Glossary
Glossary
Antiseptic 102
A chemical agent used on the skin and on the mucous
membranes in order to remove or to kill microorganisms
without causing damage or irritation to the tissue. An
antiseptic may also prevent the growth and development of
microorganisms. Antiseptics are not meant to be used on
inanimate objects such as instruments and surfaces.
Antiseptic Hand
Wash
An antiseptic hand wash is one that will destroy or remove
resident as well as transient microorganisms from hands.
Aseptic techniques
Practices that help reduce the risk of post-procedure
infections in clients by reducing the likelihood that during
clinical procedures microorganisms will enter areas of the
body where they can cause disease. While all infection
control practices contribute to this effort, aseptic technique
refers to those practices performed just before or during a
clinical procedure. These include proper handwashing,
surgical hand scrubs, the use of barriers such as gloves
and surgical attire, proper preparation of a client for clinical
procedures, the maintenance of a sterile field, the use of
good surgical technique, and the maintenance of a safe
environment in the surgical/procedure area.
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Carriage
The presence in an individual (host) of a pathogenic
microorganism without clinical symptoms of infection or
sometimes without signs of any immune response.
Case 11
A person with symptoms.
Cellular Immunity
Certain types of white blood cells that coordinate and
memorize exposure to microorganisms foreign to the body.
It is a critical part of the body’s immunity. These cells have
the capacity to coordinate destruction of invading
pathogens by direct contact or by the activation of
substances (antibodies, interferon), which will inactivate
them. Cellular immunity is the component of the immune
system that memorizes antigens on microbes to activate a
protective response should there be subsequent exposure.
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Glossary
Chemical sterilization
See sterilization.
Chemoprophylaxis
The administration of antimicrobial agents in order to
prevent the development of an infection or to prevent the
progression of an infection into active manifest disease.
Cleaning
The first step in processing instruments and other items for
reuse. This process entails scrubbing instruments and
other items with a brush and using detergent and water
before they are sterilized or high-level disinfected. Cleaning
should remove blood and other body fluids, organic
material, tissue, and dirt. In addition, cleaning greatly
reduces the number of microorganisms (incl. bacterial
endospores) on instruments and on other items, making it
a crucial processing step. If instruments and items have not
first been cleaned, sterilization and high-level disinfection
(HLD) may not be effective because microorganisms
trapped in organic material may be protected and may
survive sterilization or HLD process and organic material
and dirt can make the chemicals used in chemical
sterilization and HLD less effective.
Cohort
A group of patients infected or colonized with the same
microorganisms that are grouped together in a designated
area of a unit or ward.
Colonization
Reproduction of microorganisms in the spaces or on the
surfaces of the host’s body without any tissue damage or
clinical symptoms of infection.
Commensal
A microorganism resident in or on a body without causing
clinical infection.
Communicable
Period
The time in the natural history of an infection during which
transmission may take place.
Conditional
Pathogens
Pathogens which cause disease other than trivial local
infections only in persons with reduced resistance to
infection (incl. newborn infants) or when implanted directly
into tissue or in a normally sterile body area.
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Glossary
Contact
An exposed individual who might have been infected
through transmission from another host or from the
environment.
Contamination
Entrance of infectious, organic, or chemical agents into
tissues and spaces that are normally sterile (clean) or that
have other permanent inhabitants.
Conventional
Pathogens
Cause disease in healthy individuals in the absence of
specific immunity.
Disinfectant
A chemical agent used to kill microorganisms on inanimate
objects, such as instruments and surfaces. Disinfectants
are not meant to be used on skin or on mucous
membranes.
Dry-heat sterilization
See sterilization.
(electric oven)
Endemic
The usual level or presence of an agent or disease in a
defined population during a given period of time.
Endogenous
infection
The causative agent of the infection is present in the
patient at the time of admission to the hospital as part of
his/her normal flora but there are no signs of infection. The
infection develops during the stay in hospital as a result of
the patient’s altered resistance or of surgery.
Environmental
cleaning or
“housekeeping”
The general cleaning and maintenance of cleanliness in a
health care facility. In addition to cleanliness, the purpose
of housekeeping is to reduce the number of
microorganisms in the facility (thus reducing risk of
infections to patients and staff members) and to provide an
appealing work and service-delivery space.
Epidemic
An unusual higher than expected level of infection or
disease by a common agent in a defined population in a
given period.
Epidemic incidence
rate
Incidence rate that exceeds an ordinary level or the level
that is anticipated within the specific population during a
certain period of time.
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Glossary
Epidemiological
surveillance
A system for collecting, analyzing, and interpreting data on
infectious diseases (nosocomial infections) including
periodic reporting.
Epidemiology
The study of the occurrence and cause of disease in
populations.
Exogenous infection
Infection occurs from an outside source (infection by
colonization following cross-infection). During the stay in
the hospital the patient comes into contact with new
infective agents either from contact with hands of staff or
from poorly sterilized equipment and may become
colonized and subsequently may develop an infection.
Flora
Microorganisms resident in an environmental or body site.
General waste (= non- Non-hazardous waste that poses no risk of injury or
hazardous waste)
infections. Similar in nature to household trash, general
waste includes uncontaminated paper, boxes, packaging
materials, bottles, plastic containers, and food-related
trash.
See also medical or hazardous waste.
Hemodialysis
Hemodialysis removes toxins, electrolytes, and fluid by
circulating the patients’ blood through a hemodialyzer
(artificial kidney). Patients are usually scheduled to receive
hemodialysis for two to six hours three times per week.
High-level
disinfection (HLD)
This step in processing instruments and other items for
reuse is capable of killing bacterial spores when used in
sufficient concentration and time or, for a physical process,
sufficient temperature under suitable conditions. It is
therefore expected to be effective against vegetative
bacteria,
fungi,
viruses,
parasites
and
other
microorganisms. It does not kill high numbers of bacterial
spores. HLD is suitable for instruments and other items that
will come in contact with broken skin or intact mucous
membranes. HLD can be performed by boiling, by the use
of chemicals, or by steaming.
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Glossary
Humoral Immunity
These are antibodies or proteins produced by certain cells
in the body which attack pathogens that enter the body and
try to stop them from spreading or from attaching
themselves to specific cells or sites.
Immunity
The resistance of a host to a specific infectious agent.
Immunocompromised A state of reduced resistance to infection that results form
a malignant disease, drugs, radiation illness or congenital
defect.
Incidence
The number of new cases of a disease (or event) occurring
in a specified time.
Incidence rate
The ratio of the number of new infections or diseases in a
defined population in a given period to the number of
individuals at risk in the population.
Incubation period
The time between contact with a pathogenic agent and
appearance of the first clinical symptoms of disease.
Index Case
The first case to be recognized in a series of transmissions
of an agent in a host population.
Infection
The process of interaction between a macroorganism and
a microorganism in which the latter enters the host’s body,
reproduces, and may affect tissues directly (invasion)
through processes that can include toxin secretion or
indirectly as a result of immune reactions.
Infection control
A system of measures based on epidemiological diagnosis
directed at preventing development and spread of
infectious diseases in a health care facility.
Infection reservoir
A long-term infection source that supports the existence of
a parasitic species in nature.
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Glossary
Instruments and
other items
As used in the guidelines, this term includes:
Instruments used during surgery or other clinical
procedures such as pelvic examination, insertion of IUD,
childbirth, dental examinations, etc.
Other items that are reused during the delivery of health
services, such as pickups (lifters or cheatle forceps),
instrument pans and trays, linen, etc.
Intrinsic
contamination
Contamination before use. This is usually due to
contamination or faulty sterilization of fluids during
manufacture.
Isolation
The physical separation of an infected or colonized host
from the remainder of the at risk population in an attempt to
prevent transmission of the specific agent to other
individuals and to patients.
Medical waste
Medical waste consists of several different subcategories
of waste generated in the diagnosis, treatment, and/or
immunization of clients, including:
(= hazardous waste)
Infectious waste: Potentially infectious waste includes
all waste items that are contaminated with or
suspected of being contaminated with body fluids.
Examples include: Blood and blood products and other
body fluids, as well as waste from dialysis and
dentistry units, wastes from isolation units, wound
dressings, etc.
Anatomic waste: Anatomic wastes consist of recognizable
body parts and tissues (e.g., placenta), extracted tumors,
waste from microbiology labs, and animal carcasses.
Sharps waste: Sharps waste consists of used syringes,
needles, disposable scalpels and blades, etc.
Chemical waste: Waste containing chemical substances
e.g., laboratory chemicals, empty bottles of lab or
pharmacy chemicals, disinfectants that have expired or are
no longer needed, etc.
Pharmaceutical waste: Waste containing pharmaceutical
substances. Examples include: Expired, unused, and
contaminated pharmaceuticals, e.g., expired drugs,
vaccines and sera.
Genotoxic waste: Genotoxic waste consists of highly
187
Glossary
hazardous, mutagenic, teratogenic, or carcinogenic waste
containing substances with genotoxic properties. Examples
include: Cytotoxic and neoplastic drugs (used in cancer
treatment) and their metabolites and genotoxic chemicals.
Radioactive materials: Examples include: Unused liquids
from radiotherapy or laboratory research; contaminated
glassware, packages, or absorbent paper; urine and
excreta from patients treated or tested with unsealed
radionucleotides, etc.
Heavy metals: Heavy metal waste consists of both
materials and equipment with metals and derivatives.
Examples
include:
Batteries,
broken
mercury
thermometers, manometers.
Microbial flora of the
skin
The microbial flora of the skin can be divided into two
categories:
Resident microorganisms (“colonizing flora”) include
Staphylococcus
species
and
diptheroids.
These
microorganisms are considered permanent residents of the
skin and are not readily removed by mechanical friction.
Resident microorganisms in the deep layers may not be
removed by handwashing with plain soaps and detergents,
but they can usually be killed or inhibited by handwashing
with products that contain antimicrobial ingredients.
Transient non-colonizing flora include microorganisms that
come into contact with skin through interactions with
patients, with equipment, or with the environment. Noncolonizing flora are not consistently present in the majority
of persons and survive only a limited period of time. These
organisms are primarily gram-negative bacilli and are often
acquired through activities that involve close contact with a
patient’s secretions or excreta. Non-colonizing flora are
easily removed by simple, efficient handwashing.
Microbiological
Clearance
The reduction of the number of pathogenic microorganisms
in a specimen below that detectable by conventional
means.
Microorganisms
Organisms that can be seen only with the magnification of
a microscope. They exist everywhere in the environment in people, animals, plants, soil, air, and water and other
solutions.
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Glossary
Minimal infective
dose of a
microorganism
For every type of microorganism, the minimal infective
dose can be determined. This is the lowest number of
bacteria, viruses, or fungi that cause the first clinical signs
of infection in a healthy individual.
Nosocomial
infections (NI)
=Health care
associated HAI
Nosocomial infections – known also as health care
associated infections, hospital-associated infections, and
hospital infections – are infections that are not present in
the patient at the time of admission to the hospital but
develop during the course of the stay in the health care
facility. Hospital-acquired infections can appear after
discharge. Infections developed by personnel as a result of
working in a hospital are also considered to be nosocomial
infections.
Occupational
exposures
The Occupational Safety and Health Administration
(OSHA) in the United States defines occupational exposure
as any “reasonably anticipated skin, eye, mucous
membrane, or parenteral contact with blood or other
potentially infectious material(s) that may result from the
performance of an employee’s duties”.
Opportunistic
Pathogens
Cause generalized disease only in patients with profoundly
diminished resistance to infection.
Outbreak
Two or more epidemiologically cases of infection linked in
place and/or time that are caused by the same
microorganism.
Pathogen
A microorganism capable of producing disease.
Pathogenicity
The ability of a microorganism to cause disease.
Peritoneal Dialysis
Peritoneal dialysis removes toxins, electrolytes, and fluid
by diffusion through the peritoneal membrane. Peritoneal
dialysis requires placement of a catheter into the abdomen
for access and repeated infusion and drainage of dialysate.
Prevalence Rate
The ratio of the total number of individuals who have a
disease at a particular time to the population at risk of
having the disease.
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Glossary
Protective Isolation
or Environment
This type of isolation should be used for severely
immunocompromised patients who are highly susceptible
to and need protection from infection from both persons
and the environment and are not required in most facilities
unless there is a program for bone marrow transplantation.
See CDC Guidelines for HSCT .
Reservoir
Any animate or inanimate focus in the environment in
which an infectious agent may survive and multiply and
which may act as a potential source of infection.
Routine Hand Wash
Routine handwashing is the removal of dirt, organic
material, and transient microorganisms.
Scoop Technique
One hand –recapping. This method is only recommended if
it is necessary, as recapping needles is dangerous.
Seroconversion
The development of antibodies not previously present in a
host resulting from a primary infection.
Sharps-disposal
container
A puncture-resistant container for disposal of used needles
and syringes and other sharp objects, e.g., blades.
Source Isolation
The aim of this isolation is to prevent the transfer of
microorganisms from infected patients who may act as a
source of infection to staff or to other patients. For certain
airborne transmissible infectious diseases the room should
be at negative pressure with respect to the corridor.
Source of
nosocomial
infections
The place in which a microorganism accumulates and from
which a microorganism is directly transmitted to a
susceptible host.
Sporadic case
A single case which has not been associated with other
cases, excreters, or carriers in the same period of time.
Standard Precautions
A set of clinical practice recommendations to help minimize
the risk of exposure to infectious materials, such as blood
and other body fluids, by both clients and staff. Standard
precautions help break the disease-transmission cycle at
the mode of transmission step.
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Glossary
Steam sterilization
(autoclaving)
See Sterilization.
Sterile
Free from all living microorganisms.
Sterile Service
Department (SSD)
The sterile services department (SSD) is vital for an
effective Infection Control program. Using its expertise and
knowledge of sterilization and of disinfection to ensure high
standards of cleanliness, an SSD always results in longterm savings.
Sterilization
The sterilization process eliminates all microorganisms
(bacteria, viruses, fungi, and parasites), including bacterial
endospores. Sterilization is recommended for instruments
and for other items that will come in contact with the
bloodstream or tissues under the skin. The three methods
of sterilization are:
Steam sterilization (autoclaving): This method requires
moist heat under pressure. For steam to be produced,
there must be sources of both water and heat. A heat
source is necessary to maintain the required temperature
and pressure.
Dry heat sterilization (electric oven): This method requires
heat for a specific period of time. For dry-heat sterilization
to be achieved, a constant supply of electricity is
necessary. Only glass or metal objects can be sterilized by
this method, because high temperatures are necessary for
sterilization to be achieved.
Chemical sterilization: This method is used for instruments
and other items that are heat-sensitive or when heat
sterilization is unavailable. Instruments and other items can
be sterilized by soaking them in a chemical solution, such
as a product containing glutaraldehyde, followed by rinsing
them in sterile water.
Surgical attire
Attire such as gloves, caps, masks, and gowns that help
reduce the risk of post-procedure infections in clients by
reducing the likelihood that clients will be exposed to
potentially infectious microorganisms. In addition, this attire
– as well as protective eyewear, waterproof aprons, and
sturdy footwear – protects the service provider from
exposure to clients’ potentially infectious blood and other
body fluids.
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Glossary
Surgical Scrub
A surgical hand scrub is performed to remove transient
flora and to reduce resident flora for the duration of surgery
in case of glove tears.
Susceptible
A person presumably not possessing sufficient resistance
(or immunity) against a pathogenic agent who contracts
infection when exposed to the agent.
Transmission
mechanism
The evolutionary formed ability of a pathogen to move from
one host individual to another. Under hospital conditions it
is realized only when the causative agents of traditional
infections are imported.
Transmission route
The aggregate of transmission vectors operative under
specific conditions in a given infection.
Virulence
Degree of pathogenicity (potential of a given
microorganism to cause disease in a definite host). The
concept includes infectivity, invasiveness, and toxicity.
Zoonosis
An infectious disease
animals to humans.
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transmissible
from
vertebrate