Chapter Thirteen: Preventing Infectious Diseases

1. Chapter Thirteen: Preventing Infectious Diseases

2. Infectious Disease Transmission • Pathogen: A disease-causing agent • Epidemic: A highly significant increase in the number of cases of an infectious illness existing in a given time period in a given geographical area • Pandemic: An epidemic that has crossed national boundaries, thus achieving regional or international status • Example: HIV/AIDS

3. Pathogens • Viruses • Prions • Bacteria • Fungi • Protozoa • Rickettsia • Parasitic worms

4. Chain of Infection

5. Chain of Infection • Agent: Causal pathogen • Reservoir: Pathogen’s environment • Portal of exit • Mode of transmission • Direct • Indirect • Port of entry • New host

6. Stages of Infection • Incubation stage -asymptomatic • Prodromal stage-general pre-symptoms • Clinical stage-acute • Decline stage- recovery begins • Recovery stage - convalescence

7. Body Defenses • Mechanical • Cellular-chemical (“immune system”)

8. Divisions of the Immune System • Cell-mediated immunity • T cell-mediated • Humoral immunity • B cell-mediated • Acquired immunity • Naturally acquired immunity (NAI) • Response to naturally occurring pathogen • Artificially acquired immunity (AAI) • Response to immunization • Passively acquired immunity (PAI) • From extrinsic antibodies

9. Immune Response

10. Immunizations • Vaccinations should be given against the following infectious conditions: • Chicken pox • Meningococcus • Pneumococcal infection • Childhood diarrhea • Human papillomavirus infections • Shingles • Diphtheria • Whooping cough • Hepatitis B • Hepatitis A • Haemophilus influenza type B • Tetanus • Rubella (German measles) • Measles (red measles) • Polio • Mumps

11. Nosocomial Infections • Infections spread in conjunction with the delivery of health care services • Over 100,000 deaths/year are attributed to these infections • Clostridium dificile diarhea • MR.SA Staph aureus • Pseudomonas

12. The Common Cold (Acute Rhinitis) • Acute upper-respiratory-tract infection • Caused by different viruses • Common symptoms; usually last several days • Treatments manage symptoms but do not cure the infection • More severe symptoms may indicate flu, pneumonia, or another infection • Prevention: Handwashing

13. Shortening a cold Avoid touching portals of entry - prevents superinfection Zinc glycine gluconate lozenge at first signs of cold. Must take without orange juice or vitamin C for 3 hrs. Vitamin C (ascorbic acid) 500 mgs Netty pots- nasopharangeal lavage Rest and avoiding alcohol during sick phase.

14. Influenza • Acute viral infection • More serious than common cold • Especially dangerous for young children, pregnant women, older people • Annual vaccination • Risk of spread of highly virulent avian influenza

15. Tuberculosis • Bacterial infection of the lungs • Symptoms • Chronic coughing • Weight loss • Spread through coughing • Requires long-term treatment with antibiotics (6 months or longer) • Antibiotic-resistant strains are a concern

16. Pneumonia • Infectious respiratory conditions • May be bacterial, viral, fungal, rickettsial, mycoplasmal, or parasitic • Bacterial is most common, especially among people with other illnesses • Vaccination for pneumococcal pneumonia for children and older adults

17. Other Infectious Diseases • Mononucleosis (“mono”) • Viral infection characterized by weakness, fatigue, swollen glands, sore throat, and low-grade fever • Chronic fatigue syndrome • Characterized by severe exhaustion, fatigue, aches, and depression. New virus found! • Bacterial meningitis • Infection of the thin membranous coverings of the brain • Higher risk among college students living in residence halls • Immunization available

18. Other Infectious Diseases • Lyme disease (Boriella burgdorfii) • Bacterial infection transmitted by deer ticks • Hantavirus pulmonary syndrome • Extreme pulmonary distress • Transmitted from deer mice to humans • West Nile virus • Transmitted by mosquitoes • Flulike symptoms; may involve encephalitis • Tampon-related toxic shock syndrome

19. Viral Hepatitis • Inflammation of the liver • Symptoms • Fever, nausea, abdominal pain, jaundice • Types: • 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 • Type D – difficult to treat; found in type B sufferers; contact with bodily fluids • Type E – water contamination (rare) • Vaccination available for types A and B

20. HIV/AIDS • Human immunodeficiency virus (HIV) • Acquired immunodeficiency syndrome (AIDS) • HIV attacks the helper T cells of the immune system • Spread • Direct contact involving the exchange of body fluids (blood, semen, vaginal secretions) • Sharing of hypodermic needles • Infected blood products • Perinatal transmission (mother to fetus or newborn)

21. HIV/AIDS • HIV cannot be transmitted by sweat, saliva, or tears, even though trace amounts of HIV are observed • Women are at higher risk than men of contracting HIV from an infected partner • HIV concentration is higher in semen compared with vaginal secretions

22. Diagnosis of HIV Infection • Enzyme linked immunosorbent assay (ELISA) • Western BLOT test • PCR

23. The Course of HIV Infection • Newly infected may experience flu-like symptoms within 1 or 2 months of exposure • Symptoms disappear quickly • Immune system is unable to clear HIV from the body • Asymptomatic stage • Could last for months to over 12 years • Length depends on overall health, age, gender, strain of infection • Immune system worsens • Level of CD4 helper T cells • Opportunistic infections

24. Treatment of HIV Infection • No cure at this time • HAART (highly active antiretroviral therapy) can significantly reduce viral load • Antiviral drugs, usually taken in combination • Nucleoside/nucleotide reverse transcriptase inhibitors • Non-nucleoside reverse transcriptase inhibitors • Protease inhibitors • Fusion inhibitors • CCR5 antagonists • Drug resistance

25. HIV/AIDS on the World Stage

26. Prevention of HIV Infection • Learn the sexual history and HIV status of your partner • Limit the number of sexual partners • Use condoms correctly and consistently • Avoid contact with body fluids • Curtail the use of drugs • Never share hypodermic needles • Refrain from sex with known injectable drug users and other high-risk partners • Get regular tests for STDs • Do not engage in unprotected anal intercourse

27. Discussion questions 1) What are the easiest ways to prevent yourself from getting an infectious disease? 2) Why is it important to determine whether an infection is bacterial or viral and if bacterial finish the course of antibiotics. 3) Why is education an important part of preventing the spread of HIV? 4) Why is getting a vaccine important? 5) Food-borne diseases are problematic, what can be done to decrease the risk of contracting one?

28. UROGENITAL AND SEXUALLY TRANSMITTED DISEASES

29. Anatomy Review — Urinary • Urinary System

30. Anatomy Review — Urinary

31. Anatomy — Female Reproductive • Female Reproductive

32. Anatomy — Male Reproductive

33. Bacterial Urogenital Diseases • Urinary Tract Infections (UTIs) • Urethritis • Cystitis • Prostatitis

35. Bacterial Urogenital Diseases • Vaginitis • Toxic Shock Syndrome Gardnerella vaginalis Staphylococcus aureus type 1 Streptococcus spp.

36. Number of Lifetime Sexual Partners among Adults (Age 20-59)

37. HIV/AIDS Chlamydia Human papillomavirus Gonorrhea Herpes simplex Syphilis Pubic lice Vaginal infections Cystitis and urethritis Molluscum contagiosum Sexually Transmitted Diseases

38. Prevalent STDs • Chlamydia • Bacterium Chlamydia trachomatis • Urethritis • Left untreated, can cause pelvic inflammatory disease and infertility in women • Human papillomavirus (HPV) • Often asymptomatic • Can cause genital warts, cervical cancer • Vaccine; not curable

39. Chlamydia Male Female

40. HPV - Genital warts

41. Don’t turn the light out, you might miss something

42. Viral STDs — Warts • Human Papilloma virus (genital warts)

43. Prevalent STDs • Gonorrhea • Bacterium N. gonorrhoea • Symptoms: painful urination, discharge • Treated with antibiotics; some strains are drug-resistant

44. Bacterial Sexually Transmitted Diseases (STDs) • Gonorrhea Neisseria gonorrhoeae

45. Gonorrhea

46. Incidence of Gonorrhea

47. Incidence of Gonorrhea

48. Incidence of Gonorrhea

49. Severe gonorrhea

50. Prevalent STDs • Syphilis • Bacterium Treponema pallidum • Three stages: • Primary stage: Painless sore called a chancre • Secondary stage: General symptoms of illness • Late stage: May recur many years after initial contact; profound damage to many body systems • Left untreated, can cause death