Transcript TPJ 3C1 Principles of Infection

Principles of
Infection
What is an infection?
n
n
an infection results if pathogens
increase in number and alter the
functioning of normal tissues
Some infections can spread to other
people -- contagious
Principles of Infection
understanding the basic principles
of infection is essential for any
health care worker in any field of
health care.
1. Chain of Infection
2. Signs and Symptoms of Infection
3. Asepsis
Chain of Infection
in order for an infection to result, six
factors must be present
these factors occur in a cyclical pattern
if the chain is broken, infection will not
occur
Chain of Infection
Infectious Agent – pathogen such as a
bacteria or virus.
Reservoir – a place in which the
pathogen can grow and multiply eg.
humans, insects, food, water
– Fomites are inanimate objects
contaminated with infectious material that
contains pathogens
» Ex: doorknobs, bedpans, linens
Chain of Infection
Portal of Exit – way for the pathogen to
escape from the reservoir in which it has
been growing.
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–
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–
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Respiratory tract
Skin
Blood
Gastrointestinal tract
Mucous membranes
Chain of Infection
Mode of Transmission – way in which a
pathogen can be transmitted to another
reservoir.
– eg. the virus that causes chickenpox can
be transmitted by direct contact or
airborne droplet.
– Contaminated hands are one of the most
common modes of transmission.
» Hand washing is one of the most effective
means of preventing the spread of
pathogens.
Chain of Infection
Portal of Entry – way for the pathogen
to enter the new reservoir or host.
same as the portal of exits
– Respiratory tract, mucous membranes,
and gastrointestinal tract are common.
– injured skin
Chain of Infection
Susceptible Host – someone that is
capable of becoming infected.
– Microorganisms must be present in large
enough quantity to be virulent (and
cause disease).
– individuals with an immunity to certain
pathogens will not be susceptible
» Individuals can develop immunity from
either natural events, such as prior
exposure, or artificial events, such as
immunization
Signs & Symptoms of Infection
can occur when enough
pathogens invade a susceptible
host
Two types of infection:
– at a local site of injury
– generalized throughout the body
Signs & Symptoms of Infection
Local infections usually result from
injury to the skin
– Redness
– Swelling
– Tenderness
– Warmth
– drainage
Generalized infections are
accompanied by fever, malaise, loss of
appetite, swollen lymph nodes
Asepsis
aseptic techniques are used to keep an
area free of pathogens
Two types:
– Medical asepsis or “clean technique”
– Surgical asepsis or “sterile technique”
Medical Asepsis
used to maintain a clean environment
in order to reduce the number of
microorganisms
Common medical asepsis practices:
– hand washing
– using personal protective equipment
(PPE) like gloves
– routine cleaning of the environment
Surgical Asepsis
used to maintain a sterile environment
– no microorganisms or spores (cells
produced by bacteria)
areas in the operating room are sterile
to remain sterile, only sterile items can
come in contact with other sterile
items