Fast Facts

  • Each year 19 million Americans become infected with an STD. 1
  • Almost half of all new infections occur in young people ages 15-24. 2
  • 1 out of 4 sexually active teenagers will aquire an STD. 3
  • 1 out of 5 Americans under 65 has an incurable STD. 4
  • Most people don’t know they are infected. 5


  1. Centers for Disease Control, “Trends in Reportable Sexually Transmitted Diseases in the United States,” 2005. Retrieved February 2007 from
  2. Ibid.
  3. Alan Guttmacher Institute, Sex and America’s Teenagers. New York: Alan Guttmacher Institute, 1994.
  4. U.S. Department of Health & Human Services, “Progress Review: Sexually Transmitted Diseases,” July 2004. Retrieved February 2007 from
  5., “Talk About Sexually Transmitted Diseases,” n.d.

How do people get STDs?

gloveSTDs are normally transmitted through sexual contact in one of two ways:

  1. Exposure to infected semen, vaginal fluid or blood:
    • Viruses or bacteria in these fluids enter the body through mucosal membranes in the female’s vagina or cervix and the male’s urethra.
    • Examples include HIV, Hepatitis B & C, Gonorrhea, Chlamydia and Trichomoniasis.
  2. Contact with infected skin in genital areas:
    • Genital areas include the penis, vagina, pubic area, inner thighs or anus.
    • A person can be contagious even when no visible symptoms are present. In fact, most people develop no symptoms for a period of time and do not realize they are infected.
    • Infection may result in outbreaks of ulcers (syphilis, chancroid), small red bumps (scabies), blisters (genital herpes) or warts (HPV).
    • Intercourse is not necessary to transmit these infections. They can spread simply through skin-to-skin contact in infected areas.

It is also possible to transmit some STDs without sexual contact. For example, sharing needles is extremely dangerous because it can result in injecting another person’s infected blood particles into your own bloodstream.

Here are some frequently asked questions about STD infection:

Can I get STDs from oral sex?

Yes. Almost all STDs can be transmitted through oral sex. To see a few examples, click here.

Can I get STDs from kissing?

This is possible but not very common. If your partner’s mouth is infected with an STD, then he or she may be able to pass that infection to your mouth during a kiss. Cold sores (oral herpes) can be passed through a kiss if your partner is infected. If your partner has an infection in his or her genital area, then kissing on the mouth will not transmit the infection, and blood-borne infections like HIV or Hepatitis B or C can only be passed through kissing if there is the exchange of infected blood.1

Can I get STDs from a toilet seat?


In the movie Along Came Polly, character Reuben Feffer (Ben Stiller) picked up an STD from a toilet seat. Hollywood hype or the real deal?

Answer: Infection is highly unlikely because the micro-organisms that cause STDs can’t survive outside of the human body for very long. In most cases infection would require a woman’s vagina or a man’s urethra to have direct contact with fresh genital secretions or blood on the toilet seat. Parasites probably have the best chance of infecting someone via contact with a toilet seat. For example, pubic lice can survive for up to 24 hours outside the body, and can even spread through contact with an infected person’s clothes, towels, or bed linens.2

Can babies get STDs from their moms?

Yes. Babies can get STDs from their moms before, during or after birth.3

  • Syphilis and HIV can infect a baby inside a mother’s womb.
  • Gonorrhea, chlamydia and genital herpes can infect a baby as it passes through the birth canal.
  • HIV can infect babies through breastfeeding.

The harmful effects to babies vary. Some children are born dead (stillbirth). Others have complications ranging from eye infection, pneumonia, brain damage, blindness, liver damage, etc.

Doctors frequently perform a C-section (abdominal birth) if they believe there is any risk of a baby becoming infected during a normal, vaginal birth.


  1. American Social Health Association, “Frequently Asked Questions.”
  2. Ibid.
  3. Centers for Disease Control, “STDs and Pregnancy – CDC Fact Sheet.”

Is there a difference between STD & STI?

The Medical Institute provides the following distinction between STD and STI: 1

Although the terms “ sexually transmitted disease (STD) ” and “ sexually transmitted infection (STI) ” are often used interchangeably, they are by no means identical. STI is by far the more inclusive term. Sexually transmitted infection (STI) is an important and scientifically valid term because dangerous pathogenic organisms can be present in the human body without causing disease. It is therefore appropriate to refer to this condition as a sexually transmitted infection.

Sexually transmitted diseases (STDs) result from damage caused by a sexually transmitted infection (STI) that has progressed. Although all STDs are preceded by STIs, not all STIs result in the development of STDs. For instance, about 90% of women who are infected with human papillomavirus clear their infections within two years. Only women with persistent infections are at risk for developing the disease – cervical cancer. It is important to remember that it is not necessary to have a disease, or any symptoms at all, in order to be contagious. Many people who are infected with STIs that have not yet progressed to STDs have gone on to infect other people.


  1. Medical Institute for Sexual Health, “STD and STI: What is the Difference?” October 2004.

Why do we have an STD epidemic?

sexual exposureIn the early 1960’s there were two common STDs in the United States: syphilis and gonorrhea. Today there are over 25. That’s a big change. Why do we have so many STDs today?

The primary reason is that people today have, on average, more sexual partners than they did in the past. 1 The more sexual partners a person has, the greater their chance of catching and spreading STDs. Check out the sexual exposure chart at the left.

[Copyright Heritage House ’76] 2

Former U.S. Surgeon General, C. Everett Koop, said,

” When you have sex with someone, you are having sex with everyone they have had sex with for the last ten years, and everyone they and their partners have had sex with for the last ten years. “


  1. Michael RT, Gagnon JH, Laumann EO, Kolata G. Sex in America: A Definitive Study. Boston, MA: Little Brown and Company; 1994.
  2. This chart represents an average risk of exposure, based on the formula: F(n) = 2n -1 where n is the number of partners.