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Immunity and Infection Chapter 13 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 • Transmission – Direct transmission – Indirect transmission • Portal of entry – Penetration of the skin – Inhalation – Ingestion • New host – Breaking the Chain Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 2 Body’s Defense System • Physical and Chemical barriers – Skin, mucous membranes, respiratory tract • The Immune System – Immunological Defenders • • • • • Chapter 13 Neutrophils Macrophages Natural killer cells Dendritic cells Lymphocytes – T-cells » Helper, Killer, and Suppressor – B-cells » Antibodies – Memory T and B cells © 2008 McGraw-Hill Companies. All Rights Reserved. 3 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 • Anti-body mediated immune response – Phase 4 – Last Phase – • Suppressor T-cells • Slow down activity Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 4 The Immune Response Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 5 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 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 6 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). – PASSIVE IMMUNITY- Injection of antibodies produced by other human beings or animals. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 7 Allergy: The Body’s Defense System Gone Haywire – Allergies – Allergens • Pollen, Dander, Dust mites, Molds, Food, Insects – The Allergic response • Immunoglobulin (IgE) • Anaphylaxis – Dealing with Allergies • Avoidance • Medication • Immunotherapy Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 8 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 9 The Troublemakers: Pathogens and Disease • Bacteria – Microscopic single celled organism – – – – – – – – Pneumonia Meningitis Strep Throat and other streptococcal infections Toxic shock and other staphylococcal Tuberculosis Lyme Disease and other tickborne infections Ulcers Other Bacterial infections • Tetanus • Pertussis • Urinary tract infections Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 10 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 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 11 Pathogens • Viruses – (parasites – take what they need) – – – – Common Cold Influenza Measles, Mumps and Rubella Chickenpox, Cold Sores, and other herpes-virus infections • Herpes simplex virus (HSV) types 1 and 2 • Epstein-Barr virus (EBV) – Viral Hepatitis – Human Papillomavirus (HPV) • Treatment Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 12 Pathogens • Fungi – – Primitive plant – Yeast infections, athletes foot, and ringworm – Candida albicans • Protozoa – – 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 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 13 Emerging Infectious Diseases • Selected Infections of concern – – – – – – West Nile virus Severe acute respiratory syndrome (SARS) Rotavirus Escherichia coli Hantavirus Ebola Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 14 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 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 15 How to Support Your Immune System • How to support your immune system – Public Health – Taking care of yourself • Nutrition • Exercise • Rest • Moderation of Lifestyle • Controlling Stress Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 16 Sexual Transmitted Diseases The United States has the highest rate of Sexual Transmitted Diseases of any developed nation Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 17 The Major STDS (STD’s) • Seven different STDs pose major health threats – – – – – – – HIV/AIDS Hepatitis Syphilis Chlamydia Gonorrhea Herpes HPV Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 18 Acquired Immunodeficiency Syndrome (AIDS) • Leading cause of death in many parts of the world. – Worldwide, AIDS is the leading cause of death for people age 15-59 • Approximately 65 Million people around the world are infected with Human Immunodeficiency Virus (HIV). • More than 25 million have died worldwide • Human immunodeficiency virus (HIV) is the virus which causes AIDS. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 19 Approximate number of people living with HIV/AIDS in 2006 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 20 HIV Infection and AIDS • By 2004, an estimated 1,000,000 Americans were believed to be living with HIV, with an estimated annual incidence of 40,000 cases • Estimated 1.5 million Americans have died – 2006, researchers discovered a group of chimpanzees in Cameroon that carry SIVspc – 1930s Genetic evidence shows that SIV first spread to humans • What is HIV Infections? – HIV attacks and invades CD4 T-cells, monocytes and macrophages. – AIDS opens the possibility for a opportunistic infections. – Once initial symptoms resolve, the asymptomatic period may last from 2 to 20 years. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 21 Transmitting the Virus • HIV lives only within cells and body fluids. • 3 primary means of transmission are: (1)Specific kinds of sexual contact, (2) direct exposure to infected blood, and (3) HIV-infected women to her fetus. • • • • Sexual contact Direct contact with infected blood. Mother-to-Child transmission. Not through casual contact. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 22 Populations of Special Concern for HIV infection • Most common exposure has been sexual activity between men; injection drug use, and heterosexual contact. • African American men and women are vastly overrepresented among people newly diagnosed with AIDS. – See “HIV/AIDS Among African Americans and Latinos” Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 23 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 24 Symptoms of HIV Infection • Few days or weeks, half the people will develop (Flu like symptoms) – Fever, fatigue, rashes, headache, swollen lymph nodes, body aches, night sweats, sore throat, nausea and diarrhea. • Specialized test HIV RNA assay. • Pneumocystis Carinii pneumonia (protozoal infection). • Kaposis sarcoma. • Difficult to treat yeast infections in women • Tuberculosis Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 25 Diagnosing HIV Infection and AIDS • Most common is tests for the presence of antibodies to the virus. – HIV antibody test – ELISA (first test) if positive then the. – Western blot (second test) • IF HIV-positive then check the status of the CD4-t cells. • New diagnostic test – HIV Replication Capacity. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 26 Diagnosing HIV Infection and AIDS • Treatment (NO CURE). – Antiviral drugs. • Reverse transcriptase inhibitors. – Zidovudine (AZT). • Protease inhibitors. – Highly active antiretroviral therapy (HAART). – Structured intermittent therapy. • Fusion inhibitors – Enfuvirtide (Fuzeon) – Inhibit the fusion of viral and cell membranes – Post-Exposure prophylaxis. – Treatment for opportunistic infections. – HIV and Pregnancy Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 27 Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 28 Prevention • Make careful choices about sexual activity. • Do Not share drug needles. • Participate in an HIV educational program. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 29 Chlamydia Trachomatis • Most prevalent bacterial STD in the U.S. • Bacterial infection – Can cause sterility in men and women • WOMEN infects the cervix and to urethra, fallopian tubes & ovaries, PID, bladder infections. • MEN- Epididymitis, urethra to testes, urethritis, bladder infections, watery discharge. • Symptoms –ASYMPTOMATIC : Discharge, pain and burning while urinating, vaginal bleeding, painful intercourse, abdominal pain, nausea, fever, inflammation of rectum or cervix, swelling and pain in the testes. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 30 Chlamydia Trachomatis • Spread - vaginal and anal intercourse, from the birth canal to the fetus • Diagnosis - Examination of tissue samples or urine • Treatment - Both partners treated fully with antibiotics • Protection Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 31 Gonorrhea • 700,000 new cases every year in the U.S. • Bacterial infection - Can cause sterility, arthritis and heart problems – PID, can cause ectopic pregnancy, premature labor and still birth, arthritis, rashes • Symptoms – – Women - Asymptomatic - Frequent burning urination, menstrual irregularities, pelvic pain, discharge. – Males – thick yellow-white discharge, painful urination. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 32 Gonorrhea • Spread - Vaginal, anal and oral sex. • Diagnosis - Microscopic exam of discharge. • Treatment - Oral antibiotics People often have chlamydia at same time. • Protection Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 33 Pelvic Inflammatory Disease PID • Progressive infection that harms a women’s reproductive system. Can lead to sterility, ectopic pregnancy and chronic pain treated or not. • Caused by chlamydia and gonorrhea. • Symptoms - long and painful periods, discharge, spotting, low abdominal pain, fever, chills, nausea, vomiting, pain during intercourse. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 34 Pelvic Inflammatory Disease PID • Treatment - Antibiotics, bed rest, sexual abstinence and maybe surgery to remove scarring • Diagnosis - Pelvic Exam, cultures, laparoscopy • Protection Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 35 Human Papillomavirus Infection • More than 80% of sexually active individuals will have been infected with HPV by the age of 50. • Symptoms – Small bump on the skin or a large, warty growth – Cauliflower-like mass – May cause irritation and bleeding • How is it spread • Diagnosis – Appearance of the lesions – Women who are positive should have a Pap test very 12 months • Treatment – Removed by cryosurgery, electrocautery or laser surgery • Protection Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 36 Genital Herpes • 45 million have been diagnosed • Two forms - Herpes simples virus-1 and -2. • Type 1 is associated with cold sores and fever blisters. – 50-80% of U.S. adults have anitibodies to HSV-1 • Both are sexually transmitted. • Remains in the body for life. • Symptoms – 90% have no symptoms – Recurring rash, pain ulceration's. – Primary outbreak - pain and discomfort around infected area, itching, burning during urination. – 2-20 days after infection - may years before outbreak. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 37 Genital Herpes • Spread - Touching, sexual intimacy - including kissing, vaginal, oral and anal sex • Diagnosis - Examination of sores and culturing of fluid taken from sores • Treatment - No cure - symptoms are relieved by drugs • Protection - Refrain for sex during out break • HSV-1 and 2 can cause miscarriages or still births along with serious health issues of newborns Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 38 Hepatitis B Virus (HBV) • • • • • Can cause liver disease and death Preventable with vaccination. 750,000 total acquired sexually Transmission - Semen, saliva, blood and urine Symptoms - Extreme fatigue, headache, fever, hives, lack of appetite, nausea, vomiting, tenderness in lower abdomen • Diagnosis and Treatment – Blood Test – No cure – Prevention Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 39 Syphilis • Syphilis organism remains in the body for life and leads to disfigurement, neurological disorders, or death. • Effective antibiotics and condom use. • Symptoms – – Primary phase- 3 weeks - 90 days - painless sores and wet ulcers (chancre) and swollen glands. – Secondary Phase - 3-6 weeks - up to 2 years body rash, mild fever, fatigue, sore throat (Flu like symptoms), and hair loss. – Late phase (tertiary)- Damage to organs and nervous system. Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 40 Other STD’s • Trichomoniasis • Bacterial vaginosis (BV) • Pubic Lice • Scabies Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 41 What You Can Do • Education. • Diagnosis and Treatment – – – – – Get vaccinated Be alert for symptoms Get tested Inform your partners Get Treated • Prevention – Use a barrier defense. – Know your potential partner. • Ask. Are you ready to have sex? Chapter 13 © 2008 McGraw-Hill Companies. All Rights Reserved. 42 Immunity and Infection Chapter 13