Infection Control Flashcards
Chain of infection
factors that lead to the transmission or spread of disease
reservoir
habitat in which the agent normally lives, grow, and multiplies.
Can be human, animal, or the environment
portal of exit
path by which a pathogen leaves its host.
Can exit through the placenta, cuts, needles in the skin, droplets from the respiratory tract, or saliva.
direct contact
microorganisms transferred from one infected person to another without a contaminated intermediate object/person or direct contact with soil harboring infectious organisms
EX: kissing :3
indirect contact
microorganisms are transferred from an infectious agent through contaminated object, person, suspended air particles, vehicles, or vectors.
EX: blood, saliva, and other secretions from patients
portal of entry
the way a pathogen gets inside the new host.
many portals of entry are the same as the portal of exit.
susceptible host
new home for the pathogen.
individuals can respond differently to the same pathogen due to factors such as genetics or immunity.
How to break the chain of infection?
if 1 of the 5 components is broken then the infection is stopped.
ex: using gloves when working in the mouth.
What is the most important procedure for preventing the spread of infection?
Hand washing!
Is the reservoir always the source from which an agent is transferred to a host?
no, for example, the reservoir for Clostridium botulinum is soil, but the source of most botulism infections in improperly canned foods.
How is Hepatitis A transmitted?
through the “fecal-oral” route.
Can bloodborne agents be transmitted by body fluids and sweat?
They can be transmitted by blood or body fluids EXCEPT sweat.
What are outbreaks of legionnaires?
they are traced to environmental reservoirs such as water supplies in cooling towers and evaporative condensers.
what infections are spread by direct contact?
infectious mononucleosis (mono), gonorrhea, hookworm via soil, herpes simplex virus, HIV, hepatitis
what infections are spread by indirect contact?
hepatitis B and C
what is droplet infection
relatively large (bigger than 10 microns), short-range aerosols produced by sneezing, coughing, or even talking. Can be spread through surfaces by touch and is considered direct transmission.
what are the types of droplet infections that can be spread?
influenza, mumps, rubella viruses, herpes viruses, coronaviruses.
Airborne infections
small particles called drop nuclei or aerosol particles are smaller than 10 microns and can be airborne for HOURS.
Examples of airborne infections
tuberculosis, chickenpox, measles, SARS-Cov-2.
Vehicles
food, water, biological products (blood), and fomites such as handkerchiefs, bedding, or scalpels that can carry infectious agents.
vectors
mosquitos, fleas, and ticks may carry infectious agents.
Blood-borne transmission
spread through blood and other body fluids (not including sweat)
most common blood-borne pathogens that healthcare workers are at risk for
HIV, hepatitis B, Hep C
What is a percutaneous injury?
healthcare worker who is injured by a contaminated syringe.
What is a mucocutaneous injury
a healthcare worker being splashed in the eye with blood
Standard precaution
precaution designed to protect the healthcare provider against blood-borne pathogens, from blood, bodily fluids, and excretions(except sweat).
What are diseases when standard precaution is used
HBV, AIDS/HIV
Sequence for donning PPE
gown, mask, glasses, handwashing, gloves.
(doff in opposite order)
N95 efficacy
filters out 95% of airborne particles including large and small.
What should be the alcohol concentration of hand sanitizers?
60-95% are most effective and can be used when no visible soil is seen on the hands.
What is transient flora?
colonizers of the superficial layers of the skin and can be removed with hand washing. They are acquired by contact with patients and contaminated surfaces.
What is resident flora?
flora attached to the deeper layers of the skin and is more resistant to hand washing.
What can be disposed of in the regular trash
patient bibs, barrier, PPE, and items NOT saturated with blood or saliva
Can blood-borne diseases be transmitted by contact with raw or treated sewage?
no, so the disposal of limited quantities of blood/other body fluids can be disposed in the sanitary sewer is safe :)
Can extracted teeth be returned to the patient
yes :p otherwise they need to be disposed in the medical waste containers
How to dispose of amalgam
DO NOT flush it down the sink or toilet
Recycle amalgam waste separately according to local regulation
sterilization
destruction of ALL microorganisms including spores by physical or chemical means
disinfectant
destruction of PATHOGENIC and other kinds of microorganisms by physical or chemical means.
May not destroy bacterial endospores
qualities of an ideal disinfectant:
broad-spectrum, fast-acting, non-toxic, compatible with materials, odor-free, and easy to use
Antiseptic
the substance that stops or slows down the growth of microorganisms
ex: alcohols, chlorohexidine, triclosan
High level disinfectant
FDA regulated disinfectant. Inactivates bacteria, mycobacteria, fungi, and viruses, not NOT bacterial SPORES.
Kills M. tuberculosis
Takes long contact time to inactive microbes so not suitable for environmental surfaces
low level disinfectant
does not kill M. tuberculosis
critical item
item at high risk for infection
AKA curettes, needles, surgical burs because they can penetrate soft tissue, bone or contact the bloodstream
REQUIRES heat sterilization
Semi-critical item
item at lower risk for infection
contact mucous membranes, non-intact skin, but will NOT penetrate soft tissues.
EX: radiographic film holders, mirrors, reusable trays.
Requires high-level disinfection or heat sterilization
non critical items
contacts intact skin but not mucous membranes
EX: BP cuff, xray tube head.
requires intermediate or low level disinfectant
clinical surface
does not touch the patient directly and has limited risk of disease transmission
EX: light handles, switches, pen, handles, counter tops.
cleaned with low/intermediate level disinfectant after each patient
housekeeping surface
does not touch the patient directly and has limited risk of disease transmission
EX: sink or floor
can be decontaminated with detergent and water only.
Surfactant
loosens, emulsifies, and holds organism in suspension, so they can be rinsed away easier
Cavitation process
bubbles formed by the process collapse on the surface and disturb the organisms
automatic washer
cleans and thermally disinfects instruments by using a high-temperature cycle rather than a chemical bath.
how do sterilizers work
destroys microorganisms by creating irreversible coagulation, denaturation of enzymes and proteins, and oxidization of cells.
Steam (moist) autoclave
pressure chamber that generates moist heat at temps of 121 celcius (250F) for 20-30 mins or 132 C (270F) for 3-10 mins
gravity displacement steam sterilizer
steam is admitted and unsaturated air is forced out of the chamber through a vent
High-speed pre-vacuum steam sterilizer
air is removed to create a vacuum, then high temperature pressured steam is introduced (allow faster steam penetration throughout, and temperature is higher than gravity displacement type)
Dry heat sterilization technique
uses higher temperatures of 162-180C (320-375F) for 6-20mins (rapid type) or 1-2 hours (oven type)
Unsaturated chemical vapor
involves heating a chemical solution of alcohol and formaldehyde in a closed pressurized chamber. Generates heat at temperatures of 135C (270F) and pressures of 20-40 lbs/in2 for 20-30 mins.
requires adequate ventilation to prevent toxic fume accumulation
flash cycle
instruments are sterilized unwrapped.
Only used in EMERGENCY situations
Cold sterilization
requires up to 10 hours of exposure to a liquid agent registered as sterilant/disinfectant. Instruments should be rinsed with water, dried, and placed in a sterile container
Ethyl oxide
ethylene oxide gas is used at temperatures of 25C (75F) for 10-16 hours.
Internal chemical monitors
used inside EACH package to ensure the sterilizing agent has penetrated the packaging material and has actually reached the instruments inside.
Class 1 external process indicator
autoclave indicator tape as a form of chemical monitoring that changes color when exposed to heat.
What is the most accepted method for monitoring the sterilization process?
biologic monitoring (live spore testing)
optimum flow for instrument processing
receiving, cleaning, decontamination, packaging, sterilization, and storage areas.
After an exposure incident, should the area be squeezed to express fluid to reduce the risk of infection with blood borne pathogens?
no, the area should be washed with antimicrobial soap and water. There is no evidence to support that squeezing reduces risk
Does the use of a cassette increase sterilization’s effectiveness?
no
Material Safety Data Sheets (MSDS) includes
-information for safe handling, clean up, and disposal of the chemical
-physical and chemical description
-contact info of supplier
-date
-list of any health, environment, flammability, or reactivity risks
rickettsia
type of bacteria commonly transmitted through bites, such as ticks, fleas, and lice.
