Sexually Transmitted Diseases

1. Sexually Transmitted Diseases Chapter 14

2. Estimated STD Incidence and Prevalence Estimated Annual Estimated Incidence Prevalence Trichomoniasis 7,400,000 n/a HPV infection 6,200,000 20,000,000 Chlamydia 2,800,000 1,900,000 Genital herpes 1,600,000 45,000,000 Gonorrhea 718,000 n/a Hepatitis B 81,000 1,250,000 Syphilis (all stages) 61,000 n/a HIV infection 40,000 900,000 Because viral STDs are incurable, the number of currently infected people capable of transmitting the infection (prevalence) greatly exceeds the annual number of new cases (incidence).

3. The Major STDs • HIV/AIDS • Chlamydia • Gonorrhea • Pelvic inflammatory disease • Genital warts (HPV infection) • Genital herpes • Hepatitis B • Syphilis

4. Acquired Immunodeficiency Syndrome (AIDS) • Leading cause of death worldwide for people ages 15–59 years • Worldwide, more than 40 million people are infected with human immunodeficiency virus (HIV); more than 1 million Americans are infected • HIV infection = a chronic, progressive disease that damages the immune system • AIDS = a generally fatal, incurable, sexually transmitted disease; severe stage of HIV infection • HIV = virus that causes HIV infection and AIDS

5. HIV Infection and AIDS • Over time, HIV damages the immune system, signaled by the loss of CD4-T cells (a type of white blood cell that helps coordinate the activity of the immune system) • A person with HIV infection is diagnosed with AIDS when he or she develops a marker condition or when the CD4 count drops below 200/µl • The asymptomatic period in an untreated adult averages 11 years

6. HIV Infection and AIDS: Transmitting the Virus • Sexual contact • Unprotected anal or vaginal intercourse is riskiest • Presence of lesions, blisters, or trauma • Male-to-female more likely than female-to-male • Direct exposure to infected blood • Injection drug use or sharing of other needles or blades • Blood and blood products (prior to testing) • Vertical or perinatal transmission = an HIV-infected woman to her fetus during pregnancy or childbirth or to her infant during breastfeeding • Risk is greatly reduced with treatment

7. HIV Infection and AIDS: Symptoms • Flulike symptoms of acute HIV infection may occur within a few days or weeks of infection • Opportunistic infections occur later, as the immune system weakens • Pneumocystis carinii pneumonia • Kaposi’s sarcoma • Frequent and difficult-to-treat vaginal yeast infections • Tuberculosis

8. HIV Infection and AIDS: Diagnosis • HIV antibody test detects the presence of antibodies to HIV, indicating infection • ELISA = first stage of test • Western blot = confirmatory test • Blood, urine, or oral fluid; rapid tests are available • May take up to 6 months following infection for antibodies to appear • HIV RNA assay measures the amount of the HIV virus in the blood; used to detect HIV infection in the earliest stages and to track the status of the infection

9. HIV Infection and AIDS: Treatment • Antiviral drugs • Reverse transcriptase inhibitors • Protease inhibitors • Fusion inhibitors • Drugs to prevent and treat opportunistic infections • Cost, access, side effects, effectiveness

10. HIV Infection and AIDS: Prevention • Abstinence is the only truly safe option unless you are in a long-term monogamous relationship with an uninfected partner • Don’t drink or use drugs in sexual situations • Limit the number of partners, especially those who have engaged in risky behavior; remember that many people are not truthful about their sexual history • Use latex condoms correctly during every act of intercourse and oral sex • Avoid sexual contact that could cause cuts or tears • Don’t share needles, syringes, or anything that could have blood on it • Get screened, get tested, get vaccinated for hepatitis B

11. Chlamydia • Caused by the bacterium Chlamydia trachomatis • Can cause PID, infertility, epididymitis, urethritis • Often asymptomatic • Diagnosed with urine or lab tests • Treated with antibiotics

12. Gonorrhea • Caused by the bacterium Neisseria gonorrhoeae, which affects mucous membranes • Can cause PID, infertility, epididymitis, urethritis, rashes, arthritis; in infants, it can cause the serious eye infection gonococcal conjunctivitis • Often asymptomatic in women; in men, it causes urinary discomfort and penile discharge • Diagnosed with urine or lab tests • Treated with antibiotics; many strains are resistant

13. Pelvic Inflammatory Disease (PID) • PID = an infection that progresses from the vagina and cervix to the uterus, oviducts, and pelvic cavity • Common following untreated cases of gonorrhea or chlamydia • Leading cause of infertility in young women; also increases risk of ectopic pregnancy and chronic pelvic pain • Symptoms highly variable • Treated with antibiotics; may require hospitalization

14. Genital Warts • Viral infection characterized by growths on the genitals; also called condyloma or genital HPV infection; caused by infection with human papillomavirus (HPV) • Most of the more than 20 million infected Americans have no symptoms but can still transmit the virus • Infected tissue may appear normal or may have obvious bumps or large warty growths • Treatment does not eliminate the infection • HPV infection is the key cause of cervical cancer

15. Genital Herpes • Persistant viral infection affecting about 45 million American adults; infants can be infected during birth • HSV-1 usually causes cold sores • HSV-2 usually causes genital herpes • Symptoms = recurrent outbreaks of painful genital lesions; often asymptomatic • Diagnosed from symptoms or blood test • Treatment with antivirals can reduce the frequency and severity of outbreaks; the virus remains in the body and can be transmitted even if no lesions are present

16. Hepatitis B • Inflammation of the liver that can cause permanent damage to the liver and death • Some people recover, some become chronic carriers, some develop chronic liver disease or liver cancer • Hepatitis B virus can be transmitted sexually and through close nonsexual contact • Symptoms may include flulike illness • Jaundice = increased bile pigment levels, causing yellowing of the skin and whites of the eyes • Diagnosed with blood tests • No cure, but a vaccine is available

17. Syphilis • Caused by the spirochete Treponema pallidum; potentially fatal if not treated • Symptoms at different stages of infection • Primary syphilis = an ulcer called a chancre • Secondary syphilis = flulike symptoms and a skin rash • Late, or tertiary, syphilis = asymptomatic or symptoms of severe organ damage • Diagnosed with blood tests • Treated with antibiotics • Infants can also be infected

18. Other STDs • Trichomoniasis (Trich) • Bacterial vaginosis (BV) • Pubic lice (crabs)

19. What You Can Do • Education • Diagnosis and treatment • Prevention • Abstain • Mutually monogamous relationship with one uninfected partner • Plan ahead for and practice safer sex

20. Sexually Transmitted Diseases Chapter 14