Chapter 17 Summary

  1. Nineteen million new cases of sexually transmitted diseases (STDs) occur annually in the United States. STDs are caused by lice, mites, protozoans, bacteria, and viruses. In spite of medical advances, STDs remain a major public health problem. They also bolster a perception of sex as something dangerous or immoral.
  2. Skin infestations that can be transmitted sexually include pubic lice and scabies. Pubic lice attach themselves to hair shafts, especially in the pubic region. Scabies mites burrow under the surface of the skin. Both infestations can cause severe itching but do not otherwise threaten health. Pubic lice and scabies mites can be eliminated by use of insecticidal lotions or shampoos.
  3. Trichomoniasis is an infection of the vagina or urethra with a protozoan. In women it causes discomfort, a vaginal discharge, and the urge to urinate frequently. In men, the infection is usually asymptomatic. It is generally eliminated by a single oral dose of Flagyl.
  4. Syphilis is caused by infection with the bacterium Treponema pallidum. The disease has several stages. Primary syphilis is marked by a sore (chancre) at the site of infection. Some weeks later, a rash and fever occur (secondary syphilis). The infection then becomes latent, but it may eventually attack a variety of organ systems (tertiary syphilis) and cause death. The disease is readily curable with penicillin in its early stages.
  5. Gonorrhea is caused by infection with the bacterium Neisseria gonorrhoeae. In men it usually infects the urethra, causing painful urination. In women it can infect the cervix, causing a vaginal discharge. The infection in women is commonly asymptomatic, but it can spread to the internal reproductive tract, causing pelvic inflammatory disease (PID) and reduced fertility. Rectal and oral infections can occur in either sex. Gonorrhea can be treated with antibiotics, but antibiotic resistance is an increasing problem.
  6. Infection with the bacterium Chlamydia trachomatis is very common. It can cause a urethral or vaginal discharge and painful urination, but many infected men and women do not have symptoms. Anal and oral infections can occur. Chlamydia is readily treatable with antibiotics. In women, untreated chlamydia infections can lead to PID.
  7. Molluscum contagiosum is a common skin condition caused by a pox virus. It consists of small skin growths that usually disappear permanently after a few months. Although any kind of interpersonal contact can allow for transmission, molluscum in the genital area is usually the result of sexual transmission.
  8. Genital herpes is a very common condition caused by infection with the herpes simplex virus type 1 or 2 (HSV-1 or HSV-2). It causes an outbreak of sores at the site of infection, which is usually somewhere in the anogenital region but can also be in the mouth. The initial out-break heals spontaneously, but it may be followed by further outbreaks at the same location that recur for the remainder of the person’s life. Herpes infection is incurable, but outbreaks can be limited by antiviral drugs.
  9. Human papillomaviruses (HPV) cause genital warts and other lesions of the genital skin and urogenital tract. Genital warts can be removed by a variety of treatments. Some HPV types (not those that cause bulky, raised genital warts) infect the cervix and are the principal cause of cervical cancer and anal cancer. HPV vaccines are available; they should be administered to a young person before he or she becomes sexually active.
  10. Hepatitis A and B are viral infections of the liver that can be acquired sexually as well as by other routes. Anal sex (especially anilingus) are the sexual behaviors most likely to transmit hepatitis A. Hepatitis B is transmitted by coitus or oral sex; in a minority of cases it leads to chronic liver disease and liver cancer. No cure exists for either form of hepatitis, but effective vaccines are available.
  11. Acquired immune deficiency syndrome (AIDS) is caused by infection with the human immunodeficiency virus (HIV). The virus originated in central Africa, but a worldwide pandemic began with outbreaks in gay male communities in the United States in the late 1970s. Transmission now occurs by both male–female and male–male sexual contacts (principally by coitus and anal penetration), as well as by exposure to contaminated blood. Female–female transmission is uncommon.
  12. HIV infection is marked by an acute illness followed by a several-year asymptomatic period. Eventually the infection impairs the person’s immune system to the point that certain opportunistic infections and cancers may occur. Symptomatic AIDS is a life-threatening condition that cannot be cured, but it may be held in check with a combination of drugs that interfere with various stages of the virus’s replication cycle.
  13. Women and men can reduce their risk of acquiring STDs by a variety of means. Complete sexual abstinence offers complete protection. Sexually active people can reduce their risk by keeping their number of sexual partners low (ideally, by forming a mutually monogamous relationship), by discussing STDs and sexual history with prospective partners, by getting tested for STDs, and by engaging in relatively low-risk sexual behaviors as an alternative to coitus or anal sex. Careful and consistent use of condoms is key to lowering the risk of acquiring and transmitting STDs.