Infection Control: Efforts designed to
protect both the patient and care
provider.
Infectious Disease: Any illness
resulting from invasion of a host by
disease producing organisms such as
bacteria, viruses, fungi, or parasites.
Also known as: microbes
Small living plant/animal not visible to
naked eye
Found everywhere in the environment,
including in/on human body
Many microbes exist on or within us and do
not cause disease or infection (are called
non-pathogens)
Microbes that cause infection/disease are
called pathogens
Some microbes can be beneficial
(Normal Flora)in one body system &
become pathogenic in another
(ex. E-coli- normal in large intestine, causes
UTI in urinary)
5 types:
Bacteria
Protozoa
Fungi
Rickettsiae
Viruses
Simple one-celled organism that can
produce disease in a host, can
multiply outside of cells on surfaces or
objects.
Classified by shape and arrangement
Bacterium protected by a hard shell is
called a spore
3 main types: cocci, bacilli, spirilla
 Round/spherical in shape
 3 types:
Diplococci-occur in pairs or 2 circles,
causes gonorrhea, meningitis, &
pneumonia
2. Streptococci-occur in chains, causes
strep throat
3. Staphylococci-occur in clusters/groups,
causes boils, wound infections & toxic
shock, UTI’S
1.
Strep bacteria
Staphylococcus aureus (wound)
Rod shaped
Occur singly, in pairs, or in chains
Many have flagella(threadlike projections
like tails that allow them to move)
Ability to form spores or thick walled
capsules(extremely difficult to kill while in
spore form)
Can cause TB, tetanus, whooping cough,
botulism
Anthrax with white blood cells
Spiral or corkscrew in shape
Include corkscrew spirochete
Can cause syphilis and cholera
One celled animals
Found in decaying materials &
contaminated water
Some are pathogenic & cause malaria,
amebic dysentery, Pneumocystis Carini
Pneumonia (PCP), Trichomonas
Plasmodium: Malaria
 Simple plantlike organisms
Live on dead organic matter
Yeasts & molds are common forms of
pathogenic fungi
Can cause ringworm, athlete’s feet, &
histoplasmosis (systemic respiratory
infection)
 Parasitic microbe:
1. Cannot live outside the cells of another
living organism
2. Commonly found on fleas, ticks, & mites
3. Transmitted to humans by bites of these
insects
4. Can cause typhus fever & Rocky Mountain
spotted fever
Rocky Mountain Spotted Fever
Smallest microbe-only visible with electron
microscope
Cannot reproduce unless they are inside
another living cell
Spread mainly from human to human by
blood & body secretions
Very difficult to kill-resist most
disinfectants, not affected by antibiotics
Can cause common cold, flu, pneumonia,
measles, chickenpox, herpes, warts,
hepatitis B, HIV
Hepatitis B virus
Warm environment
Darkness-most are killed quickly in sunlight
Source of food & moisture
Need for oxygen varies- aerobic(need O2 to
live) anaerobic(don’t need O2)
Human body is ideal supplier of all of these
requirements
1. Some produce poisons (toxins) which
harm the body
2. Some cause an allergic reaction resulting
in watery eyes, runny nose & sneezing
3. Others attack & destroy the living cell
they invade ( ex. Malaria invades RBC &
causes it to rupture, HIV invades T-cells)
Factors that must exist for disease to occur.
Includes:
 1. Causative agent
 2. Reservoir
 3. Portal of exit
 4. Means of transmission
 5. Portal of entry
 6. Susceptible host
Chain of Infection
Causative Agent /
Pathogen
Host
Reservoir
Portal of Entry
Transmission
Portal of Exit
1. Causative agent- pathogen such as
bacteria or virus
2. Reservoir place- where causative agent
lives. Common reservoirs include human
body, animals, environment, and fomites
( objects contaminated with infectious
material that contains the pathogens, i.e.
pencil, desk, hand rail, etc.)
 A Human being or animal that is a
reservoir for microorganisms but is not ill
with infection/disease is a carrier or host.
(Example: HIV)
3.
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- pathogen must be
transmitted to another reservoir or host
where it can live.
 Five main routes of transmission:
1.
Contact- direct/indirect
2.
Droplet- propelled short distances
through air (flu)
3.
Airborne- remain suspended in air for
long periods of time ( TB, measles,
chicken pox)
4.
Five main routes of transmission:

4.
5.
Vectorborne – Insect bite (fleas/ticks)
Common Vehicle – pathogen
transmitted through items such as
surgical instruments, stethoscopes,
blood pressure equipment, etc.
Contact: According
to the CDC, this is
the most frequent method of disease
transmission in a hospital environment.
Direct- direct contact transmission from
one person to another through physical
contact. Indirect- transmission from one
person to another through an object
such as contaminated hands or medical
instruments (needle stick, dressings,
patient care items).
Patients under contact precautions should
be placed in a private room or in a room
with another patient who has the same
infection. If this is not possible, patient
placement will depend on the type of
infection and an infection control expert
should be consulted.
Gloves should be worn
Change gloves after handling potentially
infective material
Dispose of gloves before leaving room.
NEVER wear gloves in hallways or outside
patient’s room
A non-sterile gown should be worn when
entering the patient's room if clothing may
be contaminated.
Remove before leaving patients room
Avoid touching contaminated areas with
uniform/hands
Patient movement should be limited, but if
it is necessary, care should be taken not to
contaminate other patients and surfaces.
Whenever possible, patient care equipment
should be dedicated to a single patient or
group of patients with the same infection. If
this is not possible, the equipment must be
carefully disinfected after each use.
Droplet transmission - Occurs when an
infected patient expels droplets into the air
and the droplets land in the nasal cavity,
mouth, or conjunctiva. The droplets are
generated from coughing, sneezing,
talking, and by some medical procedures.
When you sneeze, millions of tiny droplets
are propelled from your mouth and nose.
The droplets fly through the air rather than
remaining suspended in the air. Measles,
mumps, rubella, and Severe Acute
Respiratory Syndrome (SARS) can all be
transmitted through droplet transmission.
Almost all common diseases may be spread
through droplet transmission.
Placed in a private room
Or room with patient who has the same
infection.
Three foot separation between the infected
patient and other people
It is not necessary to keep the door closed.
Health care personnel should wear a mask
and goggles
The patient should wear a mask if moved
Airborne transmission - when tiny particles
containing pathogens remain suspended in
the air for long periods of time.
Examples: Measles and chickenpox
One of the worst outbreaks of disease in
human history was the influenza pandemic
of 1918. Historians believe it began in
America.
At least 21 million people died, and possibly
as many as 50 million. Many of them
drowned to death when fluid from the
infection filled their lungs.
Some airborne pathogens can be spread in
the wind, and affect huge areas.
Placed in a private room or, if necessary,
OR:
In a shared room with another patient who
has an active infection of the same type.
 Door should be kept closed
Air circulation system must prevent spread
of unfiltered air to other areas
Negative Air Pressure System
Patient movement around the facility
should be minimized.
If the patient must be moved, he or she
should wear an N95 mask.
Everyone entering the room should wear a
N95 respirator.
Examples: pulmonary tuberculosis,
chickenpox,
A vector - organism that carries pathogens
from one host to another.
Examples: fleas, ticks, and rats. Malaria,
yellow fever, and bubonic plague are all
diseases that can be spread through
vectors.
This type of transmission occurs when
pathogens are spread to several hosts
through a single contaminated item such as
food, water, or surgical instruments.
Example E. coli spread through food.
5. Portal of entry- way to enter a new
reservoir or host
Different portals of entry:
Breaks in the skin or mucous membrane
Respiratory tract
Digestive tract
Genitourinary tract
Circulatory system
6. Susceptible host- individual who can
contract the disease
Most susceptible- elderly, newborns,
persons with weak immune systems,
persons with cancer
Humans become host when large numbers
of pathogens invade the body and body
defenses are weak
If any part of the chain can be eliminated,
the spread of disease/infection will be
stopped
Follow practices to interrupt or break this
chain (wash your hands)
Asepsis- absence of disease producing
microbes or pathogens
Common aseptic techniques: handwashing
& good personal hygiene, using disposable
gloves when contacting contaminated
objects, proper cleaning of instruments &
equipment
Handwashing: the single most effective way
to prevent the spread of pathogens
1. Antisepsis - prevent/inhibit the growth of
pathogenic organisms.
 Usually not effective against spores &
viruses
 Can be used on the skin
 Example; Alcohol & betadine
2. Disinfection - process that destroys or kills
pathogenic organisms
Used mainly on objects not people
Not always effective against spores &
viruses
Can irritate and damage the skin,
Example; Bleach solutions
3. Sterilization - process that destroys all
microorganisms both pathogenic and
nonpathogenic.
 Kills spores & viruses
 Steam under pressure, gas, radiation,
and chemicals can be used to sterilize
objects
 Autoclave is the most common piece
of equipment used for sterilization
CDC (Center for Disease Control) has
identified 2 levels for infection control.
 Standard Precautions
 Transmission-Based
Precautions
Goal: Keep pathogens within a specific area
 Standard precautions: treat all patients as
though they may be infected.
 Standard precautions combine the major
features of :
1. Universal Precautions - reduces the
risk of transmitting bloodborne
pathogens
2. Body-Substance Isolation (BSI)reduces the risk of transmitting
pathogens from moist body
substances
Wash hands:
 Before/after examining patients
 After contact with blood, body fluids &
contaminated items.
Wear gloves: if there could be contact with
blood, body fluids, mucous membrane, or
broken skin.
Remove gloves: Before going to another
patient, wash hands and put on new gloves.
Wear a mask protective eyewear and gown:
when splashes or sprays of body fluids are
likely.
Do not recap needles. EVER!
Clean and disinfect frequently touched
surfaces including beds, bed rails, patient
examination tables and bedside tables
Launder soiled linens and avoid direct
contact with soiled items
Use oral rather than injectable medications
whenever possible
Universal Precautions - introduced in 1985
as a response to the appearance of AIDS.
Treat all materials as though they are
infected with diseases such as HIV or HBV.
Use gloves and gowns, masks and eye
protection during medical procedures.
 Standard precautions include:
1. Protective work practices -
2.
3.
4.
5.
handwashing, handling sharps, good
hygiene
Use of personal protective equipment
(PPE) - gloves, gowns, face shields,
masks
Protective housekeeping (disinfectants)
Protection: Hepatitis B vaccination
Exposure reporting
Transmission-Based Precautions are used in
addition to standard precautions.
Categories include airborne, droplet,
contact
Place patient in private room
Keep their door closed
Wear masks & gloves to enter the room,
Move patient only for essential purposes
Have patient wear mask outside of the
room