Chlamydia

Sexually transmitted diseases (STDs) are among the most common infectious diseases in the United States today, affecting more than 13 million men and women annually. Among the more than 20 STDs that have now been identified, chlamydia is the most frequently reported, with an estimated 4 million new cases each year. In Illinois, there were 50,559 cases of chlamydia reported in 2005. Most of these cases--71 percent--occurred among persons 15- to 24-years-old.

What is chlamydia?

Chlamydial infections are caused by a bacterium, Chlamydia trachomatis, and are transmitted during vaginal, oral or anal sexual contact with an infected partner. The National Institute of Allergy and Infectious Diseases estimate that the cost of chlamydial infections and subsequent complications exceeds $2 billion annually.

What are the symptoms?

If symptoms appear at all, it is usually one to three weeks after exposure. Women report vaginal discharge, vaginal bleeding between periods, abdominal pain that is sometimes accompanied by fever and nausea, and burning or pain during urination. Men with the infection report burning or pain during urination and a discharge from the penis.

About three-quarters of infected women and about half of infected men, however, may have no symptoms at all. This is one reason chlamydia is dangerous: Asymptomatic individuals do not seek treatment and therefore can pass the infection on to others. Untreated individuals also can develop complications from the infection.

What kinds of complications can the infection cause?

In women, chlamydia can result in pelvic inflammatory disease (PID), a serious complication that has emerged as a major cause of infertility and ectopic pregnancy among women of childbearing age. The infection also may be passed by a pregnant woman to her newborn baby during delivery, resulting in neonatal eye infection or pneumonia. In men, chlamydial infections can lead to pain or swelling in the scrotum. This can be a sign of epididymitis, an inflammation of a part of the male reproductive system located in the testicles. Both PID and epididymitis can result in infertility.

Other complications include proctitis (inflamed rectum) and conjunctivitis (inflammation of the lining of the eye). A particular strain of chlamydia causes another STD called lymphogranuloma venereum, which is characterized by prominent swelling and inflammation of the lymph nodes in the groin.

Because of the symptoms associated with chlamydia, infected individuals have a three- to five-fold increase in the risk of acquiring HIV (the virus that causes AIDS) if exposed to the virus during sexual intercourse.

To help prevent the serious consequences of chlamydia, screening at least annually for chlamydia is recommended for all sexually active women age 25 years and younger. An annual screening test also is recommended for older women with risk factors for chlamydia (a new sex partner or multiple sex partners). All pregnant women should have a screening test for chlamydia.

How is chlamydia diagnosed?

Until recently, the only way to diagnose chlamydial infection was to take a sample of secretions from the patient's genital area and attempt to grow the organism in a specialized tissue culture in the laboratory. Although this is considered the most definitive test, it is expensive and technically difficult and test results are not available for up to three days.

Several new tests for diagnosing chlamydia have been developed recently. These tests are less expensive and the results are available within two to three days. These new tests detect genetic material from chlamydia and are very accurate. Urine, as well as genital secretions, can be collected as a specimen for these new test methods.

How is chlamydia treated?

Chlamydial infections are treated with a seven-day course of antibiotics, usually doxycycline or erythromycin. A single dose of azithromycin also effectively treats chlamydial infections. Penicillin is not effective against chlamydia.

A person must be sure to take all of the prescribed medication, even if symptoms disappear before taking all the antibiotics. An infected person should refrain from all sexual contact until completing the medication, and it is very important that all sex partners be tested and treated to prevent possible medical complications, reinfection and further spread of the disease.

Women whose sex partners have not been appropriately treated are at high risk for re-infection. Retesting should be considered for women, especially adolescents, three to four months after treatment. This is especially true if a woman does not know if her sex partner received treatment.

How can chlamydia be prevented?

Not having sex is the best protection against chlamydia and other STDs. Having sex with only one uninfected partner who only has sex with you is also safe. The use of latex condoms during sexual intercourse when used consistently and correctly can reduce the risk of transmission of chlamydia. Because chlamydia is highly contagious and yet may cause no symptoms, all men and women who have sexual contact with more than one partner should be tested regularly for the disease. Constant awareness and precautions are necessary because a person who has once contracted the disease does not become immune. Many people acquire chlamydia more than once.

Where can I get more information?

Illinois Department of Public Health
HIV/STD Hotline 800-243-2437 (TTY 800-782-0423)

Centers for Disease Control and Prevention (CDC)
CDC-INFO Hotline (24 hours, 7 days a week)
STD information and referrals to STD Clinics
800-CDC-INFO (800-232-4636)
TTY: 888-232-6348
In English, en Español

CDC National Prevention Information Network (NPIN)
P.O. Box 6003
Rockville, MD 20849-6003
800-458-5231
888-282-7681 Fax
800-243-7012 TTY
E-mail: info@cdcnpin.org

American Social Health Association (ASHA)
P. O. Box 13827
Research Triangle Park, NC 27709-3827
800-783-9877