Chapter Thirteen

1. Chapter Thirteen Immunity and Infection

2. Viruses Bacteria Fungi Protozoan Parasitic worms Prions Major Pathogens Disease producing agent which could produce toxins

3. Chain of Infection

4. Identify Body Defenses

5. Identify Immune Response Against Pathogens

6. Inflammatory Response • When the body has been infected, one of the responses is the Inflammatory Response • Special cells release histamine which causes heat, swelling, and redness of that area • White blood cells attack the invader, attempting to destroy them

7. How Does One Achieve Immunity? • After an infection, lymphocytes created during the amplification phase of the immune response serve as memory T and B cells • They continue to circulate in the blood and lymphatic system for years or even longer • If the same antigen enters the body, the T and B recognize this and destroy it • The ability to have lymphocytes remember previous infections is known as acquired immunity

8. 5 Stages of an Infection • Incubation stage • Prodromal stage • Clinical stage • Decline stage • Recovery stage

9. Immunizations • Vaccinations are when the immune system is given an antigen which is not considered dangerous • The body produces antibodies, which prevent serious infection against that particular disease • Vaccines are made by either weakened pathogens or killed pathogens, which still illicit the production of antibodies (active immunity), or antibodies can be injected (passive immunity) to create temporary immunity

10. Allergies: The Body’s Defense Gone Haywire • 50 million Americans are affected by allergies • This is a result from a hypersensitive and overactive immune system • The immune system mounts an attack on a harmless substance • The results create the unpleasant and potentially serious symptoms of an allergy

11. Pollen Animal dander Dust mites and cockroaches Medication Types of metals Mold and mildew Foods Insect stings Plants Substances found in cosmetic products Allergens

12. The Allergic Response • Most allergic reactions are due to the production of immunoglobulin E (IgE) • Mast cells release large amounts of histamines and other compounds into the surrounding tissue • Histamine has many effects, such as congestion, redness, swelling, etc. but the most serious kind of allergic reaction is anaphylaxis

13. Meningitis Tuberculosis Pneumonia Strep Throat and other streptococcal infections Urinary Tract Infections Toxic Shock Syndrome and other staphylococcus infections Lyme disease and other Tickborne infections Ulcers Tetanus Pertussis Bacterial Infections Antibiotics interrupt the new production of bacteria by damaging them

14. Common Cold Influenza Poliomyelitis Warts Chicken Pox, Cold sores, and herpes virus infections Viral Encephalitis Viral Hepatitis Viral Infections Treatment is the use of anti-viral medications

15. Fungal Infections • A fungus is a primitive plant • 50 of thousands of fungi cause disease among humans • Candida albicans is a common fungus found naturally in the vagina of most women, which causes infections • Other common forms are athlete’s foot, jock itch, and ringworm • Fungal infections can be deadly in people with impaired immune systems

16. Protozoan Infections • Single-celled organisms, which alternate between activity and inactivity • Common infections include: • Trichomoniasis • Trypanosomiasis • Amoebic dysentery

17. Parasitic Worms • Considered the largest organism that can enter the body to cause infection • Worms, including the tapeworm and hookworm, can grow to a length of many feet, especially in the intestinal tract • Worm infections can originate from contaminated food or drink

18. Prions • Known as ‘proteinaiceous infectious particles’ • Prions lack DNA or RNA and consist of only protein • They spread by triggering normal proteins to change their structure to the abnormal, damaging form • Examples are: • Creutzfeldt-Jakob a.k.a. ‘Mad Cow’ • Scrapie

19. SARS E. coli Hantavirus Monkey Pox Ebola Avian flu Selected Infections of Concern

20. Drug Resistance Poverty Breakdown of Public Health Measures Environmental Changes Travel and Commerce Mass Food Production an Distribution Human Behavior Factors Contributing to Emerging Infections

21. HIV Infection • It is estimated that more than 60 million people have been infected with HIV • By 2004, it is estimated that 1 million Americans are living with HIV • HIV infection continues to spread, even though death rates have declined among Americans, however, a cure has not been discovered

22. What is HIV? (Human Immuno-Deficiency Virus) • Cause – HIV, virus that attacks the CD4 T cells of the immune system • Spread • direct contact involving the exchange of bodily fluids (blood, semen, vaginal secretions) • through infected blood products • prenatal transmission (mother to fetus) or during breast-feeding

23. HIV Infection (cont.) (Human Immuno-Deficiency Virus • Following several weeks after becoming infected, about half of those develop flu-like symptoms (Primary Infection Phase) • Experts believe that half of all HIV cases are spread during this phase • The next phase is known as the Chronic Asymptomatic Stage which can last 2-20 years • During this time, the virus is progressively infecting and destroying cells of the immune system

24. Populations of Special Concern for HIV Infection • Although the transmission of HIV occurs through specific individual behaviors, high levels of infection within certain groups are tied to social, cultural, and economic factors • Such groups that are affected are: • Women • Gay men • Men who are having sex with other men but do not considered themselves ‘gay’ • Minorities • Poor

25. Diagnosis of HIV Infection • Enzyme Linked Immunosorbent Assay (ELISA) • Western BLOT test • HIV Replication Capacity (viral fitness) • Rapid HIV test, home tests, and non-blood tests are currently available

26. Treatment for HIV/AIDS • No cure at this time • Combination drugs reverse transcriptase inhibitors and protease inhibitors; both assist the body by disallowing replication of the virus in various cycles • Fusion inhibitors

27. How Can You Protect Yourself? • Learn the sexual history and HIV status of your partner • Limit the number of sexual partners • Use lubricated condoms correctly and consistently • Avoid contact with body fluids • Curtail the use of drugs

28. Prevention of HIV Infection, cont’d • Never share hypodermic needles • Refrain from sex with known injectable drug users • Get regular tests for STD’s • Participate in an HIV Education Program

29. Chlamydia • Chlamydia (bacterium) – most prevalent in the U.S. • Symptoms in males include: • Painful urination • Slight watery discharge • Pain in the testes • Symptoms in women include: • Vaginal discharge • Burning urination • Lower abdominal pain • Diagnosis: urine sample • Treatment: antibiotics

30. Gonorrhea • Gonorrhea (bacteria) – estimated 700,000 new cases in the United States annually • Symptoms for men: • Urethritis (yellowish discharge) • Swollen lymph glands of the groin • Symptoms for women: • Most females are asymptomatic but will have some discharge and pain during urination • Diagnosis: culture from urine or discharge sample • Treatment: antibiotics

31. Pelvic Inflammatory Disease • PID occurs when the initial infection of either gonorrhea or chlamydia enters beyond the cervix • Even if the disease is treated successfully, 25% of women will have long-term problems • PID is the leading cause of infertility for young women • Diagnosis usually requires a pelvic exam and lab tests • Treatment is usually with antibiotics

32. Human Papillomavirus (HPV) • HPV (virus) – genital warts which can lead to cervical cancer in women and penile cancer in men • HPV is very contagious and difficult to control since many infected people seem to be asymptomatic • Symptoms include: growths that cause irritation and bleeding • Diagnosis: appearance of the lesions or biopsy • Treatment: cryosurgery or laser surgery

33. Genital Herpes • Caused by HS2 (Herpes Simplex 2 virus) which is sexually transmitted even though the partner may appear asymptomatic • Herpes lesions may contain and transmit HIV • Symptoms include: flu-like symptoms accompanied with painful lesions around the genitals • Diagnosis: sample of fluid from lesions or blood test • Treatment: antiviral medications reduce symptoms even though a cure is not available

34. Hepatitis A, B, C • Virus • Inflammation of the liver • Symptoms – fever, nausea, abdominal pain, jaundice • Type A – associated with fecal contamination of food due to poor food handling • Type B – sexual contact, IV drug use, tattooing, piercing • Type C – similar to type B

35. Hepatitis B • Inflammation of the liver which can cause serious damage and sometimes result in death • Transmitted by blood and bodily secretions • Symptoms: many people do not have physical symptoms (silent symptoms), but may develop flu-like symptoms within several weeks of exposure • Diagnosis: blood tests • Prevention: vaccinations and preventive measures against infected bodily fluids

36. Syphilis • Caused by a spirochete (thin, corkscrew shaped bacterium) • Transmitted by passing the pathogen through breaks in the skin or mucous membranes via kissing, or sexual activity • Symptoms are the presence of ‘chancre’ or sores that are usually painless • Late Syphilis can damage many organs of the body, which eventually can lead to death • Diagnosis: blood test • Treatment: antibiotics

37. Other Prevalent STD’s • Vaginal infections (yeast) – can cause thrush, allowing colored discharges and itching. Protozoan infections are “trichomonisis.” • Bacterial vaginosis – common cause of abnormal vaginal discharge • Chancroid - bacterial infection, creating sores on the genitals • Public lice – ‘crabs’ that are highly contagious and feed on blood in and around the hairs • Scabies – parasites that deposit eggs beneath the skin, creating an intense itch

38. What Can You Do? • Education • Get Vaccinated • Be Alert for possible symptoms • Get Tested • Inform your partners • Get Treatment

39. Chapter Thirteen Immunity and Infection