Download Infection Control Terms

Cycle of Infection
HST I
Objectives / Rationale
•Infection Control is an
increasingly important aspect
of health care for the client
and the health care
professional.
• Upon completion of this lesson, the
student will be able to:
• Identify the cycle of the infectious
process;
• Investigate ways to protect
themselves and patients from
infection; and
• Research common human
pathogens.
Infections and diseases are classified as:
Endogenous – it originates within.
Includes: metabolic disorders,
congenital abnormalities, tumors,
infections from microorganism
within the body.
Exogenous – originates outside the
body; includes invading
pathogens, radiation, chemical
agents, trauma, electric shock,
temperature extremes.
• Nosocomial – is one that is
acquired in a health care facility,
which is transmitted by health
care workers to the patient.
• Opportunistic – those that occur
when the body’s defenses are
weak; i.e. weakened immune
system.
Infections are also:
• Aerobic – the organism requires
oxygen to live.
• Anaerobic – the organism lives
and reproduces in the absences
of oxygen.
Infection Cycle:
• Infective Agent – pathogens
include bacteria, viruses,
funguses, rickettsiae, protozoa.
• Reservoir – where causative agent
can live. Includes the human
body, animals, environment, and
fomites or objects contaminated
with infectious material that
contains the pathogens.
• Portal of exit – way for causative
agent to escape from the
reservoir.
• Pathogens can leave the body
through urine, feces, saliva, blood,
tears, mucous discharge, sexual
secretions, draining wounds.
• Means of transmission – how it is
transmitted to another host.
• By: Direct Contact – person to
person, physical contact, or
contact with body secretions
containing the pathogen.
• Indirect Contact – from
contaminated sources such as
food, air, soil, equipment, etc.
• Indirect contact can include
touching contaminated
equipment or surfaces, breathing
in droplets carrying airborne
pathogens, or receiving the bite of
an insect carrying the pathogen.
• Portal of entry – way to enter a
new reservoir or host.
• Breaks in the skin or mucous
membrane; respiratory tract;
digestive tract; genitourinary tract;
circulatory system.
• Susceptible host – individual who
can contract the disease, unless:
• Defense mechanisms are intact.
• Immune system is functioning.
The cycle of infection can be broken:
• The infectious agent can be
neutralized or destroyed by
treatment.
• The reservoir host must maintain
personal hygiene.
• The portal of exit is closed by the
use of proper attire (gowns,
gloves, etc), control of body
secretions, proper handwashing.
• The route of transmission is
minimized through proper
handwashing, disinfection,
sterilization, and proper disposal of
contaminated materials.
• The portal of entry is blocked by
asepsis, disinfection, and
sterilization procedures.
• Health and wellness of the
individual is maintained.
Microorganisms and Disease
• Microorganism – an organism that
is too small to be seen by the
human eye.
• Fungi – simple plants such as
molds and yeasts
• Protozoa – only group classified as
an animal.
• Virus – cannot be seen by ordinary
microscope; not destroyed by
antibiotics.
• Bacteria – classification is
determined by the shape of the
bacteria and whether it grows with
or without oxygen. Only a few,
such as staphylococcus and
streptococcus cause disease.
• Cocci – round; includes
staphylococci which is in clusters
like grapes; causes boils, impetigo
and osteomyelitis.
• Cocci also includes streptococci,
round bacteria arranged in
chains; causes rheumatic fever,
streptococcal pneumonia, and
scarlet fever.
• Cocci also includes diplococci,
arranged in pairs – causes
gonorrhea and meningitis.
• Bacilla (i) – rod-shaped bacteria.
• Spirilla – bacteria shaped like
spirals.
• Rickettsiae – smaller than
bacteria; barely visible under
microscope. Causes typhus,
Rocky Mountain Spotted Fever.
• Pathogen – the term for a diseasecausing microorganism.
Vocabulary terms:
• Sterile means “free from all
organisms”, including spores and
viruses.
• Contaminated – organisms and
pathogens are present.
Asepsis – the absence of infection
• Medical Asepsis – practices and
techniques designed to protect
individuals from the spread of
disease.
• Antiseptic – substances that inhibit
the growth of bacteria. Some can
be used on the skin.
• Disinfectant – cannot be used on
skin; includes chemicals and
boiling.
Sterile – absence of all microorganisms
• Surgical asepsis – the use of sterile
technique to handle equipment,
maintain sterile fields, change
dressings, and dispose of
contaminated materials without
introducing harmful
microorganisms.
Sterilizing with an Autoclave
• The autoclave is the safest, most
efficient sterilization method.
• An autoclave is a piece of
equipment that uses steam under
pressure or gas to sterilize
equipment and supplies.
• It will destroy ALL microorganisms,
both pathogenic and nonpathogenic, including spores and
viruses.
Using an autoclave • Items that are to remain sterile
must be wrapped before they are
Items are cleaned and prepared
before being put in autoclave.
• autoclaved.
• Autoclave indicators are used to
insure sterility of the item.
Using chemicals for ‘disinfection’ • Since many chemicals do not kill
spores and viruses, chemicals are
not a method of sterilization.
• Chemicals are used to disinfect
instruments that do not penetrate
body tissue.
• Examples: 90% isopropyl alcohol,
formaldehyde-alcohol; 10%
bleach; Lysol, Cidex.
Epidemiology
• Tracing the occurrence of health
related events in society.
• Epidemiologist – a person who
specializes in the study of
outbreaks of diseases within a
population group.
• Endemic – the ongoing presence
of a disease within a population,
group or area. Example: the
common cold.
• Epidemic – a sudden and
widespread outbreak of a disease
within a population, group or area.
Example: a widespread outbreak
of measles or influenza.
• Pandemic - an outbreak of a
disease occurring over a large
geographic area, possibly
worldwide. Ex: AIDS, H1N1 flu.