© 2009 McGraw-Hill Higher Education. All rights reserved. Chapter Thirteen: Preventing Infectious Diseases

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. Pathogens Viruses Prions Bacteria Fungi Protozoa Rickettsia Parasitic worms

© 2009 McGraw-Hill Higher Education. All rights reserved. Chain of Infection

© 2009 McGraw-Hill Higher Education. All rights reserved. Chain of Infection Agent: Causal pathogen Reservoir: Pathogen’s environment Portal of exit Mode of transmission –Direct –Indirect Port of entry New host

© 2009 McGraw-Hill Higher Education. All rights reserved. Stages of Infection Incubation stage -asymptomatic Prodromal stage-general pre-symptoms Clinical stage-acute Decline stage- recovery begins Recovery stage - convalescence

© 2009 McGraw-Hill Higher Education. All rights reserved. Body Defenses Mechanical Cellular-chemical (“immune system”)

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. Immune Response

© 2009 McGraw-Hill Higher Education. All rights reserved. Diphtheria Whooping cough Hepatitis B Hepatitis A Haemophilus influenza type B Tetanus Rubella (German measles) Measles (red measles) Polio Mumps Chicken pox Meningococcus Pneumococcal infection Childhood diarrhea Human papillomavirus infections Shingles Immunizations Vaccinations should be given against the following infectious conditions:

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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.

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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)

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. Diagnosis of HIV Infection Enzyme linked immunosorbent assay (ELISA) Western BLOT test PCR

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. HIV/AIDS on the World Stage

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. 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?

© 2009 McGraw-Hill Higher Education. All rights reserved. UROGENITAL AND SEXUALLY TRANSMITTED DISEASES

© 2009 McGraw-Hill Higher Education. All rights reserved. Anatomy Review — Urinary Urinary System

© 2009 McGraw-Hill Higher Education. All rights reserved. Anatomy Review — Urinary

© 2009 McGraw-Hill Higher Education. All rights reserved. Anatomy — Female Reproductive Female Reproductive

© 2009 McGraw-Hill Higher Education. All rights reserved. Anatomy — Male Reproductive

© 2009 McGraw-Hill Higher Education. All rights reserved. Bacterial Urogenital Diseases Urinary Tract Infections (UTIs) –Urethritis –Cystitis –Prostatitis

© 2009 McGraw-Hill Higher Education. All rights reserved.

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

© 2009 McGraw-Hill Higher Education. All rights reserved. Number of Lifetime Sexual Partners among Adults (Age 20-59)

© 2009 McGraw-Hill Higher Education. All rights reserved. Sexually Transmitted Diseases HIV/AIDS Chlamydia Human papillomavirus Gonorrhea Herpes simplex Syphilis Pubic lice Vaginal infections Cystitis and urethritis Molluscum contagiosum

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. Chlamydia Female Male

HPV - Genital warts

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

© 2009 McGraw-Hill Higher Education. All rights reserved. Viral STDs — Warts Human Papilloma virus (genital warts)

© 2009 McGraw-Hill Higher Education. All rights reserved. Prevalent STDs Gonorrhea –Bacterium N. gonorrhoea –Symptoms: painful urination, discharge –Treated with antibiotics; some strains are drug- resistant

© 2009 McGraw-Hill Higher Education. All rights reserved. Bacterial Sexually Transmitted Diseases (STDs) Gonorrhea Neisseria gonorrhoeae

© 2009 McGraw-Hill Higher Education. All rights reserved. Gonorrhea

© 2009 McGraw-Hill Higher Education. All rights reserved. Incidence of Gonorrhea

© 2009 McGraw-Hill Higher Education. All rights reserved. Incidence of Gonorrhea

© 2009 McGraw-Hill Higher Education. All rights reserved. Incidence of Gonorrhea

© 2009 McGraw-Hill Higher Education. All rights reserved. Severe gonorrhea

© 2009 McGraw-Hill Higher Education. All rights reserved. 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

© 2009 McGraw-Hill Higher Education. All rights reserved. Bacterial STDs — Syphilis Treponema pallidum A spirochete

© 2009 McGraw-Hill Higher Education. All rights reserved. Chancre - primary lesion

© 2009 McGraw-Hill Higher Education. All rights reserved. Seconday/Tertiary Syphilis tertiary secondary

© 2009 McGraw-Hill Higher Education. All rights reserved. Syphilis Incidence

© 2009 McGraw-Hill Higher Education. All rights reserved. Syphilis Incidence

© 2009 McGraw-Hill Higher Education. All rights reserved. Syphilis Incidence

© 2009 McGraw-Hill Higher Education. All rights reserved. Syphilis Incidence

© 2009 McGraw-Hill Higher Education. All rights reserved. Pubic lice (“crabs”) Cause intense itching Treated with prescription and OTC drugs

© 2009 McGraw-Hill Higher Education. All rights reserved. Crabs! Pubic lice

© 2009 McGraw-Hill Higher Education. All rights reserved. Herpes - virus Herpes simplex HSV 1 (oral) and HSV II (genital) Painful blisterlike sores Pattern of recurrences Persistent; treated with antiviral drugs

© 2009 McGraw-Hill Higher Education. All rights reserved.

Prevalent STDs Vaginal infections –Yeast infection (Candida albicans) –Bacterial vaginosis (BV) –Protozoa Trichomonas vaginalis Cystitis (infection of bladder) Urethritis (infection of urethra) –Caused by various pathogens –Treated with antibiotics

© 2009 McGraw-Hill Higher Education. All rights reserved. Mulluscum contagiosum - virus

© 2009 McGraw-Hill Higher Education. All rights reserved. Mulluscum contagiosum

© 2009 McGraw-Hill Higher Education. All rights reserved. Chapter Thirteen: Preventing Infectious Diseases Discussion questions Should people be forced to get vaccines? Does the CDC do a good job of informing the public?