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Chlamydia

• Chlamydia [kla-MID-ee-uh] is a sexually transmitted bacterial infection.
• Chlamydia can lead to serious reproductive problems, especially in women.
• Chlamydia infection is transmitted through sexual contact with an infected partner. An infected woman can also pass the infection to her newborn during vaginal delivery.
• Chlamydia is often a "silent" infection. Most people with chlamydia have no symptoms and do not seek medical care.
• Once diagnosed, chlamydia is easily cured with antibiotics.
• Prevention centers on 1) use of condoms, and 2) early diagnosis and treatment.

What is chlamydia?

Chlamydia is a sexually transmitted disease (STD) that can lead to serious reproductive problems, especially in women.

What is the infectious agent that causes chlamydia?

Chlamydia is caused by Chlamydia trachomatis, a bacterium.

How do people get chlamydia?

Chlamydia is spread by having vaginal sex with a person who has the infection. It can also be passed from an infected mother to her newborn during vaginal childbirth.

What are the signs and symptoms of chlamydia?

Chlamydia is known as a "silent" disease because three quarters of the women and half of the men infected with the bacterium have no symptoms. Thus, the infection can become very serious before a person even recognizes a problem.

Symptoms in men: Men with symptoms might have a discharge from the penis and a burning sensation when urinating. Men might also have burning and itching around the opening of the penis and/or pain and swelling in the testicles.

Symptoms in women: The few women with symptoms might have a vaginal discharge or a burning sensation when urinating. When the infection spreads to the uterus and fallopian tubes, women can have lower abdominal pain, nausea, fever, pain during intercourse, and bleeding between menstrual periods.

How soon after exposure do symptoms appear?

If symptoms do occur, they usually appear within 1 to 3 weeks of exposure.

How is chlamydia diagnosed?

There are two kinds of laboratory tests to diagnose chlamydia. One involves collecting a small amount of fluid from an infected site (cervix or penis) to detect the bacterium directly. New tests use urine samples to detect small pieces of chlamydia nucleic acid. These are not yet widely available but are making testing much easier, faster, and less painful.

Who is at risk for chlamydia?

Sexually active men and women can be exposed to chlamydia bacteria unknowingly via sexual contact with an infected person. The more sex partners a persons has, the greater the risk of chlamydia infection. Babies born to infected mothers are also at risk.

Sexually active teenagers and young women are especially susceptible to chlamydia bacteria because of the characteristics of the cells that form the inner lining of the cervix. These cells are easily invaded by chlamydia bacteria. In young women, they are exposed on the outer part of the cervix, making them more vulnerable. The cells eventually recede inside the cervix as a woman matures.

What is the treatment for chlamydia?

Chlamydia can be treated and cured with antibiotics. A single dose of azithromycin or a week of doxycycline (twice daily) are the most commonly used treatments. All sex partners must also be treated.

What complications can result from chlamydia?

Untreated, chlamydia infection can progress to serious reproductive and other health problems with both short-term and long-term consequences. Like the disease itself, the damage that chlamydia causes is often "silent."

Untreated chlamydia in men typically causes urethral infection. Infection sometimes spreads to the epididymis (a tube that carries sperm from the testis), causing pain, fever, and potentially infertility.

In women, chlamydia usually begins in the cervix. If not treated, it can spread to the fallopian tubes and cause an infection called pelvic inflammatory disease (PID). PID can cause chronic pelvic pain, infertility, and potentially fatal ectopic pregnancy (pregnancy outside the uterus). In pregnant women, there is some evidence that chlamydia infections can lead to premature delivery.

Babies who are born when their mothers are infected can get chlamydia infections in their eyes and respiratory tracts. Chlamydia is the leading cause of early infant pneumonia and conjunctivitis (pinkeye) in newborns.

How common is chlamydia?

Chlamydia is the most frequently reported infectious disease in the United States. More than 450,000 cases were reported in 1995. Under-reporting is substantial, though, because most people with chlamydia are not aware of their infections. An estimated 4 million Americans are believed to have it, mostly teenage girls.

Is chlamydia an emerging infectious disease?

Chlamydia is a very common condition in the United States. From 1984 through 1995, reported rates increased from 3.2 to 182.2 cases per 100,000 people. This trend mainly reflects increased screening, increased recognition of symptom-less infections (mainly in women), and improved reporting.

How can chlamydia be prevented?

• Young, sexually active and unmarried persons should be screened for chlamydia yearly.
• Anyone with symptoms should get medical advice, evaluation, and treatment right away.
• Anyone found to be infected should inform all sex partners and be sure they get treated, too.
• Persons being treated for chlamydia infection should not have sex of any kind until treatment is completed as directed for all partners.
• Persons being treated must complete all medications. They should not stop taking prescribed medicines when symptoms disappear.

As a general rule: Sexually active women and men should always use a barrier form of contraception, such as a latex condom. Birth control pills do not protect women from chlamydia.

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above or think that you might have a sexually transmitted infection, consult a health-care provider.

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