An Invitation to Health Chapter 15: Avoiding Infectious Diseases Prepared by: Andrew Owusu Ph.D.
Chapter 15 Objectives Explain how different agents of infection spread disease. Describe how your body protects itself from infectious disease. List ways to protect yourself from catching a cold or the flu and ways to feel better if you do catch one. Name and describe some common infectious diseases. Explain the dangers of overuse of misuse of antibiotics. Name the infectious diseases for which you are most at risk, and list your strategies for avoiding them.
How Do You Catch An Infection? Animals and Insects Water People Food
Pathogens Virus Bacteria Fungi Protozoa Rickettsia How do infections occur? Body has normal resistance to most pathogens
4 Ways to Enter the Body Direct Fluid to Fluid Indirect Infected Surface Airborne Water Vapor Vector-borne Non-human Carrier
For Infection to Occur… • Pathogen • Quantity • Vulnerability • Entry Site/Mode
The Process of Infection 7. Termination 6. Recovery or Relapse 5. Clinical Stage 4. Prodormal Period 3. Incubation Period 2. Infection 1. Exposure
How Your Body Protects Itself • Tears, sweat, skin oils, saliva, mucus, and cilia. • Lymphatic System Organs and Components: • Spleen, thymus gland, lymph nodes, and lymph vessels. • Lymphocytes (white blood cells)
The Human Lymphatic System and Its Functions Tonsils • Defense against bacteria and other foreign agents Thymus gland • Site where certain white blood cells acquire means to chemically recognize specific foreign invaders Right lymphatic duct • Drains right upper portion of body Thoracic duct • Drains most of body Spleen • Site where antibodies are manufactured; disposal site for old red blood cells and foreign debris; site of red blood cell formation in the embryo Lymph nodes • Store protective cells and destroy pathogens Some of the lymph vessels • Return excess fluid and reclaimable solutes to the blood Some of the lymph nodes • Filter bacteria and many other agents of disease from lymph Bone marrow • Marrow in some bones are production sites for infection-fighting blood cells (as well as red blood cells and platelets) Fig. 14-1, p. 395
The Immune Response Infected body cell T T Pathogen Antigen Memory T cells remain in the body to kick-start the fight if the pathogen returns. T Macrophage T T T Antibody NK B B Natural killer cell Fig. 15-2, p. 440
Immune DisordersAllergies • Hypersensitivity to a substance in our environment or diet. • Symptoms • Itching, nasal congestion, eye irritation, coughing, wheezing, hives, vomiting, and diarrhea, and even sudden life-threatening collapse. • Treatments • Non-sedating oral medications, nasal sprays, and immunology.
Immune DisordersAutoimmune Disorders • When the immune system declares war on the cells, tissues, or organs it normally protects. • Types • Graves disease, systematic lupus, scleroderma, rheumatoid arthritis and multiple sclerosis. • Causes • Genetics, drugs, chemicals, bacteria and viruses. • Treatments • Medications. • New diagnostic tests and treatments are on the horizon.
Recommendations for Adult Immunizations Tetanus, Diphtheria Hepatitis B Hepatitis A Measles, Mumps and Rubella Varicella (Chickenpox) Meningococcal Disease Influenza Pneumococcal Disease
Who Is At Highest Risk of Infectious Disease? Children & Their Families The Elderly The Chronically Ill Smokers & Those With Respiratory Problems Individuals Working With Sick Individuals Residing In Poorly Ventilated Buildings
Common Infectious Diseases • Common Cold • Influenza • Meningitis • Hepatitis • Mononucleosis • Chronic Fatigue Syndrome (CFS) • Pneumonia • Tuberculosis • Group A and Group B Strep Infection • Toxic Shock Syndrome • Insect- and Animal-Borne Infections • New Infectious Treats
Common Cold Facts • There are 200 distinct cold viruses. • Americans come down with 1 billion colds annually. • The common cold results in ~20 million lost work days and 22 million days of absence from school. Spring, Summer and Early Fall Colds • Rhinoviruses causing symptoms above the neck • Stuffy nose, headache and runny nose. Winter Colds • Adenoviruses, parainfluenza viruses, coronaviruses and influenza viruses. • These viruses are more likely to get into the bronchi and trachea and cause more fever and bronchitis.
Treatments for the Common Cold Limit Aspirin and Acetaminophen (Tylenol) • Suppresses important antibodies and increases symptoms. • Reye’s syndrome Ibuprofen Antihistamines • Watch for drowsiness • Individuals with high blood pressure, diabetes, heart disease, or thyroid disorders should limit products containing pseudoephedrine. Limit Multisymptom Medications Alternative Remedies • ? Vitamin C, Echinacea, zinc lozenges
Individuals Who Should Get Flu Shots • Individuals aged 65 years and older. • Residents in long term care facilities. • Individuals aged 2 to 64 years with chronic health conditions. • Children aged 6 to 23 months. • Pregnant women. • Health-care personnel • Household contacts and caregivers.
When someone with active tuberculosis exhales, coughs, or sneezes, tuberculosis is expelled in tiny airborne droplets that others may inhale. How Tuberculosis Spreads The TB bacteria lodge mainly in the lungs, where they slowly multiply, creating patches, then cavities, in the lungs. Other parts of the lung are affected, including bronchi and the lining of the lung. If untreated, TB can eventually spread to and damage the brain, bone, eyes, liver and kidneys, spine, and skin. Fig. 14-4, p. 405