PRINCIPLES OF INFECTION CONTROL. MICROORGANISM OR MICROBE 1. Small living organism 2. Not visible to...
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PRINCIPLES OF INFECTION CONTROL
PRINCIPLES OF INFECTION CONTROL. MICROORGANISM OR MICROBE 1. Small living organism 2. Not visible to the naked eye 3. Must be viewed under a microscope
MICROORGANISM OR MICROBE 1. Small living organism 2. Not
visible to the naked eye 3. Must be viewed under a microscope 4.
Found everywhere in the environment, including on and in the human
body
Slide 3
Many microorganisms are part of normal flora of the body; flora
is microbial organisms in environment such as the intestinal,
vaginal, oral, or urinary systems a. Beneficial in maintaining
certain body processes b. Called nonpathogens
Slide 4
Other microorganisms cause infection and disease a. these are
called pathogens or germs At times, a microorganism that is
beneficial in one body system can become pathogenic in another body
system a. Bacteria called Escherichia coli (E. coil) is part of the
natural flora of the large intestine b. If E. coli enters urinary
system, it causes an infection
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CLASSIFICATION OF MICROORGANISMS Bacteria a. Simple one-celled
plants that multiply rapidly b. Classified by shape and arrangement
c. Some diseases caused by bacteria: (1) meningitis (2) gonorrhea
(3) boils (4) wound infections (5) typhoid (6) syphilis
Antibiotics are used to kill bacteria Some strains of bacteria
have be come antibiotic- resistant Means that the antibiotic is no
longer effective against the bacteria MRSA
Slide 9
PROTOZOA a. One-celled animal-like organism b. Often found in
decayed materials and contaminated water d. Some protozoa are
pathogenic and cause diseases such as: (1) malaria (2) amebic
dysentery trichomonas (3) African sleeping sickness
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Malaria African Sleeping Sickness
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FUNGI Simple plantlike organisms Live on dead organic matter
Yeasts and molds are two common forms of fungi that can be
pathogenic Cause diseases such as: (1) ringworm (2) athletes foot
(3) histoplasmosis (4) yeast vaginitis (5) thrush
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Athletes Foot Thrush Ringworm
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Antibiotics do not kill fungi Antifungal medications are
available for many of the pathogenic fungi These medications are
expensive, must be taken internally for a long period of time, and
may cause liver damage
Slide 14
RICKETTSIAE Parasitic microorganisms (1) Cannot live outside
the cells of an other living organism (2) Commonly found on fleas,
lice, ticks, and mites (3) Transmitted to humans by the bites of
these insects Cause diseases such as: (1) typhus fever (2) Rocky
Mountain spotted fever Antibiotics are effective against many
different rickettsiae
VIRUSES Smallest microorganisms, visible only in an electron
microscope Cannot reproduce unless they are inside another living
cell Spread from human to human by blood and body secretions
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Very difficult to kill (1) Resistant to many disinfectants (2)
Not affected by antibiotics Cause many diseases such as: (1) common
cold (2) measles (3) mumps (4) chicken pox (5) herpes (6) influenza
(7) polio
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Chicken pox Measles Herpes Mumps
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Three diseases of major concern to health care workers (1)
Hepatitis B or serum hepatitis Caused by the HBV virus Transmitted
by blood serum and body secretions Affects the liver and can lead
to destruction and scarring of liver cells Vaccine has been
developed to protect individuals from this disease Vaccine is
expensive and involves a series of three injections Under federal
law, employers must provide the vaccination at no cost to any
health care worker with occupational exposure to blood or other
body secretions Individual does have the right to refuse the
vaccination, but a written record must be kept proving that the
vaccine was offered
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(2)Hepatitis C Caused by the hepatitis C virus, or HCV
Transmitted by blood and blood containing body fluids Many
individuals who contact the disease are asymptomatic (display no
symptoms) Others have mild symptoms that are often diagnosed as
influenza or flu HCV can cause serious liver damage At present
there is no preventive immunization, but a vaccine is being
developed Both HBV and HCV are extremely difficult to destroy
Viruses can even remain active for several days in dried blood
Health care workers must take every precaution to protect
themselves from hepatitis viruses
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(3)Acquired immune deficiency syndrome (AIDS) Caused by the HIV
(Human Immunodeficient Virus) Suppresses the immune system
Individual cannot fight off many cancers and infections that would
not affect a healthy person No cure at present and no vaccine
available
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FACTORS REQUIRED FOR GROWTH: 1. Microorganisms need certain
things to grow and reproduce 2. Most microorganisms prefer a warm
environment, and body temperature is ideal 3. Darkness is also
preferred by most microorganisms, and many are killed quickly by
sunlight 4. Source of food and moisture is needed 5. Need for
oxygen varies a. Aerobic organisms require oxygen to live b.
Anaerobic organisms live and reproduce in absence of oxygen 6.
Human body is ideal supplier of all of the requirements
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HOW DO PATHOGENIC ORGANISMS CAUSE DISEASE? PATHOGENIC
MICROORGANISMS CAUSE INFECTION AND DISEASE IN DIFFERENT WAYS: 1.
Some pathogens produce poisons, called toxins, which harm body a.
Example is bacillus tetanus b. Produces toxins that damage central
nervous system
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2. Some pathogens cause an allergic reaction resulting in a
runny nose, watery eyes, and sneezing 3. Other pathogens attack and
destroy the living cells they invade a. Example is the protozoan
that causes malaria b. Invades red blood cells and causes them to
rupture
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CLASSIFICATIONS OF DISEASES AND INFECTIONS Classified as
endogenous, exogenous, nosocomial, and opportunistic Endogenous 1)
Means the infection or disease originates within the body 2).
Includes metabolic disorders, congenital abnormalities, tumors, and
infections caused by microorganisms within the body
Slide 26
Exogenous 1) Means that the infection or disease originates
outside the body 2) Examples include pathogenic organisms that
invade the body, radiation, chemical agents, trauma, electric
shock, and temperature extremes
Slide 27
Nosocomial 1) Infections acquired by an individual in a health
care facility, such as a hospital or long-term care facility 2)
Usually present in facility and transmitted by health care workers
to the patient 3) Many of the pathogens transmitted in this manner
are antibiotic-resistant 4) Can cause a serious and even
life-threatening infection 5) Common examples: (a) Staphylococcus
(b) Pseudomonas (c) Enterococci 6) Infection control programs are
used in health care facilities to prevent and deal with nosocomial
infections
Slide 28
Opportunistic 1) Infections that occur when the bodys defenses
are weak 2) Diseases do not usually occur in individuals with an
intact immune system 3) Examples include the development of Kaposis
sarcoma (a rare type of cancer) or Pneumocystis carinii pneumonia
in individuals with AIDS
Slide 29
COMMON BODY DEFENSES 1. Mucous membrane that lines the
respiratory, digestive, and reproductive tract and traps pathogens
2. Cilia (tiny, hairlike structures) lining the respiratory tract
to propel pathogens out of the body 3. Coughing and sneezing 4.
Hydrochloric acid in the stomach to destroy pathogens 5. Tears in
the eye that contain bacteriocidal (killing bacteria) chemicals 6.
Fever 7. Inflammation resulting in leukocytes or white blood cells
destroying pathogens
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8. Immune response a. Body produces antibodies, protective
proteins that combat pathogens b. Cells secrete protective
chemicals such as interferon
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9. Human becomes susceptible host in some instances a. Large
numbers of the pathogen invade the body b. Body defenses are weak
10. Ending the chain of infection a. If any part of the chain can
be eliminated, the spread of disease or infection will be stopped
b. Follow practices to interrupt or break this chain c. Prevent the
transmission of disease d. Important to remember that pathogens are
everywhere e. Preventing pathogen transmission is a continuous
process