DISEASE

Causes of Disease

MICROORGANISM

Indirect

Pathogenic

Nonpathogenic or Commensals

Direct

1. BACTERIA

A. COCCI

1. STREPTOCOCCI

2. STAPHYLOCOCCI (PYOGENIC)

3. DIPLOCOCCI

B. BACILLI

C. SPIROCHETE

2. FUNGI

3. RICKETTSIAE

4. PROTOZOA

6. HELMINTHS

7. VIRUSES

5. MYCOPLASMA

TYPES OF ASEPSISTYPES OF ASEPSIS

MEDICAL

SURGICAL -- it is said to have no living organism in or on the object

TYPES OF STERILIZATION

-- prevents spread of disease from one person to another.

A. BOILING

B. GAS AUTOCLAVE

C. STEAM AUTOCLAVE

D. CHEMICAL DISINFECTANTS

E. HEAT

F. IONIZING RADIATION

What nursing measure is considered the most important way to prevent the spread of infection? HandwashingHandwashing

TRANSMISSION OF INFECTION

Reservoir -- any environment that an organism can survive and reproduce

-- Fomite -- inanimate objects

1. Carrier

2. Healthy carrier

3. Convalescent carrier

4. Incubatory carrier

When are you the most contagious? Why?

Portal of Exit

--Vector-- an insect or animal that transfers an infectious agent from one host to another

Portal of Entry

-- Most infectious agent are restricted to only one portal of entry

Mode of Transmission

1. Direct contact

2. Indirect contact

3. Droplet

4. Vectors

Susceptibility of the Host-- age

-- nutrition

-- presence of other diseases

-- host’s immune system

Resistance to infection

-- influenced by:-- age

-- state of nutrition

-- hormones

-- adequate blood supply to infected area

-- location of the infection

-- effective immune system

VIRULENCE -- how powerful the organism is to produce disease

CHAIN OF INFECTION

Body’s Defense Mechanism

1. Skin and Mucus MembranesUnbroken skin – first line of defense

-- skin is acidic-- normal flora

Mucus membranes-- normal flora-- cilia

2. Lysozymes and Gastric Juices Lysozymes – present in tears, saliva,

mucus, skin and some internal body fluids

Gastric juices are strongly acidic

3. 3. Natural ReflexesNatural Reflexes

-- Sneezing, coughing, vomiting, and diarrhea

4. Interferon-- protein produced by WBC’s in

response to viral infection

-- triggers infected cells to produce anti-viral protein

-- inhibits cell reproduction

5. Reticuloendothelial System-- provides humoral immunity

(antibodies)IgG IgA IgM IgD IgE

-- cellular immune response (T- lymphocytes)--Phagocytosis -- fever

Nonspecific Immune Response

Signs & Symptoms – heat, redness, swelling & occasionally painFunction:

1. Contain & localize infection

2. Bring nutrients for tissue repair 3. Destroy microorganisms 4. Remove debris

1. VASCULAR RESPONSE a. Vasoconstriction followed by vasodilation b. Release of Histamine c. Heat and redness now apparent2. FLUID EXUDATE a. H2O, protein, glucose, electrolytes move into interstitial spaces. b. Causes swelling & pain c. Function 1. Brings more nutrients to site for healing 2. Dilutes bacterial toxins 3. Transports cells needed for phagocytosis3. CELLULAR EXUDATE ---White blood cells move into area to kill any microorganisms & to remove debris.----Either healing occurs or if inflammatory

response is not successful, the infection spreads

Nonspecific defense First-line barriers

Skin & mucous membranes

Fluids Chemicals

Nonspecific defenseSecond-line barriersChemical actioncomplement &interferon

Phagocytosis Inflammation

Specific defenseLymphocytes & macrophages

Cell-mediated immunity

Antibody-mediated immunity

Complements -- a group of proteins in the blood that influence the inflammatory process & serve as mediator in the antigen-antibody reaction

Invasion by Invasion by PathogensPathogens

What is the difference between and infection and an inflammation?

-- Infection – invasion of the body by a microorganism

-- Inflammation – the body’s response to an invasion or trauma

Three things happen when an organism enters the body:

1. Body will eliminate the pathogen

2. The pathogen will reside without disease

3. The pathogen will cause an infectious disease

Identification of OrganismsIdentification of Organisms

Skin Test – Patch Test – Interdermal Test

--Material injected intradermally & reaction is read in 48 to 72 hours

-- Positive reaction means organism has entered the body, but does not mean you are actively infected.

-- Done for Histoplasmosis, mumps, diphtheria, tuberculosis

CBC, WBC, and Differential Count

ESR (erythrocyte sedimentation rate or Sed rate) -- indicates inflammatory process

Immunologic Tests

-- Agglutination (clumping) Certain bacteria added to a

patient’s serum will cause clumping due to the presence of antibodies

--Precipitation TestsA solution of antigens and

antibodies in the right concentration will cause a white line to appear in the test tube

Indicates patient has antibodies to a particular antigen.

Used to detect antibodies to tetanus, diphtheria, & Scarlet Fever

Criminology labs use it to know if a particular blood stain is from an animal or a human

-- ImmunofluorescenceDye is attached to an

antibody & when the antibody-antigen reaction occurs, it will show up under an ultraviolet microscope

Used to detect syphilis & streptococcus

-- Tissue Biopsy Viruses can only be studied by

growing them in living tissue

--DrainageDirect Examination

Coagulase Test

-- Test to see if an enzyme produced by a bacteria produces a thrombus

-- If positive, organism is considered more virulent

--CulturesPlacing a small amount of a

specimen on a special growth medium

-- Acid FastDye applied to smear on slideIf color remains, organism is

considered Acid Fast.

leprosy

tuberculosis

--Gram StainStaining process involves 4 steps

using Crystal Violet, Gram’s Iodine solution, Alcohol, & Safranin

Gram negative if stained redanthrax

Gram positive if retain purple stain

staphylococcus

Gram-Positive Bacteria

Clostridium difficile Pseudomenbranous colitis

Staphylococcus aureus Pneumonia, toxic shock, cellulitis, boils, post-op peritonitis

Staphylococcus epidermis IV line-related phlebitis, post-op bone & joint infections

Streptococcus pneumoniae Pneumonia, meningitis, otitis media, sinusitis, septicemia

Steptococcus pyogenes Scarlet fever, impetigo, rheumatic fever

Steptococcus viridans Endocarditis

Gram-Negative Bacteria

Campylobacter jejuni Diarrhea (worldwide cause)

Escherichia coli Urinary tract, pylonephritis, septicemia, gastroenteritis, peritonitis

Haemophilus influenzae Pneumonia, meningitis

Klebsiella pneumoniae Pneumonia

Legionella pneumophilia Legionnaire’s Disease

Neisseria gonorrhoeae Gonorrhea

Neisseria Meningococcus Meningitis (most common cause)

Pseudomonas aeruginosa Wound, urinary tract, pneumonia, IV line infections

Salmonella enteritidis Gastroenteritis, food poisoning

Salmonella typhi Typhoid fever

Communities prevent the outbreak of disease by:

1. Isolation

2. Quarantine

3. Setting standards

4. Vector control

5. Giving authority to Occupational Safety & Health Administration (OSHA) & Washington Industrial Safety and Health Act (WISHA)

What cells in the bone marrow are capable of producing many different types of blood cells? Stem Cells

How are allergies and immunity similar?

Both result in antibody formation

Cells are involved with the immune response?

B Lymphocytes T Lymphocytes

Macrophages Neutrophils

TYPES OF IMMUNITY

1. Natural (Actively-Acquired Immunity)

a. Immunity to a specific microorganism due to having had the disease

b. Gives life-long immunity for that particular microorganism as Memory Cells are produced

c. Examples: Measles, Mumps, Chickenpox

2. Artificially Acquired Immunity

a. Killed or attenuated (weakened) antigen tricks the body into producing antibodies

b. Believed to provide life-time immunity as Memory Cells are also produced

c. Examples: Measles, Mumps, Chickenpox, Pertussis

3. Passive Immunity

a. Uses antibodies produced by another organism – human or animal

b. Immunity is temporaryc. No memory cells are produced

d. Types:1. Artificially-Acquired Passive Immunity

a. Antitoxin

1. A substance formed after exposure to a Toxin in same way the body produces antibodies

2. Examples: Tetanus, Antivenom, botulism

b. Gamma Globulin (Immune Globulin)

1. Human immune serum used for exposure to Hepatitis A

2. No Antigen is used, so no Memory Cell is produced

2. Naturally-Acquired Passive Immunity

--- Antibodies received by the Newborn from it’s mother

Any time a nurse gives a patient an immunizing agent against a specific disease, what does he/she need to be concerned about?

Called?

-- Severe allergic reactions can develop in some sensitive individuals

Anaphylaxis

TERMINOLOGYTERMINOLOGY

Disinfection

-- Attempt to kill pathogenic microorganism either through physical or chemical means applied directly

Disinfestation

--Destruction of insects, rodents, or other animal forms, which may transmit disease.

Endemic -- a disease of low morbidity that is constantly present in a human community, but clinically recognizable in only a few

Pierce County

Epidemic -- a disease attacking many people in a region at the same time

Pandemic -- worldwide epidemic disease

Incident --number of new cases of a specific disease occurring during a certain period

Incubation period

--the time required for the development of the disease

November 2005October 2005

30 new cases

8 new cases

Prevalence

--total number of cases of a specific disease in a given population at a certain time. West Nile Virus – Washington

State (2005)

WNV-Positive Humans: 0

WNV-Positive Horses: 1

WNV-Positive Birds: 1

WNV-Positive Mosquito Pools: 2

In State Acquired Cases

Suspect -- questionable, debatable origin of a disease

Gaetan Dugas

Bactericidal

Bacteriostatic

-- able to kill bacteria

-- arresting the growth or multiplication of bacteria

Drainage

1. Sanguineous

2. 2. SerosanguineousSerosanguineous

3. Serous

4. Purulent

-- bright red: indicates active bleeding

-- pale, red, watery: mixture of serous and sanguineous

-- clear, watery plasma

-- thick, yellow, green, tan, or brown

INFECTIONS

AcuteChronicPrimarySecondaryLocalGeneralized Systemic

FocalLatentSpecificMixed

-- the use of appropriate barrier when anticipating contact wit blood or other body fluids of any patient

STANDARD (UNIVERSAL) PRECAUTIONS

Reasons for the increase in infectious diseases: more susceptible people neglect in getting immunizations Increase in resistant microorganisms Increase in the number of pre-schools and

day care children Not all states require that all students

receive certain vaccinations Increase in number of ill or susceptible

people entering into the country

TYPES OF ISOLATION

Disease-specific isolations-- to prevent the spread of a particular

disease

Category Isolation

A. Strict Isolation

1. Most restrictive

2. Highly contagious diseases

3. Chickenpox; diphtheria; viral hemorrhagic fevers; varicella zoster (shingles)

B . Contact Isolation

1. Pathogens can be spread by touching

2. Wound infections with virulent or multiple drug resistant; rabies; scabies

Itch mite

MRSA

C. Respiratory Isolation

1. Transmitted by droplet or airborne

2. Measles; meningitis; mumps; drug resistant TB; Severe Acute Respiratory Syndrome (SARS)

D. Enteric Precautions

1. Transmitted by anal-oral route2. Hepatitis A

E. AFB Isolation

1. Acid-Fast bacillus

2. Tuberculosis (requires room with special ventilation)

Reverse or Protective Isolation

A. Prevents Infection in highly susceptible persons

B. CDC recommends conscientious medical asepsis; such as HANDWASHING

Role of Infectious Control Nurse

A. Detection of Nosocomial infection

C. Reporting

B. Recording

-- Most common nosocomial infections

1. Staphylococcus aureus

2. Pseudomonas aeruginosa

3. Escherichia coli

-- Infection control committee

-- Pierce County Health Department

-- State Health Department in Olympia

-- CDC – Atlanta Georgia-- Surgeon General’s Office

-- WHO

http://www.cdc.gov/ncidod/dhqp/pdf/guidelines/Isolation2007.pdf

Guideline for Isolation Precautions Preventing Transmission of Infectious Agents in

Healthcare Settings 2007