The Truth About STDs
There are more than 25 diseases spread primarily by sexual activity. Together these infections -- called sexually transmitted diseases (STDs) -- have created a significant public health challenge in the United States. While many STDs are curable, others are not. Even those that are curable often have no symptoms and go unrecognized for long periods of time. If left untreated, even curable STDs can result in long-term health problems for both men and women.
In the United States, an estimated 15 million people become infected with one or more STDs each year. In addition, an estimated 65 million people live with an incurable STD. Still, less than half of adults 18 to 44 years of age have ever been tested for an STD other than HIV/AIDS.1 This fact sheet is designed to provide health care professionals, educators, and individuals with basic information. It focuses on eight of the most common STDs and contains information on how they are spread, what signs and symptoms individuals should look for, and what treatment options are available. Those interested in learning more about these or other STDs can go the web site of the Centers for Disease Control and Prevention at www.cdc.gov/nchstp/dstd/disease_info.htm.
Note: Some professionals use the term sexually transmitted infection (STI) instead of sexually transmitted disease (STD). This fact sheet uses the term STD.
|Two STD Categories: Viral and Bacterial|
STDs are often divided into two categories -- viral and bacterial -- based on the type of microorganism that causes the specific disease.
Those STDs caused by bacteria -- such as gonorrhea, syphilis, and chlamydia -- are curable with antibiotics. On the other hand, those STDs caused by viruses are not curable. These include human immunodeficiency virus (HIV), human papillomavirus (HPV), herpes, and hepatitis B. Medical treatment can, however, alleviate the symptoms of these STDs.
Some STDs are also caused by protozoa (trichomoniasis) and other organisms (crabs/pubic lice and scabies). These STDs are curable with antibiotics or topical creams/lotions.
|Testing for STDs: What's Involved|
Less than half of adults 18 to 44 years of age in the United States have been tested for an STD other than HIV. Some people may not seek a test because they do not know they are at risk. Others may not seek a test because they are nervous, embarrassed, or unsure of what the tests involve.
There are many different ways health care providers screen for STDs. These can include visually examining sores or lesions, collecting fluid from the urethra or cervix with a cotton swab, testing urine or blood, or conducting a biopsy.
Individuals should seek an early diagnosis and treatment at the first sign of symptoms to avoid serious complications. They should also talk to their health care providers about having a routine STD screening as part of their annual physical or gynecological exam since many STDs have no symptoms. Women need to understand that STD screenings are not necessarily part of their annual gynecological exam and that Pap smears do not screen for STDs other than HPV.1
Chlamydia, which is caused by the bacteria chlamydia trachomatis, targets the cells of mucous membranes including the surfaces of the urethra (male and female), vagina, cervix, and endometrium (the lining of the uterus) as well as the anus and rectum. Although possible, it rarely targets the mouth or throat. If left untreated in women, it can spread to the fallopian tubes and lead to Pelvic Inflammatory Disease (PID), a serious medical condition that can cause infertility.2
Chlamydia is transmitted through vaginal or cervical secretions and semen during unprotected anal, oral, or vaginal sex with an infected person. It can also be transmitted from mother to newborn during childbirth.3
Chlamydia is not transmitted through such casual contact as hugging, shaking hands, sharing food, using the same eating utensils, drinking from the same glass, sitting on public toilets, or touching door knobs.4
Signs and Symptoms5
- Signs of infection usually appear within one to three weeks after contact. In some cases, infection is obvious only after several weeks or months. Approximately 75 percent of women and 50 percent of men do not have symptoms.
- Women may experience such symptoms as itching, vaginal discharge, and burning during urination.
- Some women may experience pain of the lower abdomen or back, pain during intercourse, bleeding between menstrual periods, nausea, or fever if the infection has spread to the fallopian tubes. This may indicate that the infection has progressed to PID.
- Men may experience heaviness and discomfort in their testicles and inflammation of their scrotal skin. They may also notice pus in the form of a thick white fluid or watery or milky discharge from the penis. Men may also experience pain or burning during urination.
Chlamydia is diagnosed through cultures of secretions collected from the urethra, anus, throat, or cervix. It is also diagnosed through urine tests.
Chlamydia is curable with oral antibiotics prescribed by a health care provider. All partners should undergo treatment at the same time to avoid passing the infection back and forth. They should also be sure to finish the full course of antibiotics even if symptoms subside.
Gonorrhea, once known as "the clap," is caused by bacteria called Neisseria gonorrhoea that grow in the warm, moist areas of the reproductive tract, including the cervix, uterus, and fallopian tubes in women and the urethra in both women and men. The bacteria can also grow in the mouth, throat, and anus.7
Gonorrhea is transmitted through vaginal or cervical secretions and semen during unprotected anal, oral, or vaginal sex with an infected person. It can also be transmitted from mother to newborn during childbirth.
Gonorrhea is not transmitted through such casual contact as hugging, shaking hands, sharing food, using the same eating utensils, drinking from the same glass, sitting on public toilets, or touching door knobs.8
Signs and Symptoms9
- Most men and women will experience no symptoms.
- Men may show signs of infection within two to five days after exposure. Women may show signs within 10 days. The signs are similar to those of chlamydia. Individuals should, therefore, receive tests for both STDs.
- Men may experience such symptoms as a yellowish discharge from the penis, burning or pain during urination, frequent urination, and pain or swelling of the testicles.
- Women may experience such symptoms as a yellow or bloody discharge from the vagina and burning or pain during urination.
- Some women may experience pain of the lower abdomen or back, pain during intercourse, bleeding between menstrual periods, and nausea or fever if the disease has spread to the fallopian tubes. This is often an indication that the infection has progressed to PID.
- Men and women may have a sore or red throat if the infection has spread to that part of the body.
Gonorrhea is diagnosed through cultures of secretions collected from the throat, urethra, anus, or cervix. It is also diagnosed through urine tests.10
Gonorrhea is curable with oral antibiotics prescribed by a health care provider. All partners should undergo treatment at the same time to prevent passing the infection back and forth. They should also be sure to finish the full course of antibiotics even if symptoms subside.
Syphilis, which is caused by bacteria called spirochetes, causes sores (chancres) to appear mainly on the external genitals, vagina, anus, or in the rectum. They can also appear on the lips and in the mouth.
There are three stages of syphilis. During the primary stage, which usually occurs within 10 to 90 days after exposure, a sore may appear. During the secondary phase, which usually occurs within 17 days to six-and-a-half months after exposure, a rash may appear on various parts of the body. If left untreated, syphilis can proceed to the latent stage during which it may have no visible symptoms but can cause irreversible damage to internal organs.11
Syphilis is transmitted through direct contact with sores during unprotected anal, oral, or vaginal sex with an infected person. Syphilis can also be transmitted from mother to newborn during childbirth.12
Syphilis is not transmitted through such casual contact as hugging, shaking hands, sharing food, using the same eating utensils, drinking from the same glass, sitting on public toilets, or touching door knobs.13
Signs and Symptoms
- Women and men may experience the same signs of syphilis.
- During the "primary" stage, a sore may appear on the genitals at or near the place where the bacteria entered the body. Usually firm, round, small, and painless, the sore will develop within 10 to 90 days after contact with the bacteria and will usually last from one to five weeks. A person can easily spread the disease during this stage. If adequate treatment is not received, the infection will progress to the "secondary" stage.14
- During the "secondary" stage, a rash may appear over the entire body or on the hands and soles of the feet. Other symptoms may include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and tiredness. Symptoms may appear from 17 days to six-and-a-half months after infection has occurred. They can last up to six months. A person can easily spread the disease during this stage. If adequate treatment is not received, the infection will progress to the "latent" stage.15
- During the "latent" stage, the untreated bacteria will begin to damage internal organs, including the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints. Latent signs may include uncoordinated muscle movements, paralysis, numbness, gradual blindness, and dementia. A person is not usually contagious during this stage.16
Syphilis is diagnosed through cultures of secretions from the sore or through blood tests.17
Syphilis is curable with antibiotics prescribed by a health care provider. Damage to internal organs during the latent stage is irreversible. All partners should undergo treatment at the same time to prevent passing the infection back and forth. They should also be sure to finish the full course of antibiotics even if symptoms subside.
|CDC'S National Syphilis Elimination Plan|
As the result of a steady decline in syphilis rates in the United States, the CDC launched a National Plan to Eliminate Syphilis From the United States in 1998.
The CDC is using this window of opportunity to reduce the total number of primary and secondary syphilis cases to 1,000 or fewer -- 0.4 cases per 100,000 people -- and to increase the number of syphilis-free counties to 90 percent by 2005.
The National Plan has five strategies: (1) to increase surveillance, (2) to strengthen community involvement and partnerships, (3) to rapidly respond to outbreaks, (4) to improve and increase health promotion, and (5) to expand clinical and laboratory services.
Trichomoniasis, or "trich," is a genital inflammation caused by the protozoa trichomonas vaginalis.
Trichomoniasis is transmitted through skin-to-skin contact during unprotected anal, oral, or vaginal sex with an infected person.18
Signs and Symptoms19
- Signs of infection in women usually appear within five to 28 days after exposure. Men usually show no signs of infection.
- Women may have a frothy, yellow-green vaginal discharge with a strong odor. They may also experience burning during intercourse and urination as well as irritation and itching of the female genital area.
- Pregnant women may experience a premature rupture of the membranes and a preterm delivery.
- Men may experience irritation inside the penis, a mild discharge, or a slight burning after urination or ejaculation.
Trichomoniasis is diagnosed through cultures of vaginal and penile discharge.20
Trichomoniasis is curable with antibiotics prescribed by a health care provider. Both partners must undergo treatment at the same time to prevent passing the infection back and forth. They should also be sure to finish the full course of antibiotics even if symptoms subside.
Herpes is a recurrent skin condition characterized by sores on the mouth or genitals. It is caused by the herpes simplex viruses called HSV-1 and HSV-2. Although HSV-1 most commonly causes "cold sores" or "fever blisters" on the mouth or face and HSV-2 most commonly causes sores on the penis or vulva, the viruses are identical under a microscope and either type can infect the mouth or genitals.21
Herpes is transmitted through skin-to-skin contact during unprotected anal, oral, or vaginal sex with an infected person or through kissing. This is possible even when no sores are present.
Herpes is not transmitted through such casual contact as hugging, shaking hands, sharing food, using the same eating utensils, drinking from the same glass, sitting on public toilets, or touching door knobs.22
Signs and Symptoms
- Individuals are often not aware they are infected with herpes because there are either no symptoms, mild symptoms that are not noticed, or symptoms that are mistaken for other health problems such as yeast infections, insect bites, and hemorrhoids.
- Signs of herpes may first appear within days. They may, however, not appear for weeks, months, or years. Symptoms can last for three or four weeks though they usually heal within two to 12 days.23
- Symptoms may include one or more sores, blisters, cuts, pimples, bumps, or a rash. Other symptoms include an itching, burning, or tingling in either the genital area or the mouth, a fever, or swollen glands.24
- Individuals usually have an average of four to five herpes outbreaks a year. The recurrences tend to lessen in severity and frequency with time.25
Herpes is diagnosed through a visual examination of sores, an analysis of cultures from the sore(s), or blood tests.26
There is no cure for herpes. Antiviral medications can reduce the frequency of outbreaks and speed the healing of the outbreaks.
Hepatitis B is a virus that causes chronic infection, cirrhosis (scarring), and cancer of the liver. The virus is present in blood, semen, vaginal secretions, and breast milk.
Hepatitis B is transmitted through unprotected anal, vaginal, and oral sex with an infected person; through contaminated needles or syringes; or from an infected mother to her newborn during childbirth or breast-feeding.
Hepatitis B is the only STD for which a vaccine is available. Individuals must take all three doses of the vaccine to protect themselves against infection. They can obtain the vaccine from their health care provider.27
Hepatitis B is not transmitted through such casual contact as hugging, shaking hands, sharing food, using the same eating utensils, drinking from the same glass, sitting on public toilets, or touching door knobs.28
Signs and Symptoms
- Individuals will usually experience mild flu-like symptoms including fever, aches, appetite loss, and fatigue. Many people will experience no symptoms.29
- Many people will develop a temporary jaundice (yellowing of the skin) as well as dark urine, nausea, and abdominal pain.30
Hepatitis B is diagnosed through blood tests.31
There is no cure for hepatitis B. Treatment varies depending on whether the infection is acute (newly acquired) or chronic (persistent).32
Human Immunodeficiency Virus
The human immunodeficiency virus (HIV) causes an individual's immune system to weaken and lose its ability to fight off infections and cancers. After developing a number of these infections or reaching a certain blood count level, an HIV-positive person is diagnosed with Acquired Immunodeficiency Syndrome (AIDS).33
HIV is present in blood, semen, vaginal secretions, and breast milk. It is transmitted through unprotected anal, vaginal, and oral sex with an infected person; through contaminated needles or syringes used to inject drugs; or from an infected mother to her newborn during childbirth or breast-feeding.34
HIV is not transmitted through such casual contact as hugging, shaking hands, sharing food, using the same eating utensils, drinking from the same glass, sitting on public toilets, or touching door knobs.35
Signs and Symptoms
- There are no symptoms of HIV infection.
- The average time between HIV infection and AIDS is eight to 11 years.
- Over time, HIV causes the body to develop opportunistic infections or cancers normally controlled by a healthy immune system.
- AIDS symptoms are usually those of the opportunistic infection or cancer. These include fever, chills and sweats, chronic fatigue, appetite or weight loss, muscle and joint pain, long-lasting sore throat, swollen lymph nodes, diarrhea, yeast infections, and skin sores.
- Opportunistic infections that most frequently affect someone with AIDS include Kaposi's sarcoma, Pneumocystis carinii pneumonia (PCP), tuberculosis, meningitis, and herpes simplex infections.
HIV infection is diagnosed through blood tests. It can also be diagnosed through urine tests and an oral fluid test taken from the inside of the mouth.36 Individuals exposed to HIV may not test positive for three to six months. Individuals should test periodically for HIV if they feel they are at risk.
There is no cure or vaccine for HIV or AIDS. There are, however, new combinations of drugs (called "cocktails") that allow people to live with the infection or HIV/AIDS for longer periods of time.
Tests that determine HIV infection look for antibodies produced by the body to fight the virus. Most people will develop such antibodies between 25 days and six months after infection. Although it is possible to test earlier, the CDC recommends testing six months after the last possible exposure.
Many places provide testing for HIV infection. These include local health departments, doctors' offices, hospitals, or specific HIV test sites.
Sites may provide pre- and post-test counseling for those who want it. They may also provide either anonymous (no name given) or confidential (name given only to doctor) testing. Some states require that doctors report positive results to state health departments. Individuals should check to determine procedures at individual sites.
Most HIV tests involve drawing blood to determine if antibodies specific to HIV are present. Other options include urine tests and oral fluid tests that involve taking a sample of fluid from inside the mouth with a cotton swab.
For more information about HIV tests and test sites, individuals should contact the CDC National AIDS Hotline at 1-800-CDC-INFO (English) or 1-8888-232-6348 (TTY).
There are over 100 strains of the human papillomavirus (HPV). Approximately a third of these strains cause warts that infect the genital tract. These warts can grow on the cervix, vagina, vulva, penis, scrotum, urethra, and anus. HPV can also cause other abnormal cells to grow on the cervix. Some strains of HPV can lead to cervical cancer.37
HPV is transmitted by direct skin-to-skin contact with an infected individual. It can also transmitted when warts are not present.38 It is sometimes transmitted from mother to infant during childbirth.39
Signs and Symptoms40
- People with HPV may experience no visible signs or symptoms or may have warts in places they cannot see (such as the cervix).
- Genital warts are raised or flat growths that are usually flesh colored or whitish in appearance.
- Genital warts usually do not cause itching or burning.
- If left untreated, genital warts may disappear. However, HPV infection remains and warts can reappear.
HPV is often diagnosed through a visual examination of genital warts. In some cases, a biopsy is necessary.
The presence of HPV on the cervix is detected through a Pap smear.41
There is no cure for HPV. There are, however, a number of methods to remove warts.
|HPV and Cervical Cancer|
Certain strains of HPV are considered the primary risk factor for cervical cancer. The majority of such cancers develop through a series of gradual precancerous lesions that are easily detected by a Pap smear, and can be removed.1
A Pap smear is a routine gynecological test in which a health care provider uses a cotton swab or similar instrument to collect cells from the cervix. The test looks for abnormal or precancerous cells. These cells may be signs of cervical cancer.2
Regular Pap smears reduce the risk of invasive cervical cancer by early detection of abnormal cells. In fact, over half of women with newly diagnosed cervical cancer had not had a Pap smear in five years.3
Researchers are developing a vaccine that targets HPV-16, one of the HPV strains that lead to cervical cancer. In initial trials, none of the women who received the vaccine showed HPV-16 infections or precancerous tissue. The vaccine is awaiting approval by the Food and Drug Administration (FDA).4
It is important to note that not every HPV infection will become cervical cancer. The National Cancer Institute points out that while HPV infection is common, cervical cancer is not.5
- P. Guthrie, "Vaccine Could Wipe Out Cervical Cancer; Study: New Drug 100% Effective against Disease," The Atlanta Journal and Constitution, November 21, 2002.
|Condoms and STDs: Prevention Messages|
Condoms can provide different levels of risk reduction for different STDs. There is no definitive study about condom effectiveness for all STDs. Definitive data are lacking on the degree of risk reduction that latex condoms provide for some STDs; for others, the evidence is considered inconclusive.
The Centers for Disease Control and Prevention (CDC) states, "It is important to note that the lack of data about the level of condom effectiveness indicates that more research is needed -- not that latex condoms do not work."1
These are prevention messages recently developed by the CDC:
- Latex condoms, when used consistently and correctly, are highly effective in preventing the transmission of HIV, the virus that causes AIDS. In addition, correct and consistent use of latex condoms can reduce the risk of other STDs.
- Latex condoms, when used consistently and correctly, can reduce the risk of transmission of gonorrhea, chlamydia, and trichomoniasis.
- Latex condoms, when used consistently and correctly, can reduce the risk of genital herpes, syphilis, and HPV only when the infected areas are covered or protected by the condom.2
- U.S. Centers for Disease Control and Prevention (CDC), Latex Condoms and Sexually Transmitted Diseases -- Prevention Messages (Atlanta, GA: CDC, 2001), p. 2.
|Update on Nonoxynol-9|
In the past, public health experts recommended using condoms combined with Nonoxynol-9 (N-9), a spermicide, for increased protection against pregnancy, HIV, and STDs. Two recent studies, however, call into question the effectiveness and safety of N-9.
A study published by UNAIDS found that N-9 used without condoms was ineffective against HIV transmission. This study actually showed some evidence that N-9 increased the risk of HIV infection.
Researchers note that this study was conducted among commercial sex workers in Africa who are at increased risk and used an N-9 gel on a frequent basis. The adverse effects might not be seen at the same level among women who are using N-9 less frequently or in a different formulation.
As a result of this study, however, the CDC concluded that "given that N-9 has been proven ineffective against HIV transmission, the possibility of risk, with no benefit, indicates that N-9 should not be recommended as an effective means of HIV prevention."1
A similar study published in the Journal of the American Medical Association found that N-9, when used with condoms, did not protect women from the bacteria that cause gonorrhea and chlamydia any better than condoms used alone.2
- Letter to Colleagues from Helene D. Gayle, M.D., M.P.H., director, National Center for HIV, STD, and TB Prevention, U.S. Centers for Disease Control and Prevention, August 4, 2000.
- R. E. Roddy, L. Zekeng, K. A. Ryan, U. Tamoufé, and K. G. Tweedy, "Effect of Nonoxynol-9 Gel on Urogenital Gonorrhea and Chlamydial Infection: A Randomized Controlled Trial," Journal of the American Medical Association, March 6, 2002, pp. 1117-22.
Incidence and Prevalence
People with STDs do not always seek testing or treatment, and health care providers do not always report all cases of diagnosed STDs. Therefore, in all likelihood, the number of STD cases included in the following statistics is less than the actual number of cases that occurred in the United States.
- Over 783,000 chlamydia infections were reported to the CDC in 2001.42
- The reported rate of chlamydia among women (435.2 cases per 100,000 females) was approximately four times higher than the reported rate among men (113.9 per 100,000 males) in 2001.43
- Female adolescents 15 to 19 years of age had the highest reported rates of chlamydia (2,536.1 per 100,000) in 2001.44
- Chlamydia infections increased from 50.8 to 278.3 per 100,000 between 1987 and 2001.45
- Over 361,000 cases of gonorrhea were reported to the CDC in 2001.
- The reported rate of gonorrhea among women in 2001 (128.2 cases per 100,000 females) was similar to the rate in 2000 (126.7 per 100,000) and in 1999 (128.6 per 100,000).
- The rate of gonorrhea among men declined from 135.5 cases per 100,000 males in 1999 to 130.9 in 2000 and 128.2 in 2001.
- Among women, those 15 to 19 years of age had the highest reported rate of gonorrhea (703.2 per 100,000) in 2001.
- Among men, those 20 to 24 years of age had the highest reported rate of gonorrhea (563.6 per 100,000) in 2001.
- Over 6,100 cases of primary and secondary syphilis cases were reported to the CDC in 2001.
- The reported rate of primary and secondary syphilis increased 15.4 percent among men (from 2.6 cases to 3.0 cases per 100,000) between 2000 and 2001. During this time, the rate declined 17.7 percent among women (from 1.7 to 1.4 cases per 100,000).
- Approximately 25 percent of adults have genital herpes.
- Over 45 million people 12 years of age and older (or one out of five) are infected with HSV-2, a herpes virus.
- Infection with HSV-2, a herpes virus, is more common in women (approximately one out of four) than in men (almost one out of five). This may be due to the fact that male-to-female transmission is more efficient than female-to-male transmission.
- The number of new hepatitis B infections per year has declined from an average of 260,000 in the 1980s to approximately 78,000 in 2001.49
- Of an estimated 1.25 million Americans chronically infected with hepatitis B, 20 to 30 percent were infected during childhood.50
Human Immunodeficiency Virus (HIV)
- Nearly 24,000 adult and adolescent males from the 39 areas of the country with confidential HIV-infection reporting were diagnosed as HIV positive in 2001.51
- Over 11,000 adult and adolescent females from the 39 areas of the country with confidential HIV-infection reporting were diagnosed as HIV positive in 2001.52
- Nearly 32,000 adult and adolescent males were diagnosed with AIDS in 2001. In total, over 666,000 cases among adult and adolescent males were reported through December 2001.53
- Over 11,000 adult and adolescent females were diagnosed with AIDS in 2001. In total, over 141,000 cases among adult and adolescent females were reported through December 2001.54
Human Papillomavirus (HPV)
- Approximately 5.5 million new cases of HPV infection are reported every year. At least 20 million Americans are already infected.55
- Fifty to 75 percent of sexually active men and women will become infected with genital HPV at some point in their lives.56
- Approximately 14,000 women are diagnosed with cervical cancer each year; over 5,000 die from this disease each year.57
|STDs Among Adolescents and Young Adults|
Teens are at high behavioral risk for acquiring most STDs. Teens and young adults are more likely than other age groups to have multiple sex partners and to engage in unprotected sex. In addition, young women are biologically more susceptible to chlamydia, gonorrhea, and HIV.
Chlamydia and gonorrhea are the most common curable STDs among teens. Curable STDs are typically caused by bacteria that can be killed with antibiotics. However, if these diseases remain undetected and untreated, they can result in severe health consequences later in life.
The rate of new infections for herpes and HPV -- both viral STDs -- is typically highest during the late teens and early twenties. Among women under the age of 25, studies have found that 28 to 46 percent are typically infected with HPV. Between 15 to 20 percent of young men and women have become infected with herpes by the time they reach adulthood.
- Tracking the Hidden Epidemics: Trends in STDs in the United States, 2000 (Atlanta, GA: Centers for Disease Control and Prevention, 2001), p. 4.
- The Boston Women's Health Book Collective, Our Bodies, Ourselves: For the New Century, (New York: Touchstone, 1998), p. 355.
- Sexually Transmitted Disease Surveillance 2001 (Atlanta, GA: Division of STD Prevention, CDC, September 2002), p. 7.
- Ibid, p. 8
- Ibid, p. 7
- Ibid, p. 15, 16
- Ibid., p. 25, 26
- HIV Surveillance Report, vol. 13, no. 2 (Atlanta, GA: CDC, December 2001), p. 19, Table 10.
- Ibid., p. 21, Table 12.
- Ibid., p. 18, Table 9.
- Ibid., p. 20, Table 11.