Lecture Notes

Chapter 20 Sexually Transmitted Diseases

Modified: 2007-05-18

• Chlamydia (NGU)
  • Bacterium--Chlamydia trachomatis is the cause, many cases (4 million/year)
  • Symptoms
    • clear discharge, mild discomfort on urination
    • can be asymptomatic
  • Treatment
    • does not respond to penicillin
    • azithromycin or doxycycline used
    • failure to treat can lead to complications including pelvic inflammatory disease
• HPV (human papilloma virus, genital warts)
  • around 3 million new cases/year
  • Diagnosis
    • warts near urethra, on penis, or vulva
    • appearance is diagnostic
  • Treatment
    • podophyllum or tricholoroacetic acid
    • liquid nitrogen
    • laser therapy
    • all need to be repeated, virus remains in body
    • interferon
• Genital Herpes
  • virus--Herpes simplex II (Herpes simplex I usually non-genital, but oral sex...)
  • Symptoms
    • painful bumps or blisters
    • last a few weeks, then dormant
    • four recurrences/year is average
    • stress can cause recurrence
    • fatal for infants
  • Treatment
    • none
    • acyclovir eases pain and shrinks sores
    • pain and sores milder after time
• HIV Infection and AIDS
  • First cases in 1981 in San Francisco Gay community
  • AIDS virus identified in 1984 by Gallo and/or Montagnier
  • HIV-1--most cases, HIV-2--found mostly in Africa
  • AIDS Questionnaire
  • An Epidemic?
    • 250K + deaths
    • 500K + infected in U.S.
    • 5-10M infected in world
    • But, as a disease, fragile virus, transmitted under special conditions
  • Transmission
    • AIDS is transmitted via:
      • sexual intercourse (vaginal or anal)
      • contaminated blood
      • contaminated needles
      • to infant during childbirth
    • Risks are greatest:
      • in anal intercourse
      • with more partners
      • with risky partner (HIV positive, IV drug user, hemophiliac)
      • for heterosexual females
  • The Disease
    • HIV infection stages
      • initial infection--no symptoms, antibodies within 2 to 8 weeks
      • asymptomatic carrier--7 to 9 years
      • lymphdenopathy--swollen lympth nodes, night sweating, fever, loss of weight, diarrhea, fatigue
      • AIDS--infected by life-threatening opportunistic infections, T4 cell count drops
  • Diagnosis
    • ELISA--enzyme-linked immunosorbent assay
      • detects HIV antibodies
      • used for mass screening of blood
    • Western Blot test
  • Treatment
    • no cure
    • AZT--azidothymidine
      • stops HIV replication
      • cannot be used by some
    • DDI--dideoxyinosine
      • slows HIV replication
    • DDC--dideoxcytidine
      • slows HIV replication
    • protease inhibitors
      • attack viral enzyme--protease
    • HIV genetic Resitance?
      • see: http://www.wired.com/news/medtech/0,1286,66198,00.html
• Gonorrhea (the Clap, the Drip)
  • Oldest of STDs, usually occurs from vaginal intercourse
  • Symptoms
    • bacterial inflamation of urethra
    • clear discharge at first
    • changes to purulent discharge
    • burning sensation on urination
    • females can be asymptomatic and, if untreated, can lead to complications
  • Diagnosis
    • make a bacterial culture
  • Treatment
    • treat with penicillin or tetracycline
    • resistant strains require ceftriaxone
• Syphilis
  • Since 1400s, could be West to East migrant, caused by Treponema pallidum
  • Symptoms
    • chancre--primary stage
    • body rash--variable, painless--secondary stage
    • no symptoms--latent stage
    • cardiovascular or neural symptoms--tertiary stage (10-40 years after infection)
  • Diagnosis
    • blood tests (VDRL)
  • Treatment
    • large doses on long-acting antibiotics, especially penicillin
• Viral Hepatitis
  • liver disease
  • three types: A, B, non-A non-B
  • type B transmitted via sexual means
  • vaccine for type B
• Pubic Lice (crabs)
  • lice
  • transmitted via sexual or other contact
  • use special shampoos
• Other Infections
  • Vaginitis
    • Monilia--yeast infection
    • Trichomoniasis--STD
    • Nonspecific Vaginitis
    • Cystitis--E. coli
    • Prostatitis--E. coli
  • Prevention
    • wash and dry vulva
    • do not use feminine products
    • wear cotton underwear
    • wear loose clothing
    • reduce sugar and carbohydrates in diet
    • wipe from front to back
    • douche with vinegar

• URLs
  • STD's
  • Sexually Transmitted Diseases--from CDC
  • Safer Sex--from Wikipedia
  • Safer Sex Menu--from Williams College
  • The Body--comprehensive AIDS resource/information page
    • The first 500,000 AIDS cases--data summary, includes graphs
  • Chlamydia trachomatis--from CDC
  • Genital warts--general information from NIH
  • Genital warts--article
  • HIV Testing--nice series of pages on AIDS testing
  • HIV Testing--from FDA, list of tests including home tests
  • HIV Testing Options--from The Body
  • Western Blot AIDS test--From Wikipedia
  • Gonorrhea--information about from NY state department of health
  • Syphilis--from Wikipedia
  • Syphilis and yaws--from New York Times, story about origin of syphilis
  • Pubic lice--from CDC
  • Vaginitis--information about from Planned Parenthood