuum, then high temperature pressured steam is introduced
dry heat
uses higher temperatures of 162-180 C or 320-375 F for 6-20 minutes (rapid type) or 1-2 hours (oven type)
useful for maintaining sharp edges of instruments and prevent corrosion
unsaturated chemical vapor
involves heating a chemical solution of alcohol and formaldehyde in a closed pressurized chamber
generates heats at temperatures of 135 C or 270 F and pressures of 20-40 lb/in^2 for 20-30 minutes
less corrosive
adequate ventilation necessary
flash cycle
instruments are sterilized unwrapped
used only in emergency situations
cold sterilization
requires up to 10 hours of exposure to a liquid agent registered as sterilant/disinfectant
should be rinsed with water, dried, and placed in a sterile container
ethyl oxide
ethylene oxide gas is used at temperatures of 25 C (75 F) for 10-16 hours
mostly used in hospital settings
tools should be aerated for 24 hours after sterilization
mechanical monitoring
assess the time, temperature, and pressure of a cycle
correct readings do not ensure sterilization, but incorrect readings can be an indication of a problem
chemical monitoring
heat-sensitive chemicals change color when exposed to certain temperatures (chemical indicator tape)
does not provide proof of sterilization; proof only that correct temperature was reached
biological monitoring
the most accepted method for monitoring the sterilization process
highly resistant spores (geobacillus or bacillus) are passed through the sterilizer and cultured to determine their inactivity
minimal weekly monitoring
what are common reasons for a positive spore test?
overloading: failure to provide adequate package separation and incorrect/excessive packaging material
exposure report should include
date and time of exposure
details of the procedure being performed
details of the exposure
details regarding whether the source material was known to contain a pathogen
details regarding the exposed person
details regarding counseling, post-exposure manag
CDC
federal public health agency that makes recommendations based on scientific research
focuses on infectious diseases and provides information regarding infection control
not a regulatory agency and does not test or evaluate products
NIOSH
National Institute for Occupational Safety and Health
federal institute the makes recommendations for the prevention of work-related disease and injury (part of the CDC)
conducts research on latex allergies
OSHA
Occupational Safety and Health Administration
regulatory agency charged with the enforcement of safety and health of employees
develops workplace standards to ensure safe working conditions in places of employment
EPA
Environmental Protection Agency
federal agency charged with protection of human health and the environment
regulates disinfectants/wastes
FDA
Food and Drug Administration
federal agency responsible for the safety, efficacy, and security of human or biological products, medical devices, nation's food supply, and products that emit radiation
OSAP
Organization for Safety and Asepsis Procedures
non-profit organization for dentistry that promotes infection control
HIPAA
Health Insurance Portability and Accountability Act
establishes national standards to protect individuals' medical records and other personal health information