Bell Work 11/9
 Do you know what types of medication you take if you have a
ear or eye infections?
 Antibiotics
 Antivirals
 Do you know two types of microorganisms that cause illness?
 Bacteria
 Viruses
 Protozoa
 Fungi
 And more
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Unit 13 Infection Control
13:1 Understanding the Principles of
Infection Control
 Understanding is essential to all health care
workers
 Provide a basic knowledge of how disease is
transmitted
 Goal is prevention of disease
3
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Microorganisms or
Microbes
 Small living organisms
 Not visible to the naked eye
 Microscope must be used to see them
 Found everywhere in the environment
 Found on and in the human body
 Many are part of normal flora of body
 May be beneficial
4
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Microorganisms or
Microbes (continued)
 Called nonpathogens when not harmful to the body
 Some cause infections and disease
 Called pathogens when able to harm the body
 Sometimes nonpathogenic microorganisms can become
pathogenic
 E Coli
 Staphylococcus
5
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Microbe Classifications
 Bacteria
 Protozoa
 Fungi
 Rickettsiae
 Viruses
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Bacteria
 Simple, one-celled
organisms
 Multiply rapidly
 Classified by shape and
arrangement
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Bacteria – Cocci
 Round or spherical in shape
 Diplococci cause gonorrhea, meningitis, and pneumonia
 Streptococci cause strep throat and rheumatic fever
 Staphylococci cause boils, wound infections, and toxic
shock
8
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Bacteria – Bacilli
 Rod-shaped
 Occur singly, in pairs, or in chains
 May have flagella
 Diseases caused by bacilli include tuberculosis, tetanus,
pertussis, and diphtheria.
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Bacteria – Spirilla and Spirochetes
 Spiral or corkscrew shape
 Some spirochetes live in
water others are ticks and
lice
 Diseases include Lyme
disease (spirochete),
syphilis, and cholera
(spirilla).
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Antibiotics
 Antibiotics are used to kill bacteria
 Some strains of bacteria have become antibiotic-resistant
 When antibiotic-resistant, the antibiotic is no longer effective
against the bacteria
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Protozoa
 One-celled, animal-like
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organism
Found in decayed materials
and contaminated water
May have flagella for
movement
Some are pathogenic
Protozoa infection causes
malaria, amebic dysentery,
and trichomonas
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Fungi
 Simple, plant-like
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13
organisms
Live on dead organic
matter
Yeast and molds are two
forms that can be
pathogenic
Ringworm, athletes foot,
and trush are from fungi
Antibiotics do not kill
Antifungal medications
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Rickettsiae
 Parasitic microorganisms
 Cannot live outside the cells of another living organism (a
host)
 Transmitted to humans by the bites of insects (e.g., fleas, lice,
ticks, mites)
 Rickettsiae causes typhus, and rocky mountain spotted fever
 Antibiotics are effective against some
14
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Viruses
 Smallest microorganisms
 Must use electron
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microscope to see
Must be inside another
living cell
to reproduce
Spread by blood and body
secretions
Very difficult to kill
Hepatitis, HIV, chicken
pox, influenza and polio
are some diseases that are
spread by a virus.
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Virus – Hepatitis B
 Transmitted by blood and
body secretions
 Affects the liver –
 hepat/liver
 itis/inflammation
 Can survive several days in
dried blood
 Vaccine available for
protection
 Most children in the state
of Alaska have been
immunized against Hep. B
16
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Hepatitis C
 Transmitted by blood and
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blood-containing body fluids
Can survive several days in
dried blood
Many infected individuals
don’t feel sick
Others have mild symptoms
Can cause severe liver
damage
Currently, no vaccine ready
for use
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Acquired Immune Deficiency Syndrome
(AIDS)
 Caused by the Human
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Immunodeficiency Virus
(HIV )
Suppresses the immune
system
Individual becomes
susceptible to cancers and
infections that would not
affect a healthy person
No cure and no vaccine
Understanding Viruses
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Growth of
Microorganisms
 Most prefer warm environments
 Most prefer darkness
 Need source of food and moisture
 Need for oxygen varies
 Human body is ideal supplier for all the things listed above
19
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How Pathogens Cause
Infection and Disease
 Some produce poisons
called toxins
 Some cause an allergic
reaction
 Others attach and destroy
the living cells they invade
20
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Classifications of
Diseases and Infections
 Endogenous
 Originates within the body
 Examples: metabolic
disorders, congenital
abnormalities, tumors, and
infections caused by
microorganisms within the
body
 Exogenous
 Originates outside the body
 Examples: radiation, chemical
agents, trauma, electric
shock, and
temperature extremes
21
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Classifications of Diseases and Infections
 Nosocomial
 Acquired in a health care
facility
 Many are antibiotic-resistant
(MRSA)
 Can cause serious and even
life-threatening infections
 Opportunistic
 Infections that occur when the
body’s defenses are down
 Usually do not occur in normal
immune system
 Examples: Kaposi’s sarcoma
(rare type of cancer) and
Pneumocystis carinii pneumonia
in individuals with AIDS
22
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Bell work 11/14, 11/15
 What type of infection originates in a medical facility?
 What type of infection occurs when the bodies defenses are
down?
 What is the best thing you can do to keep from getting sick?
23
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 Must be present for disease to
occur and spread from one
individual to another
 Causative agent
 A pathogen
 Reservoir
 Where it can live
 Portal of exit
 Way to escape the reservoir
 Mode of transmission
 Way it can be transmitted
 Portal of entry
 How it enters the new host
 Susceptible host
 Person who is likely to get sick
24
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Chain of Infection
Common Body Defenses
 These things help us from
getting sick
Mucous membranes
Cilia
Coughing and sneezing
HCL in the stomach
Tears
Fever
Inflammation response –
leukocytes
 Immune response –
antibodies and
cell secretion
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25
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Ending the Chain
of Infection
 Eliminate any step in the
chain and infection is
stopped
 Follow practices to
interrupt or
break the chain
 Remember, pathogens are
everywhere
 Prevention is a continuous
process
26
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