Principles of Asepsis Chapter 19 Medical Assisting PowerPoint® presentation to accompany: Medical Assisting Third Edition Booth, Whicker, Wyman, Pugh, Thompson

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.

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.

Introduction Our bodies are amazing structures that defend us against infections under normal circumstances You will learn about: Disease-causing microorganisms How the body fights disease Ways infections occur Antibiotic-resistant organisms Importance of patient education on the proper use of antibiotics

History of Infectious Disease Prevention Throughout history people have attempted to discover Causes of infection How to prevent infections How to treat infections

History of Infectious Disease Prevention (cont.) Scientist Contribution Edward 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

History of Infectious Disease Prevention (cont.) 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

History of Infectious Disease Prevention (cont.) Scientist Contribution Robert 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

History of Infectious Disease Prevention (cont.) Remarkable advances in the past century Threat of infection still present New infectious diseases AIDS Ebola Resistant diseases MRSA VRSA Multidrug-resistant TB

Right! 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. Right!

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

Microorganisms and Disease (cont.) Classification Characteristics Example Disease Prions * Infectious particle made of protein No nucleic acid Reproduction unknown Pr P CJD BSE Mad cow disease * Experts disagree as to whether prions are directly responsible for disease or merely aid an unknown agent in causing disease.

Microorganisms and Disease (cont.) 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

Microorganisms and Disease (cont.) 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

Correct! Apply Your Knowledge 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!

Infectious Diseases Knowing signs and symptoms of common infectious diseases can help protect against exposure

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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) Hepatitis Viral infection of liver Spread through blood or fecal-oral route HIV/AIDS Human immunodeficiency virus Acquired immune deficiency syndrome

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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.

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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.

Infectious Diseases (cont.) 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.

Infectious Diseases (cont.) 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.

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) Tetanus Acute infectious bacterial disease following a contaminated puncture wound Incubation – 3 to 21 days Late symptoms – lockjaw, paralysis No isolation needed, but reportable

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Infectious Diseases (cont.) 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

Excellent! Apply Your Knowledge How can the spread of many infectious diseases can be limited or prevented? 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 Excellent!

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

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)

Drug-Resistant Microorganisms (cont.) 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

Drug-Resistant Microorganisms (cont.) 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

Apply Your Knowledge 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!

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

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

Apply Your Knowledge SUPER! What are the four stages of illness? 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 SUPER!

The Body’s Defenses First lines of defense 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

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

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

The Body’s Defenses: Nonspecific Inflammation Signs Redness Localized heat Swelling Pain Purpose Summon immunologic agents to site Begin tissue repair Destroy invading microorganisms Steps Initial constriction, then dilation of blood vessels, causing redness and heat Fluid leakage from local vessels  swelling Scar tissue formation Chronic inflammation damages tissues and causes permanent loss of function

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

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

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

Impressive! Apply Your Knowledge 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!

Click for 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

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 Click for Cycle of Infection

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. Click for Cycle of Infection

Cycle of Infection (cont.) 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

Cycle of Infection (cont.) 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 Pathogen factors Number and concentration Virulence Point of entry Click for Cycle of Infection

Cycle of Infection (cont.) Back

Cycle of Infection (cont.) Environmental factors Dense populations Animals Unpasteurized milk Insects Economic and political factors Availability of transportation Population growth rates Sexual behavior

Nice Job! Apply Your Knowledge What are fomites? ANSWER: Fomites are inanimate objects such as clothing, water, and food that serve as a means of transportation for microorganisms. Nice Job!

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

Medical Assistant In Summary As knowledge about causes of infection have increased, principles and practices of asepsis have developed. Medical Assistant Must learn how pathogens cause disease, how disease is transmitted, and how to prevent the spread of infection. Use this knowledge to educate patients about remaining healthy and decreasing the risk of contracting disease.

End of Chapter End of Chapter 19 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