2. Related terms
◦ Medical asepsis
◦ Includes all practices
intended to confine a
specific
microorganism to a
specific area
◦ Limits the number,
growth, and
transmission of
microorganisms
◦ Objects referred to as
clean or dirty (soiled,
contaminated)
◦ Surgical asepsis
◦ Sterile technique
◦ Practices that keep
an area or object free
of all microorganisms
◦ Practices that destroy
all microorganisms
and spores
◦ Used for all
procedures involving
sterile areas of the
body
3. ◦ Normal resident flora: microorganisms found in one part of
body and produce infection in another.
◦ Infection: is an invasion of body tissue by microorganisms
and their growth there.
◦ Infectious agent: microorganism that causes infection.
◦ Disease: a detectable alteration in normal tissue function.
◦ Virulence: the frequency with which a pathogen causes
disease.
4. ◦ Communicable disease: a condition caused by the
transmission of an infectious agent from one individual to
another by direct or indirect contact or as airborne
infection.
◦ Pathogenicity: is the ability to produce a disease, thus, a
pathogen is a microorganism that causes disease.
◦ Asepsis: is the freedom from disease-causing
microorganisms.
◦ Sepsis: is the state of infection (septic shock).
5. Factors Influencing Microorganism’s
Capability to Produce Infection
◦ Number of microorganisms present
◦ Virulence and potency of the microorganisms
(pathogenicity)
◦ Ability to enter the body
◦ Susceptibility of the host
◦ Ability to live in the host’s body
6. Factors Affecting Virulence
◦ Strength of pathogen to adhere to healthy cells.
◦ Ability of pathogen to damage cells or interfere with the
body’s normal regulating systems.
◦ Ability of pathogen to evade attack of white blood cells.
8. Types of infection
◦ Colonization: is the process by which strains of
microorganisms become resident normal flora (grow and
multiply without causing a disease)
◦ Infections can be Local or Systematic.
◦ Local infection: is limited to the specific part of the body
where the microorganisms remain.
◦ Systematic: when microorganisms spread and damage
different parts of the body (bacteremia/septicemia)
◦ Acute infections: appear suddenly or last short time
◦ Chronic infections: occur slowly, over a very long period,
and may last for months or years
9. Nosocomial Infections
◦ Infections that are usually associated with delivery of health
services.
◦ Examples:
◦ Urinary tract:
◦ Improper catheterization technique
◦ Contamination of closed drainage system
◦ Inadequate hand hygiene
◦ Surgical sites:
◦ Inadequate hand hygiene
◦ Improper dressing change technique
◦ Blood stream:
◦ Inadequate hand hygiene
◦ Improper intravenous fluid, tubing and site care technique
◦ Pneumonia:
◦ Inadequate hand hygiene
◦ Improper suctioning technique
10. Risks for Nosocomial Infections
◦ Diagnostic or therapeutic procedures
◦ Iatrogenic infections
◦ Compromised host
◦ Insufficient hand hygiene
11. Chain of infection
◦ Etiologic Agent
◦ Reservoir
◦ Portal of Exit from Reservoir (table 3/p. 675)
◦ Method of Transmission
◦ Portal of Entry to Susceptible Host
◦ Susceptible Host
13. Agent
◦ An entity capable of causing disease.
◦ These may be:
◦ Biological (bacteria, viruses, fungi, protozoa,
Rickettsia).
◦ Chemical (pesticides, food additives, medications,
industrial chemicals).
◦ Physical (environmental factors, like heat, light,
noise, radiation, and machinery).
14. Reservoir
◦ A place where the agent can survive. The most
common reservoirs are:
◦ Humans.
◦ Animals.
◦ Environment.
◦ Fomites (objects contaminated with an infectious
agent, e.g. bed pans, urinals, linens, instruments,
dressings, etc.).
15. Portal of Exit
◦ The route by which an infectious agent leaves the
reservoir to be transferred to a susceptible host.
Includes:
◦ Sputum from respiratory tract.
◦ Semen, vaginal secretions, or urine, from the genito-
urinary tract.
◦ Saliva and feces, from the gastrointestinal tract.
◦ Blood.
◦ Draining wounds.
◦ Tears.
16. Modes of Transmission
◦ The process that bridges the gap between the portal of
exit of the infectious agent from the reservoir or source
and the portal of entry of the susceptible “new” host.
◦ Includes:
◦ Contact transmission (direct contact with infected
person, indirect contact through fomite, or close
contact with contaminated secretions).
◦ Airborne transmission.
◦ Vehicle transmission (through contaminated substances
such as water, milk, drugs, or blood).
◦ Vectorborne transmission (through fleas, ticks, lice, and
other animals).
17. Host
◦ A simple or complex organism that can be affected
by an agent.
◦ A susceptible host lacks resistance to an agent and
is vulnerable to disease.
◦ A compromised host has impaired defense
mechanisms and is susceptible to infection.
19. Breaking the Chain of
Infection
Between Agent and Resevoir
◦ Cleansing.
◦ Disinfection.
◦ Sterilizing.
20. Cleansing
◦ The removal of soil or organic material from
instruments and equipment.
◦ Four steps:
◦ Rinsing the object under cold water.
◦ Applying detergent and scrubbing object.
◦ Rinsing the object under warm water.
◦ Drying the object prior to sterilization or disinfection.
◦ Cleaning: inhibits the growth of microorganisms.
When cleaning visibly soiled objects, nurses must
always wear gloves to avoid direct contact with
infections microorganisms.
21. Disinfection
◦ Disinfectants are chemical solutions which are
frequently caustic and toxic to tissues.
◦ Disinfectants used to destroy pathogens
(bactericidal, baceriostatic), except spores, from
inanimate objects.
◦ An antiseptic is a chemical preparation used on skin
or tissue. agent inhibit the growth of microorganism
◦ Germicides are chemicals that can be applied to
both animate (living) and inanimate objects for the
purpose of eliminating pathogens.
22. Sterilization
◦ The total elimination of all microorganisms
including spores.
◦ Instruments used for invasive procedures must be
sterilized.
◦ Moist heat or steam, radiation, chemicals, and
ethylene oxide gas used for sterilization.
◦ Autoclaving sterilization, using moist heat, is used
in most hospital settings.
23. Isolation precautions
◦ Isolation: measures that designed to prevent
transmission of infectious agent to health
professionals, clients, and visitors.
◦ Used for Compromised client: highly susceptible for
infection).
24. Disease-specific Isolation
Precautions
◦ Delineate practices for control of specific diseases
◦ Use of private rooms with special ventilation
◦ Cohorting clients infected with the same organism
◦ Gowning to prevent gross soilage of clothes
26. Universal Precautions (UP)
◦ Used with all clients
◦ Decrease the risk of transmitting unidentified
pathogens
◦ Obstruct the spread of bloodborne pathogens
(hepatitis B and C viruses and HIV)
◦ Used in conjunction with disease-specific or category-
specific precautions
27. Body Substance Isolation (BSI)
◦ Employs generic infection control precautions for all
clients
◦ Body substances include:
◦ Blood
◦ Urine
◦ Feces
◦ Wound drainage
◦ Oral secretions
◦ Any other body product or tissue
28. Standard Precautions
◦ Used in the care of all hospitalized persons regardless
of their diagnosis or possible infection status
◦ Apply to
◦ Blood
◦ All body fluids, secretions, and excretions except
sweat (whether blood is present or visible)
◦ Nonintact skin and mucous membranes
◦ Combine the major features of UP and BSI
29. Transmission-based Precautions
◦ Used in addition to standard precautions
◦ For known or suspected infections that are spread in
one of three ways:
◦ Airborne
◦ Droplet
◦ Contact
◦ May be used alone or in combination but always in
addition to standard precautions
31. Breaking the Chain of Infection
Between Reservoir and Portal
◦ Proper Hygiene
◦ Clean Dressings
◦ Clean Linen
◦ Clean Equipment
32. Breaking the Chain of Infection
Between Portal of Exit and Mode of Transmission
◦ Clean dressings on all injuries.
◦ Clients should be encouraged to cover the mouth
and nose when sneezing or coughing, as should
the nurse.
◦ Gloves must be worn whenever necessary.
◦ Proper disposal of contaminated items.
33. Breaking the Chain of Infection
Between Mode of Transmission and Portal of Entry
◦ Nurses wearing barrier protection (gloves, masks,
gowns, goggles).
◦ Proper handwashing.
◦ Proper disposal of contaminated equipment and
linens.
34. Breaking the Chain of Infection
Between Portal of Entry and Host
◦ Maintaining skin integrity.
◦ Using sterile technique for client contacts.
◦ Avoiding needle sticks.
◦ Proper disposal of sharps.
35. Breaking the Chain of Infection
Between Host and Agent
◦ Proper nutrition.
◦ Exercise.
◦ Immunization.
36. Portal of exit
◦ Avoiding talking, coughing, or sneezing over
open wounds or sterile fields
◦ Covering the mouth and nose when coughing
or sneezing
Breaking the Chain of Infection
37. Method of transmission
◦ Direct transmission
◦ Indirect transmission
◦ Airborne transmission:
◦ Droplets
◦ Dust
38. Direct transmission
◦ Involves immediate and direct transfer of
microorganisms from person to person through
touching, biting, kissing, or sexual intercourse.
◦ Droplet spread is also a form of direct
transmission.
◦ Sneezing, coughing, spitting, singing, or talking
are ways of projecting droplet spray.
39. Indirect transmission
◦ It may be:
◦ Vehicle-borne transmission
◦ Vector-born transmission
◦ A vehicle born: is any substance that serves as
intermediate means to transport and introduce an
infectious agent into a susceptible host via suitable
portal of entry (e.g. handkerchiefs, toys, soiled
clothes, cooking or eating utensils, and surgical
instruments or dressings, water, food, blood, serum,
and plasma).
◦ A vector born: is an animal or flying or crawling
insect that serves as an intermediate means of
transporting the infectious agent.
40. Normal Defense Mechanisms
◦ A host’s immune system serves as a normal
defense mechanism against the transmission of
infectious agents.
◦ Immune system recognizes presence of antigens,
foreign proteins that cause the formation of an
antibody.
41. Body defences against
infection
◦ Nonspecific Defences:
◦ Anatomic and Physiological Barriers
◦ Inflammatory Response
◦ Vascular and Cellular Response
◦ Exudates Production
◦ Reparative Phase
◦ Specific Defences:
◦ Antibody-mediated defences
◦ Cell mediated defences
42. Anatomical and physiologic
barriers
◦ Intact skin and mucous membranes
◦ Nasal passage (moist mucous membranes & cilia)
◦ Phagocytes (lung)
◦ Oral shedding of mucosal epithelium
◦ Microbial inhibitors in saliva (lactoferrin, lysozymes)
◦ Eyes (tears)
◦ High acidity of stomach
◦ Alveolar macrophages
◦ Resident flora of the large intestine
◦ Peristalsis
◦ Low pH of the vagina
◦ Urine flow through the urethra
43. Inflammation
◦ A nonspecific cellular response to tissue injury.
◦ Characteristics include:
◦ Redness (erythema)
◦ Heat
◦ Pain
◦ Swelling (edema)
◦ Loss of function
◦ Pus (purulent exudate)
44. Inflammatory response
The Three Stages of Inflammation
◦ Phase 1: Inflammatory Response
◦ Healing of acute injuries begins with the acute vascular
inflammatory response. The purpose of vascular changes is to
increase blood flow to the local area, mobilize and transport
cells to the area to initiate healing. The damaged cells are
removed and the body begins to put new collagen in the area
of injury. This phase is initiated immediately after injury and lasts
3-5 days.
◦ Signs and Symptoms:
◦ Pain, warmth, swelling, palpable tenderness, limitation in joint or
muscle range of motion
◦ Treatment focus:
◦ Decrease pain and swelling, prevent chronic inflammation, maintain
mobility and strength in adjacent areas while injured areas are rested
45. ◦ Phase 2: Repair and Regeneration
◦ The second phase is characterized by new collagen
formation. New collagen fibers are laid down in a
disorganized manner in the form of a scar and there
are weak links between each fiber. Thus, the new
tissue is weak and susceptible to disruption by overly
aggressive activity. This phase lasts from 2 days to 8
weeks.
◦ Signs and Symptoms:
◦ Less warmth and swelling, palpable tenderness
decreases, pain felt with tissue resistance or
stretch of the tissue
◦ Treatment focus:
◦ Range of motion exercises, joint mobilization, scar
mobilization to produce a mobile scar, light loads
to promote tissue remodel
46. ◦ Phase 3: Remodelling and Maturation
◦ As healing progresses, the tissue continues to remodel,
strengthen and improve its cellular organization. There is
less new collagen formation, but increased organization
of the collagen fibers, and stronger bonds between
them. Tension becomes important because new
collagen must orient along the lines of stress to best
accommodate the loads required for function. The end
of tissue remodelling is unknown and may take months
to years for completion.
◦ Signs and Symptoms:
◦ Improved range of motion and strength
◦ Treatment focus:
◦ Stretching, active contraction, resistive loads
47.
48.
49. mechanisms of immunity
◦ There are two main mechanisms of immunity within the
adaptive immune system – humoral and cellular.
◦ Humoral immunity is also called antibody-mediated immunity.
With assistance from helper T cells, B cells will differentiate into
plasma B cells that can produce antibodies against a specific
antigen. The humoral immune system deals with antigens from
pathogens that are freely circulating, or outside the infected
cells. Antibodies produced by the B cells will bind to antigens,
neutralizing them, or causing lysis (dissolution or destruction of
cells by a lysin) or phagocytosis.
◦ Cellular immunity occurs inside infected cells and is mediated
by T lymphocytes. The pathogen's antigens are expressed on
the cell surface or on an antigen-presenting cell. Helper T cells
release cytokines that help activated T cells bind to the
infected cells’ MHC-antigen complex and differentiate the T
cell into a cytotoxic T cell. The infected cell then undergoes
lysis.
50. Active and Passive Humoral
Immunity
◦ The humoral immune response is the aspect of immunity
mediated by secreted antibodies.
51. Passive Immunity
◦ Host receives natural or artificial antibodies produced from
another source
◦ Natural passive immunity
◦ Passive immunity is the transfer of active humoral immunity
in the form of ready-made antibodies from one individual
to another.
◦ Antibodies transferred naturally from an immune mother
to baby through the placenta or in colostrums
◦ Lasts 6 months to 1 year
◦ Artificial passive immunity
◦ Artificially-acquired passive immunity is a short-term
immunization achieved by the transfer of antibodies, and
can be administered in several forms
◦ Occurs when immune serum (antibody) from an animal or
another human is injected.
◦ Lasts 2 to 3 weeks
52. Active Immunity
◦ Host produces antibodies in response to natural antigens or artificial
antigens
◦ Active immunity is long-lasting immunity produced by the body’s
own immune system and involves the production of long-lasting
memory cells.
◦ Active immunity can either be natural, such as from an infection, or
artificial, such as from vaccination.
◦ Natural active immunity
◦ Antibodies are formed in presence of active infection in the body
◦ Duration lifelong
◦ Artificial active immunity
◦ Antigens administered to stimulate antibody formation
◦ Lasts for many years
◦ Reinforced by booster
53.
54. Assessment
◦ History of :
◦ Client is risk to develop infection
◦ Impaired physical mobility
◦ Imbalance nutrition
◦ Physical assessment
◦ Localized infection
◦ Localized swelling ,redness, tenderness ,hotness,
loss of function
◦ Systematic infection:
◦ Fever, tachycardia, tachypnoea, malaise,
anorexia, lymph node enlargement
55. ◦ Laboratory data :
◦ Elevated WBC (The normal number of WBCs in the blood is
4,500 to 11,000 WBCs per microliter).
◦ Elevated differential WBC count (neutrophils,
lymphocytes, monocytes, eosinophils & basophils)
◦ Elevated Erythrocyte Sedimentation Rate (ESR)
◦ Cultures (urine, blood, sputum, drainage)
◦ White blood cells are an important part of your body’s
immune system. They’re responsible for protecting your
body against infections and invading organisms.
◦ An ESR test can help determine if you have a condition
that causes inflammation. These include arthritis,
vasculitis, or inflammatory bowel disease.