Download Chapter 12: Infection Control

Learning Goals:
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Understand principles of infection control are essential to all
healthcare workers
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Provide a basic knowledge of how disease is transmitted
Main emphasis on prevention of disease
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Microbes – small living organisms
 Invisible 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 the normal Flora of body
May be beneficial in maintaining body processes
Flora – plant life for living in a specific environment
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Called non-pathogens when not harmful to the body
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Some cause infections and disease
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Called pathogens (germs) when able to harm the body
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Sometimes non-pathogenic microorganisms can become pathogenic
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Bacteria
Protozoa
Fungi
Rickettsiae
Viruses
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Simple one celled organism
Multiply rapidly
Classified by shape and arrangement
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Round or spherical in shape
Diplococcic (pairs of cocci)
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Streptococci (chain of cocci)
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Gonorrhea, meningitis, pneumonia
Strep throat, rheumatic fever
Staphylococci (clusters, or groups of cocci)
Boils, wound infections, toxic shock
 Pus producing
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Rod Shaped
Occur singly, in pairs or in chains
May have flagella (tail-like)
Projections that allow it to move
Ability to form spores
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Ex: TB, tetanus, whooping cough, typhoid
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Spiral or corkscrew shape
Includes comma-shaped vibrio and corkscrew spirochete
Disease include syphilis and cholera
(Vibrio- common in food borne infection, eating under cooked
seafood)
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Used to kill bacteria
Some strains of bacteria have become anti-biotic resistant
When anti-biotic resistant, the antibiotic is no longer effective against
the bacteria
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One celled, animal like organism
Found in decayed materials and contaminated water
May have flagella for movement
Some are pathogenic (infectious agent leading to sickness in host)
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Simple plant like organism
Live on dead and organic matter
Yeast and molds
Can be pathogenic
Antibiotics do not kill
Antifungal medications
Athlete’s foot, yeast infections
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Parasitic Microorganisms
Can not live outside cells of another organism
Transmitted to humans by the bites of insects (ie: fleas, lice, ticks, mites)
Antibiotics are effective against them
Typhus fever, Rocky mountain spotted fever - tick borne disease that can be
fatal in humans
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Smallest of microorganism
Must use electron microscope to see
Must be inside another living cell to reproduce
Spread human to human by blood or body secretions
Difficult to kill
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Don’t respond to antibiotics
Resistant to disinfectants
Cause many diseases in humans – Hepatitis & AIDS
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Ideal environment: warm, dark, moist
Need source of food and moisture
Need for oxygen varies
Human body is ideal supplier of all requirements
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Some produce poisons called
toxins
Some cause allergic reactions
Others attack and destroy the
living cells they invade
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Endogenous – originates inside body
Exogenous – originates outside of body
Nosocomial – Infection inquired in Healthcare
facility
Opportunistic – Infections that occur when
the body’s immunity is suppressed or weak
Causative (Infectious) agent
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Pathogen must be present
Examples include bacteria
Reservoir
2.
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Place where causative agent can live
Examples: human body, animals and the environment
Portal of Exit
3.
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Way for causative agent to escape from the reservoir
Examples: urine, feces, saliva, blood, tears, mucous discharge, sexual secretions
and draining wounds
4. Mode of Transmission
 Must be transmitted to another reservoir or host where it can live
 Direct Contact: spread by physical (hands) or sexual contact
 Indirect Contact: from contaminated substances to the person (food,
air droplets, insects, clothing, instruments
5. Portal of Entry
 Way to enter a new reservoir or host
 Examples: breaks in skin or mucous membranes, respiratory tract,
circulatory system, genitourinary tract
6. Susceptible Host
 Individual who can contract the disease
 If a larger number of pathogens invade the body or the body defenses
are weak, then the individual (susceptible host) can become sick with
infection or disease
If any part of the chain of infection is broken, the spread of disease or
infection can be stopped
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Mucous Membranes
Cilia
Coughing & Sneezing
HCL (hydrochloric acid) in stomach
Tears
Fever
Inflammation response – leukocytes
Immune response – antibodies and cell secretion
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Eliminate any step in the chain of infection
Follow standard practices to interrupt or break chain
Remember pathogens are everywhere
Prevention is a continuous process
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Major way to break the chain of infection
Asepsis: absence of disease-producing microorganisms or pathogens
Contaminated: any object or area that may contain pathogens
Major Goal: maintaining cleanliness and eliminating or preventing
contaminations
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Hand Washing
Good personal Hygiene
Disposable gloves
Proper cleaning of instruments and equipment
Thorough cleaning of environment
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Prevent or slow growth of pathogenic organisms
Not effective against spores and viruses
Used on skin
Examples: Alcohol and betadine
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Destroys or kills pathogenic organisms
Not always effective
Chemical disinfectants are used
Can irritate or damage skin
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Used on objects not people
Examples : Bleach solution
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Destroys all microorganisms
Steam under pressure, gas radiation and chemicals
Autoclave is the most common
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Important for healthcare workers to
know and use proper aseptic
techniques
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Prevents spread and transmission of
diseases