19-1 © 2009 The McGraw-Hill Companies, Inc. All rights reserved Principles of Asepsis PowerPoint® presentation to accompany: Medical Assisting Third Edition.

19-1

© 2009 The McGraw-Hill Companies, Inc. All rights reserved

Principles of AsepsisPrinciples of AsepsisPowerPoint® presentation to accompany:

Medical AssistingThird Edition

Booth, Whicker, Wyman, Pugh, Thompson

19-2


Learning Outcomes

19.1 Explain the historical background of infectious disease prevention.

19.2 Identify the types of microorganisms that cause disease.

19.3 List some infectious diseases, and identify their signs and symptoms.

19.4 Discuss the importance of preventing antibiotic resistance in a health-care setting.

19.5 Describe ways you can help prevent antibiotic resistance in health-care settings.

19-3


Learning Outcomes (cont.)

19.6 Explain the disease process.

19.7 Explain how the body’s defenses protect against infection.

19.8 Describe the cycle of infection.

19.9 Identify and describe the various methods of disease transmission.

19.10 Explain how you can help break the cycle of infection.

19-4


Introduction

Antibiotic-resistant organisms

Importance of patient education on the proper use of antibiotics

You will learn about: Disease-causing

microorganisms How the body fights disease Ways infections occur

Our bodies are amazing structures that defend us against infections undernormal circumstances

19-5


History of Infectious Disease Prevention Throughout history

people have attempted to discover

Causes of infection

How to prevent infections

How to treat infections

19-6


History of Infectious Disease Prevention (cont.)

Scientist ContributionEdward Jenner (1749–1823) Developed first effective

vaccine Used cowpox to vaccinate against small pox

Ignaz Semmelweis (1818–1865) and Oliver Wendell Holmes (1809–1894)

Promoted handwashing as a means of reducing the spread of Puerperal fever to women in childbirth

19-7


Scientist Contribution

Louis Pasteur (1822–1895) Helped develop the germ theory of infectious disease stating that disease is caused by microorganisms

Joseph Lister (1827–1912) Helped develop germ theory Introduced aseptic

techniques through the use of antiseptics on wounds, surgical sites, and surgical instruments


19-8


Scientist ContributionRobert Koch (1843–1910) Developed a set of proofs,

known as Koch’s Postulates, claiming that microbes cause disease

Sir Alexander Fleming (1881–1955)

Discovered penicillin


19-9


Remarkable advances in the past century Threat of infection still present

New infectious diseases AIDS Ebola

Resistant diseases MRSA VRSA Multidrug-resistant TB


19-10


Apply Your Knowledge

Why is the threat of infection still present even though great advances have been made in controlling infections over the past century?

ANSWER: The threat of infection is still present because of new diseases and diseases that have become resistant to treatments.

19-11


Microorganisms and Disease Microorganisms live all around us

Pathogens Microorganisms capable of causing disease Evade host defenses

People avoid infections most of the time Many microorganisms are beneficial or harmless Normal defenses resist infection Conditions are not favorable for pathogens to grow and

be transmitted

19-12


Microorganisms and Disease (cont.)

Classification

Characteristics Example

Disease

Prions * Infectious particle made of protein

No nucleic acid Reproduction

unknown

Pr P CJD

BSEMad cow disease

* Experts disagree as to whether prions are directly responsible for disease or merely aid an unknown agent in causing disease.

19-13


Classification

Characteristics

Example

Disease

Viruses DNA or RNA surrounded by protein coat

Reproduced in living cells

Very small

Varicella-zoster virus

Chickenpox

Bacteria Single-celled Reproduce quickly Mostly asexual reproduction

Vibrio cholerae

Cholera


19-14


Classification

Characteristics Example Disease

Protozoans Single-celled Reproduction mostly asexual

Entamoeba histolytica

Amebic dysentery

Fungi Multicellular Reproduction is sexual and asexual

Candida albicans

Candidiasis

Helminths Multicellular parasitic Contain specialized organs Sexual reproduction

Enterobius vermicularis

Pinworms


19-15



In many cases, we avoid contracting infections when exposed to microorganisms. What are the reasons for this?

ANSWER: This is because:

many microorganism are beneficial or harmless

we have normal defenses to resist infection

conditions are not favorable for the pathogen to grow and be transmitted.

Correct!

19-16


Infectious Diseases Knowing signs and

symptoms of common infectious diseases can help protect against exposure

19-17


Infectious Diseases (cont.)

Chickenpox (Varicella)

Contagious viral infection Incubation period of 7 to 21 days Itchy rash fluid-filled blisters Slight fever, headache, general malaise Spread by direct, indirect, droplet, or airborne transmission Isolate until all blisters have scabbed over 1996 – live vaccine approved

19-18



Common cold

Viral infections of upper respiratory tract No isolation needed Commonsense precautions to prevent

spread Use tissues when coughing or sneezing Wash hands frequently Use disposable dishware, if possible

Incubation – 2 to 3 days

19-19



Croup Most often caused by a virus Characterized by a harsh, barking cough,

difficulty breathing, hoarseness, and low-grade fever

Most common in infants and young children

Symptoms lessened by humidification of air, rest, and clear fluids

Commonsense precautions to prevent spread

19-20



Diphtheria Bacterial infection of nose, throat, and larynx

Symptoms: pain, fever, respiratory obstruction

Incubation – 2 to 5 days Isolation required Antibiotic therapy (fatal if untreated) Immunization available

19-21



Epstein-Barr Virus

Common human virus 95% of adults have had virus

35 – 50% of teens develop mononucleosis

Symptoms – fever, sore throat, swollen lymph nodes

Virus remains dormant for life Occasionally reactivates as tumors

19-22



Haemophilus Influenzae Type B

Bacterial infections in infants and young children

Spread – direct, indirect, and droplet transmission

Incubation – 3 days Upper respiratory symptoms, fever,

drowsiness, body aches, diminished appetite

Monitor closely – bacterial meningitis

19-23



Hepatitis Viral infection of liver Spread through blood or fecal-oral

route

HIV/AIDS Human immunodeficiency virus Acquired immune deficiency syndrome

19-24



Influenza (Flu)

Symptoms – fever, chills, headaches, body aches, upper respiratory congestion

Isolation and commonsense precautions Vaccines

Live, attenuated virus – nasal spray Inactivated virus – IM injection

Annual vaccination People at risk for complications

People older than 50 years old People in close contact with persons at risk for

complications

19-25



Measles (Rubeola)

Infectious viral disease Spread by droplets or direct transmission Initial symptom of fever develops 8 to 13

days after exposure, followed by a characteristic itchy rash 14 days after exposure

Isolation for 7 days after rash appears Keep children under 3 years old away from

anyone with the disease Reportable to state or county health dept.

19-26



Meningitis Inflammation and infection of protective coverings of brain and spinal cord and the fluids around them

Viral – milder form Clears in 1 to 2 weeks without treatment Aseptic meningitis

19-27



Meningitis Bacterial – serious, life-threatening, requiring immediate treatment Vaccination available for people in high-risk

groups Symptoms – red, blotchy rash, confusion,

delirium, light sensitivity, headache, fever and chills, nausea and vomiting, sleepiness, stiff neck

May spread through exchange of respiratory and throat secretions

Reportable to state or county health dept.

19-28



Mumps Viral infection Primarily affects salivary glands

Incubation – 2 to 3 weeks Pain related to inflammation of parotid

gland and fever Isolate until glandular swelling stops Reportable to state or county health

dept.

19-29



Pertussis (Whooping Cough)

Highly contagious bacterial infection of respiratory tract

Symptoms – fever, sneezing, runny nose, quick short coughs, characteristic “whoop” during inhaled breath following coughing fit

Isolate for 3 weeks following onset of spasmodic coughs

Reportable to state or county health dept.

19-30



Roseola Rose-colored rash possibly caused by human herpes virus

Infants and young children Incubation 5 to 15 days Symptoms – sudden, high fever; sore throat;

swollen lymph nodes; rash

Rubella (German Measles)

Highly contagious viral disease Direct or droplet transmission Incubation 16 to 18 days Symptoms – fever and itchy rash Vaccination available Reportable

19-31



Streptococcal pharyngitis (strep throat)

Bacterial infection of throat Sore throat, swelling of pharyngeal mucosa, fever, headache, nausea, abdominal pain Treat with antibiotics

Scarlet fever Bacteria becomes systemic Characteristic “strawberry rash” Incubation 7 to 10 days Isolate 7 days

19-32



Streptococcal pharyngitis(cont.)

Rheumatic fever Occurs after apparent recovery from strep throat Autoimmune disorder – antibodies to

streptococci cross-react with heart tissues Symptoms – carditis, ECG changes, joint pain

and inflammation, fever

Acute post-streptococcal glomerulonephritis Inflammation of glomerulus of the kidney

resulting in inadequate filtering of the blood Symptoms – swelling of hands and feet,

decreased urine output, hypertension, protein in urine

19-33



Tetanus Acute infectious bacterial disease following a contaminated puncture wound

Incubation – 3 to 21 days Late symptoms – lockjaw, paralysis No isolation needed, but reportable

19-34



Tuberculosis Infectious bacterial disease affecting mainly lungs Symptoms – night sweats, productive cough, fever, chills, fatigue, unexplained weight loss, diminished appetite, bloody sputum

Incidence – higher in urban centers

Transmission Mycobacterium tuberculosis Droplet

19-35



Tuberculosis (cont.)

Increasing resistance to TB Early diagnosis, prompt treatment Compliance with treatment regimen

Preventing TB Vaccination – BCG (not used in the U.S.) Causes false-positive with TB skin test

19-36



Tuberculosis (cont.)

Treating TB Mantoux TB test

Positive test = Induration – skin turns red and becomes raised and hard Positive result from immunization or exposure to TB bacteria

Treatment based on area affected and type of TB involved Patients must complete entire course of treatment – 12 to 18 months on medication Isolation

19-37



ANSWER: The spread of many infectious diseases can be limited or prevented by using common sense precautions: Using tissues when coughing or sneezing Washing hands frequently Using disposable dishware

How can the spread of many infectious diseases can be limited or prevented?

Excellent!

19-38


Drug-Resistant Microorganisms MRSA – methicillin/oxacillin-resistant S. aureus

VRE – vancomycin-resistant enterococci

VISA – vancomycin-intermediate S. aureus

VRSA – vancomycin-resistant S. aureus

ESBLS – extended-spectrum beta-lactamases

PRSP – penicillin-resistant Streptococcus pneumoniae

19-39


Drug-Resistant Microorganisms (cont.)

MRSA and VRE Most common in non-hospital health-care facilities

Community-associated MRSA Increasing in incidence

PRSP Common in patients seeking care in physicians’ offices

and clinics (pediatrics)

19-40



Risk factors for development of infections by drug-resistant organisms Advanced age Invasive procedures Prior use of antibiotics Repeated contact with health-care system Severity of illness Underlying diseases of conditions

19-41



Preventing antibiotic resistance Four strategies to reduce incidence of antibiotic-

resistant microorganisms Prevent infection Diagnose and treat infection

appropriately Use antibiotics carefully Prevent transmission of

infections

19-42



What strategies reduce the incidence of antibiotic-resistant microorganisms?

ANSWER: Strategies to reduce the incidence of antibiotic-resistant microorganisms include:

Prevent infections

Diagnose and treat infections appropriately

Use antibiotics carefully

Prevent transmission

Good Job!

19-43


Disease Process Begins with

microorganisms finding host

Grows with specific requirements

Proper temperature

pH

Moisture level

Virulence – microorganism’s disease-producing power

Damage is caused by:

Depleting nutrients

Reproducing themselves

Making body cells the target of body’s own defenses

Producing toxins

19-44


Disease Process (cont.)

Once exposed to a pathogen, the body goes through 4 stages of illness:

Incubation – begins at first exposure; ends when first symptom appears

Prodromal – begins at first onset of symptoms; generally short

Invasion – numbers of organisms are greatest; symptoms are most pronounced

Convalescent – patient regains normal health status

19-45



ANSWER: The four stages of illness are: Incubation – begins at first exposure; ends when first symptom appears Prodromal – begins at first onset of symptoms; generally short Invasion – numbers of organisms are greatest; symptoms are most pronounced Convalescent – patient regains normal health status

What are the four stages of illness?

19-46


The Body’s Defenses Immunity – condition

of being resistant to pathogens and the disease they cause

First lines of defense Skin Sweat glands Mucous membranes Cilia Lacrimal glands Saliva Hydrochloric acid Lysozyme

19-47


The Body’s Defenses (cont.)

Resident normal flora – microorganisms found in the body Provide a barrier against pathogens

Normally live in balance

Become pathogenic when host’s defenses are compromised

Opportunistic infections Infections occurring when a host’s resistance is low

19-48


The Body’s Defenses (cont.)

Immune system includes nonspecific defenses Mechanisms to protect against pathogens in

general Includes

Nonspecific defenses Humoral defenses Cell-mediated defenses

19-49


The Body’s Defenses: Nonspecific Inflammation

Signs Redness Localized heat Swelling Pain

Purpose Summon immunologic

agents to site Begin tissue repair Destroy invading

microorganisms

Steps1. Initial constriction, then

dilation of blood vessels, causing redness and heat

2. Fluid leakage from local vessels swelling

3. Scar tissue formation

Chronic inflammation damages tissues and causes permanent loss of function

19-50


The Body’s Defenses: Nonspecific (cont.)

Phagocytosis White blood cells (phagocytes)

engulf and digest pathogens Three types

Neutrophils – found in pus Monocytes – formed in bone marrow and become Macrophages when they migrate to specific tissues

Found in lymph nodes, liver, spleen, lungs, bone marrow, and connective tissue

Deliver antigens (foreign substances) to lymphocytes

19-51


The Body’s Defenses: Humoral Immunity Lymphocytes – B cells and T cells

T cells activate B cells to produce antibodies to neutralize an antigen

Memory B cells respond quickly to produce antibodies in later invasions

Specific antibodies are produced in response to specific antigens

Antibodies attract phagocytes, which destroy antigens

19-52


Types of immunity Active – body produces own antibodies

Natural active Artificial active

Passive – antibodies that are produced outside body enter the body Natural passive Artificial passive

Complement Proteins activated by antibodies Helps white blood cells destroy pathogens

The Body’s Defenses: Humoral Immunity (cont.)

19-53


The Body’s Defenses: Cell-Mediated Immunity

T cells attack invading pathogen directly Helper T cells

Activate

Killer T cells Bind with antigen and kill it

Suppressor T cells Slow down or stop attack after antigen is destroyed

Memory T cells Respond quickly to another attack by same antigen

19-54



What is the difference between active and passive immunity?

ANSWER: Active immunity is long-term immunity in which the body produces its own antibodies.

Passive immunity results when antibodies produced outside the body enter the body.

Both can be natural or artificial.

Impressive!

19-55


Cycle of Infection A reservoir host – animal, insect, or human

body capable of sustaining pathogen growth Carrier – unaware of presence of pathogen Subclinical case – unnoticeable infection Endogenous infection – normally harmless

microorganisms become pathogenic Exogenous infection – pathogen introduced

into the body

Click for Cycle of Infection

19-56


Cycle of Infection (cont.)

Means of exit – how the pathogen leaves the host Nose, mouth, eyes, or ears Feces or urine Semen, vaginal fluid, or other

reproductive discharge Blood or blood products


19-57


Cycle of Infection (cont.) Means of transportation – how a pathogen spreads

to a host Airborne Blood-borne During pregnancy or birth Foodborne Vector-borne

Living organism that carries microorganisms to another person

Touching Direct Indirect through

fomites Inanimate reservoir

of pathogens Drinking glass,

door knob, etc.


19-58


Means of entrance Enter through any cavity lined

with mucous membrane Mouth, nose, vagina, rectum Ears, eyes, intestinal tract, urinary

tract, reproductive tract, breaks in the skin


Click for Cycle

of Infection

19-59



Pathogen factors Number and

concentration

Virulence

Point of entry

Susceptible host Individual with little or no

immunity to infection by a pathogen

Host factors influencing susceptibility Age Genetic predisposition Nutritional status Other disease processes Stress levels Hygiene habits General health


19-60



Back

19-61



Environmental factors Dense populations Animals

Unpasteurized milk Insects Economic and political factors Availability of transportation Population growth rates Sexual behavior

19-62



ANSWER: Fomites are inanimate objects such as clothing, water, and food that serve as a means of transportation for microorganisms.

What are fomites?

Nice Job!

19-63


Breaking the Cycle Asepsis – condition in which

pathogens are absent or controlled Maintain strict housekeeping

standards Adhere to government

guidelines to protect against disease

Educate patients in hygiene, health promotion, and disease prevention

19-64


In Summary

Medical Assistant

Must learn how pathogens cause disease, how disease is transmitted, and how to prevent the spread of infection.

As knowledge about causes of infection have increased, principles and practices of asepsis have developed.

Use this knowledge to educate patients about remaining healthy and decreasing the risk of contracting disease.

19-65


End of Chapter

In today's world, new infections and

diseases can spread across the country

and even across the world in a matter of

days, or even hours, making early

detection critical.

~ John Linder

U.S. Representative, Georgia

19-1 © 2009 The McGraw-Hill Companies, Inc. All rights reserved Principles of Asepsis PowerPoint® presentation to accompany: Medical Assisting Third Edition.

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