Download 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
• 4. Found everywhere
in the environment,
including on and in
the human body
• 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
• 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
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
Congenital Syphilis
Secondary Syphilis
Primary Syphilis
Boils
• Antibiotics are used
to kill bacteria
• Some strains of
bacteria have be
come antibioticresistant
• Means that the
antibiotic is no longer
effective against the
bacteria
MRSA
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
Malaria
African Sleeping Sickness
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) athlete’s foot
• (3) histoplasmosis
• (4) yeast vaginitis
• (5) thrush
Athlete’s Foot
Thrush
Ringworm
• 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
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
Fleas, Ticks, Lice
Rocky Mountain spotted fever cycle
Typhus lesion
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
• 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
Herpes
Chicken pox
Mumps
Measles
• 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
• (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
• (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
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
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
• 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
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
• 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
• 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
• Opportunistic
• 1) Infections that occur when the
body’s defenses are weak
• 2) Diseases do not usually occur in
individuals with an intact immune
system
• 3) Examples include the development
of Kaposi’s sarcoma (a rare type of
cancer) or Pneumocystis carinii
pneumonia in individuals with AIDS
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
• 8. Immune response
• a. Body produces antibodies,
protective proteins that combat
pathogens
• b. Cells secrete protective
chemicals such as interferon
• 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