What is the Definition of Sexually Transmitted Diseases (STDs)?

Sexually transmitted diseases (STDs) are transmitted sexually by someone who is infected. These infections are usually passed by intercourse, but can also be passed through other types of sex, such as oral sex.

STDs can be caused by viruses or bacteria. If you have ever had sex, you may be at risk for having an STD. You are at higher risk if you have had many sex partners, have had sex with someone who has had many partners, or have had sex without using condoms (rubbers).

Description of Sexually Transmitted Diseases (STDs)

Sexually transmitted diseases (also called venereal diseases) are among the most common infectious diseases in the U.S. today. At least 20 STDs have now been identified. They affect more than 10 million men and women in this country each year.

It is important to understand at least five key points about all STDs in this country today:

  • STDs affect men and women of all backgrounds and economic levels. They are most prevalent among teenagers and young adults. Nearly one-third of all cases involves teenagers.
  • The incidence of STDs is rising, in part because in the last few decades, young people have become sexually active earlier. Sexually active people today are also more likely to have more than one sex partner or to change partners frequently. Anyone who has sexual relations is potentially at risk for developing STDs.
  • Many STDs initially cause no symptoms. When symptoms develop, they may be confused with those of other diseases not transmitted through sexual contact. However, even when an STD causes no symptoms, a person who is infected may be able to pass the disease on to a sex partner. That is why many doctors recommend periodic testing for people who have more than one sex partner.
  • Health problems caused by STDs tend to be more severe and more frequent for women than men.
  • Some STDs can cause pelvic inflammatory disease (PID), a major cause of both infertility and ectopic (tubal) pregnancy. The latter can be fatal to a pregnant woman.
  • STD infections in women may also be associated with cervical cancer. One STD, genital warts, is caused by a virus associated with cervical and other cancers. The relationship between other STDs and cervical cancer is not yet known.
  • STDs can be passed from a mother to her baby before or during birth; some of these congenital infections can be cured easily, but others may cause permanent disability or even death of the infant.

When diagnosed and treated early, almost all STDs can be treated effectively. Some organisms, such as certain forms of gonococci, have become resistant to the drugs used to treat them and now require higher doses or newer types of antibiotics. The most serious STD for which no effective treatment or cure now exists is acquired immunodeficiency syndrome (AIDS), a fatal viral infection of the immune system.

Major Types

Diseases that can be transmitted sexually are:

  • Acquired Immunodeficiency Syndrome (AIDS)
  • Bacterial vaginosis
  • Chancroid
  • Chlamydial infections
  • Cytomegalovirus infections
  • Herpes
  • Genital mycoplasma infections
  • Genital (venereal) warts (Papillomavirus)
  • Gonorrhea
  • Granuloma inguinale (Donovanosis)
  • Group B streptococcal infections
  • Molluscum contagiosum
  • Pubic lice
  • Scabies
  • Syphilis
  • Trichomoniasis
  • Enteric infections: Hepatitis A; Amebiasis; Giardiasis; Shigellosis

Papillomavirus (condylomas)

Papillomavirus is a virus that causes growths (called condylomas or genital warts) and it is the most common STD in the U.S. Condylomas commonly accompany other STDs, such as gonorrhea. The virus is usually spread by direct contact with a wart from an infected person.

Condylomas are fleshy growths that appear alone or in clusters. They usually break out in moist areas on or around the genitals (sex organs) and anus. Growths inside the genital organs are soft and red or pink. Outside growths are firm and dark. They are often no larger than the tip of a pencil, but they may combine to form large, cauliflower-like growths.

Genital warts usually appear one to three months after contact, but some go undetected until they cause discomfort. Lesions can become infected and cause mild irritation or itching. Small condylomas may cause rectal pain or pain during intercourse. Papillomavirus may have a serious complication. The presence of condylomas has been linked to cervical cancer. Women with histories of genital warts should have a Pap test at least once a year.