The document discusses sexually transmitted infections (STIs), also known as sexually transmitted diseases (STDs). It provides information on the major STDs including HIV/AIDS, hepatitis, syphilis, chlamydia, gonorrhea, herpes, and human papillomavirus. It describes symptoms, modes of transmission, testing, and treatment for each STI. The document emphasizes that STDs remain a major public health issue, with millions of new cases occurring each year in the United States. Education and prevention are key to reducing the spread of STDs.

1. Chapter 18
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2. The Major STDs
 Also known as sexually transmitted infections (STIs)
 Spread of an infection from person to person mainly
through sexual activity
 STDs that pose a major health threat:
1. HIV/AIDS
2. Hepatitis
3. Syphilis
4. Chlamydia
5. Gonorrhea
6. Herpes
7. Human papillomavirus (HPV)
 CDC (2008) estimated 65 million Americans were infected
with an STD, and about 19 million Americans become
newly infected with an STD each year
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3. Table 18.1 Annual new cases of STDs in the
United States
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4. Table 18.2 Sexually transmitted pathogens
and associated diseases
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5. HIV Infection and AIDS
 Human immunodeficiency virus (HIV) is the
virus which causes AIDS (acquired
immunodeficiency syndrome)
 Leading cause of death in some parts of the
world
 Approximately 65 million people around the
world have been infected with HIV since the
epidemic began
 Nearly 1% of the world’s population
 About 3 million new infections per year
 25% of HIV-infected Americans are unaware
of their condition
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6. What is HIV Infection?
 Chronic disease that progressively damages the
body’s immune system
 HIV attacks and invades CD4 T-cells, monocytes and
macrophages
 HIV enters a human cell and converts its own genetic
material, RNA, into DNA
 People with AIDS are vulnerable to a number of
serious opportunistic (secondary) infections
 Once initial symptoms resolve, the asymptomatic
period may last from 2 to 20 years
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7. Transmitting the Virus
 HIV lives only within cells and body fluids
 Three primary means of transmission:
 Specific kinds of sexual contact
 Direct contact to infected blood
 HIV-infected women to her fetus or to infant during
breastfeeding
 Not through casual contact
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8. Figure 18.1 The general pattern of untreated
HIV infection
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9. Populations of Special Concern for
HIV Infection
 Most common means of exposure:
 Sexual activity between men
 Injection drug use
 Heterosexual contact
 African American men and women are
vastly overrepresented among U.S.
people newly diagnosed with AIDS
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10. Figure 18.2 Routes of HIV transmission among
Americans
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11. Symptoms of HIV Infection
 Within a few days or weeks, some people
will develop flulike symptoms
 Specialized test HIV RNA assay
 Symptoms take months or years to
develop, but as immune system weakens,
variety of symptoms develop
 Pneumocystis pneumonia (fungal infection)
 Kaposi’s sarcoma
 Difficult-to-treat yeast infections in women
 Tuberculosis
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12. Diagnosing HIV Infection
 Most common tests check for the
presence of antibodies to the virus
 HIV antibody test
 ELISA (first test)
 Western blot or immunoflourescence assay
is done to confirm results
 If HIV positive, the next step is to
determine the disease’s severity to plan
appropriate treatment
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13. Diagnosing AIDS
 HIV-positive and either has developed an infection
defined as an AIDS indicator or has a severely damaged
immune system
 Reporting
 All diagnosed cases of HIV or AIDS must be reported to public
health authorities
 Treatment
 No cure
 Antiviral drugs
 Postexposure prophylaxis (PEP)
 Treatments for opportunistic infections
 HIV and pregnancy
 Treatment challenges
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Sexually Transmitted Diseases 13

14. Figure 18.3 The life cycle of HIV: How antiviral
drugs work
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15. What About a Vaccine?
 Vaccines are being tested in humans
 Licensed AIDS vaccine is not estimated
to be at least a decade away
 Some experts concede the possibility that a
vaccine may never be developed
 How can you protect yourself?
 Make careful choices about sexual activity
 Don’t share drug needles
 Participate in an HIV education program
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16. Figure 18.4 What’s risky and what’s not: The
approximate relative risk of HIV transmission of various
sexual activities
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17. Chlamydia
 Most prevalent bacterial STD in the U.S.
 Can cause sterility in men and women
 In women, it can lead to pelvic inflammatory disease
and ectopic (tubal) pregancy
 In men, chlamydia is the most common cause of
epididymitis, and causes half of all cases of urethritis
 Symptoms
 Usually asymptomatic in women
 Vaginal discharge, burning with urination, watery
discharge from penis, pain around testicles and in
lower abdominals
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18. Chlamydia
 Diagnosis
 Examination of tissue samples or urine
 Treatment
 Once diagnosed, infected person and partner
are given antibiotics
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19. Gonorrhea
 350,000 new cases reported to the CDC in
2007
 Bacterial infection
 Can cause sterility, arthritis, heart problems,
PID, ectopic pregnancy, urethritis, and
gonococcal conjunctivitis in infants of
infected mothers
 Symptoms
 Usually asymptomatic in women, though frequent
burning during urination, menstrual irregularities, pelvic
pain, and discharge may occur
 Thick yellow-white discharge, and painful urination in
men
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20. Gonorrhea
 Diagnosis
 Microscopic exam of discharge can
diagnose infection
 Treatment
 Oral antibiotics can be taken for treatment
○ Growing number of drug-resistant strains of
gonorrhea is a major concern
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21. Pelvic Inflammatory Disease
 Leading cause of infertility in young women
 Symptoms
 Long and painful periods, discharge, spotting, low
abdominal pain, fever, chills, nausea, and vomiting
 Diagnosis
 Diagnosis made on basis of symptoms, physical
examination, ultrasound, and laboratory tests
 Treatment
 Antibiotics and hospitalization are normally required
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22. Human Papillomavirus Infection
 Most common STD in the U.S.
 Causes a variety of human diseases:
 Common warts
 Genital warts
 Genital cancers
 Highly contagious
 New vaccination for HPV: Gardasil
 Protects against four types of HPV virus that account for
90% of genital warts and 70% of cervical cancers
 Most effective before the onset of sexual activity
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23. Human Papillomavirus Infection
 Symptoms
 Small bump on the skin or a large, warty growth
 Cauliflower-like mass
 May cause irritation and bleeding
 Diagnosis
 Diagnosed based on the appearance of lesions
 Often detected during routine PAP tests
 Treatment
 Treatment focuses on reducing the number and
size of warts
○ Cryosurgery (freezing)
○ Electrocautery (burning)
○ Laser surgery
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24. Genital Herpes
 1 in 5 adults in the U.S. has genital herpes
 Two forms cause genital herpes and oral-labial
herpes
 HSV 1 (Type 1)
○ Associated with cold sores and fever blisters
○ Oral-labial herpes
○ 50-80% of U.S. adults have antibodies to HSV-1
 HSV 2 (Type 2)
○ Almost always sexually transmitted
○ Usually occurs during adolescence and early adulthood
○ Approximately 22% of adults have antibodies to HSV 2
 Remains in the body for life
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25. Genital Herpes
 Symptoms
 90% of infected people have no symptoms
 First episode causes flulike symptoms and genital
lesions
 Virus remains alive in an inactive state and an
outbreak can occur at any time
 Diagnosis
 Diagnosed through examination of sores and culturing
of fluid taken from sores
 Treatment
 No cure
 Antiviral drugs taken at the beginning of an outbreak
can shorten the severity and duration of symptoms
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26. Hepatitis B
 Inflammation of the liver which can cause
serious and permanent damage to the liver
 Highly contagious but preventable with vaccine
 Transmitted through the exchange of bodily
fluids
 Symptoms
 Flulike symptoms, nausea, vomiting, dark-colored
urine, abdominal pain, and jaundice
 Diagnosis and treatment
 Diagnosed through a blood test
 No cure
 Prevention
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27. Syphilis
 Can be effectively treated with antibiotics
 Symptoms
 Primary phase: 10-90 days after exposure
○ Characterized by painless ulcers, called chancres
 Secondary phase: 3-6 weeks after exposure
○ Characterized by flulike symptoms and highly contagious
skin rash
 Late, or tertiary, phase
○ Damage to organs, dementia, cardiovascular damage,
blindness, and death
 Diagnosis and treatment
 Diagnosed by examination of infected tissues and
with blood tests
 Treated by antibiotics but damage from late stages
of infection can be permanent
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28. Other STDs
 Trichomoniasis
 Most common curable STD among young
women
 Single-celled organism
 Bacterial vaginosis (BV)
 Abnormal vaginal discharge caused by
unhealthy species of normal vaginal bacteria
 Pubic lice and scabies
 Contagious parasitic infections
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29. What You Can Do
 Education
 Diagnosis and treatment
 Get vaccinated
 Be alert for symptoms
 Get tested
 Inform your partners
 Get treated
 Prevention
 Talk openly about your concerns
 Know your potential partner
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30. Chapter 18
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