Immunity and Infection

1. Immunity and Infection Chapter 17

2. The Chain of Infection • Links in the Chain • Transmitted through a chain (six links) • Pathogen - disease causing microorganism • Reservoir - natural environment of the pathogen: Person, animal, or environmental component • Portal of Exit • Means of transmission • Direct transmission • Indirect transmission • Vectors – carrier of the pathogen from one host to another • Portal of entry • Penetration of the skin • Inhalation through mouth or nose • Ingestion • New host • Breaking the Chain Immunity and infection

4. Body’s Defense System • Physical and Chemical barriers • Skin, mucous membranes, respiratory tract • The Immune System • Immunological Defenders • Neutrophils • Macrophages – “big eaters” • Natural killer cells • Dendritic cells – eat pathogens and activate lymphocytes • Lymphocytes • T-cells • Helper, Killer, and Suppressor • B-cells • Antibodies • Memory T and B cells

6. The Inflammatory Response • Histamine. • Dilation of blood vessels, heat, redness, and swelling. • The immune response • Phase 1 – Dendritic cells are drawn to the site • Phase 2 – Helper T cells multiply • Production of Killer T and B cells • Cytokines – chemical messengers • Phase 3 – Killer T cells strike • Cell-mediated immune • Antibody-mediated immune response • Phase 4 – Last Phase – • Suppressor T-cells • Slow down activity

8. Immunity • An infected person will never get the same illness again. • Lymphocytes create amplification of the immune response are reserved by memory T and B cells • Symptoms and contagion • Incubation – viruses are multiplying in the body or when bacteria are actively multiplying • Will not feel symptoms until the second or third phase of the immune response cycle • Prodromal period – the infected host has acquired immunity

9. Immunization • The process of ‘priming’ the body to remember an encounter with a specific antigen. • Types of vaccines • VACCINE- Introduction of a killed or weakened pathogen to stimulate the body to produce antibodies. • ACTIVE IMMUNITY - person produces his or her own antibodies to the microorganism. • PASSIVE IMMUNITY- Injection of antibodies produced by other human beings or animals. • ACQUIRED IMMUNITY-The ability of a memory lymphocytes to remember a previous infection. (chicken pox).

10. Immunization Issues • Vaccine shortages in the U.S. • Vaccine safety

11. Allergy: The Body’s Defense System Gone Haywire • The Body’s Defense System Gone Haywire • Allergies • Allergens • Pollen, Animal Dander, Dust mites and cockroaches, Molds, Food, Insects • The Allergic response • Immunoglobulin (IgE) • Anaphylaxis

13. Dealing With Allergies • Avoidance • Medication • Immunotherapy “allergy shots

15. Pathogens and Disease • Bacterium – Microscopic single celled organism • Pneumonia • Meningitis • Strep Throat and other streptococcal infections • Toxic shock and other staphylococcal • Tuberculosis • Tickborne infections • Ulcers • Other Bacterial infections • Tetanus • Pertussis • Urinary tract infections

16. Antibiotic Treatment • Actions of Antibiotics • Antibiotic resistance • Proper antibiotics usage • Don’t take an antibiotic every time you are sick • Use antibiotics as directed • Never take an antibiotic without an prescription

17. Type of Pathogens • Viruses – (parasites – take what they need) • Most common contagious disease • Common Cold • Influenza • Measles, Mumps and Rubella • Chickenpox, Cold Sores, and other herpes-virus infections • Varicella-zoster virus • Herpes simplex virus (HSV) types 1 and 2 • Epstein-Barr virus (EBV) • Viral encephalitis • Viral hepatitis • Poliomyelitis • Rabies • Human papillomavirus (HPV) • Treatment

19. Types of Pathogens • Fungi – • Primitive plant – Yeast infections, athletes foot, jock itch, and ringworm • Candida albicans • Protozoan – • Microscopic single-celled animal – Malaria, African sleeping sickness, Giardiasis, Tricomonias, Trypanosomiasis, and Amoebic dysentary. • Parasitic worm – • Largest organism that can enter the body – Tapeworm, Hookworm, and Pinworm. • Prions – • Fetal degeneration disorders of the CNS, linked to “proteinaceous infectious particles. • Lack DNA and RNA • Transmissible spongiform encephalopathies (TSEs) • Spongelike holes in the brain • Creutzfeldt-Jakob disease – Human • Bovine spongiform encephalopathy (BSE) or mad cow disease

20. Emerging Infectious Diseases • Selected Infections of concern • West Nile virus • Severe acute respiratory syndrome (SARS) • Rotavirus • Escherichia coli 0157:H7 • Hantavirus • Ebola

21. Factors Contributing to Emerging Infections • Drug Resistance • Poverty • Breakdown of public health measures • Environmental changes • Travel and Commerce • Mass food production and distribution • Human behaviors • Bioterrorism

22. Other Immune Disorders: Cancer and Autoimmune Diseases • If the immune system breaks down • Getting older • HIV infection • Chemotherapy • Autoimmune diseases • Rheumatoid arthritis • Systemic lupus erythmatosus

23. Support Your Immune System How to support your immune system General guidelines Plenty of clean water Avoid contact with vermin Practice safe sex Do not use Injectable drugs Vaccinations Controlling Stress • Balanced diet • Enough sleep • Exercise • Don’t smoke • Moderation of alcohol • Wash your hands • Avoid contact with contagious people

24. Chapter 17 Immunity and Infection