Office of Women's Health

Facts About Sexually Transmitted Diseases

What are sexually transmitted diseases (STDs)?

Sexually transmitted diseases (STDs) are among the most common infectious diseases in the United States today. More than 20 STDs have been identified and they affect an estimated 19 million men and women in this country each year. The annual treatment cost of STDs in the United States is estimated to be in excess of $14 billion.

How do STDs affect women?

Health problems caused by STDs tend to be more severe and more frequent for women than for men, in part because for women there are often no visible symptoms, so they do not seek care until serious problems have developed.

Some STDs can spread into the uterus (womb) and fallopian tubes to cause pelvic inflammatory disease (PID), which is a cause of both infertility and ectopic (tubal) pregnancy. Ectopic pregnancy can be fatal. STDs in women also may be associated with cervical cancer. Human papillomavirus infection (HPV) can cause genital warts and cervical and other genital cancers. STDs can be passed from a mother to her baby before, during or immediately after birth. Some of these newborn infections can be cured easily, but others may cause a baby to be permanently disabled or even die.

What are the most common types of STDs?

Chlamydial Infection
This infection is the most common of all bacterial STDs, with an estimated 2.8 million new cases occurring each year. Chlamydial infection may cause an abnormal vaginal discharge and burning during urination. In women, untreated chlamydial infection may lead to pelvic inflammatory disease (PID), one of the most common causes of ectopic pregnancy and infertility in women. Many people with chlamydial infection, however, have few or no symptoms of infection; it often goes undiagnosed and untreated. Once diagnosed with chlamydial infection, a person can be treated with an antibiotic.

Genital Herpes
Genital herpes affects at least 45 million Americans ages 12 and older. Approximately 500,000 new cases of this incurable viral infection develop annually. Herpes infections are caused by the herpes simplex viruses type 1 and type 2. Most genital herpes is caused by HSV-2. Most individuals have no or only minimal signs or symptoms. When signs do occur, they typically appear as one or more blisters on or around the genitals or rectum. The blisters break, leaving tender sores that may take two to four weeks to heal the first time they occur. Typically, another outbreak can appear weeks or months after the first, but it almost always is less severe and shorter. The virus remains in the body for life and the lesions may recur from time to time. Severe or frequently recurrent genital herpes is treated with one of several antiviral drugs that are available by prescription. These drugs help control the symptoms, but do not eliminate the herpes virus from the body. Suppressive antiviral therapy can be used to prevent recurrences and perhaps transmission. Women who acquire genital herpes can transmit the virus to their babies during delivery. Untreated HSV infection in newborns can result in mental retardation and death.

Genital Warts
Genital warts (also called venereal warts or condylomata acuminata) are caused by the human papillomavirus, a virus related to the one that causes common skin warts. Certain high-risk types of HPV can cause cervical cancer and other genital cancers, but these are different from the types that cause genital warts. Genital warts usually first appear as small, hard painless bumps in the vaginal area or around the anus. If untreated, they may grow and develop a fleshy, cauliflower-like appearance. There is a very low risk that a pregnant woman with genital warts can pass HPV to her baby. In the rare cases where HPV is passed, the baby could develop warts in the throat or voice box. Genital warts infect between 500,000 to 1 million Americans each year. They are usually removed by freezing, burning or laser treatment. If the warts are very large, they can be removed by surgery. If they recur, they may be treated with injections of a type of interferon. Although treatments may get rid of warts, they do not get rid of HPV, which can still be passed on to sex partners.

Gonorrhea is the second most commonly reported infectious disease in the United States. The CDC estimates that more than 700,000 persons in this country get new gonorrheal infections each year; only about half of these infections are reported to the CDC. Most women who are infected have no symptoms. Even when a woman has symptoms, they can be so non-specific as to be mistaken for a bladder or vaginal infection. The most common symptoms of gonorrhea are a vaginal discharge or vaginal bleeding between periods. Untreated cases can lead to serious complications, including PID, ectopic pregnancy and infertility. Historically, penicillin has been used to treat gonorrhea, but in the last decade resistance to penicillin has emerged. New antibiotics or combinations of drugs must be used to treat these resistant strains.

While the rate of primary and secondary (P&S) syphilis – the most infectious stages of the disease – reached an all-time low in 2000, it has increased dramatically in recent years. Between 2004 and 2005, the number of reported P&S syphilis cases in the United States increased from 7,980 to 8,724. The overall increase in syphilis cases was driven primarily by increases among males. However, troubling trends also were seen among females, as the rate of reported cases among females increased for the first time in more than 10 years. Syphilis is easily curable in its early stages. The initial symptom is a chancre, a painless open sore that usually appears around or in the vagina. If untreated, it can lead to serious long-term complications, including problems of the heart and central nervous system, organ damage and even death. Congenital syphilis can cause stillbirth, death soon after birth, and physical deformity and neurological complications in children who survive. The full course of the disease can take years. Penicillin remains the most effective drug in the treatment of syphilis.

Other STDs
Other diseases that may be sexually transmitted include human immunodeficiency virus (HIV), trichomoniasis, bacterial vaginosis, cytomegalovirus infections and pubic lice (crabs). STDs in pregnant women are associated with a number of adverse outcomes, including spontaneous abortion and infection in the newborn. Low birth weight and prematurity appear to be associated with STDs, including chlamydial infection and trichomoniasis. Congenital or perinatal infection (infection that occurs around the time of birth) occurs in 30 percent to 70 percent of infants born to infected mothers, and complications may include pneumonia, eye infections, and permanent neurologic damage.

What can you do to prevent STDs?

The best way to prevent STDs is to avoid sexual contact with others. If you decide to be sexually active, there are things that you can do to reduce your risk of developing an STD:

  • Have a mutually monogamous sexual relationship with an uninfected partner.
  • Use condoms correctly every time you have sex. The use of latex or polyurethane condoms during vaginal intercourse, when used consistently and correctly, can reduce the risk of transmission of STDs.
  • Delay having sexual relations as long as possible. The younger people are when having sex for the first time, the more susceptible they become to developing an STD. The risk of acquiring an STD also increases with the number of partners over a lifetime.

More information about sexually transmitted diseases can be obtained by contacting:

Illinois Department of Public Health

The Division of STD Prevention, at the Centers for Disease Control and Prevention

CDC-INFO Hotline (24 hours, seven days a week)
800-232-4636 (English and Spanish)
888-232-6348 TTY