Chlamydia

What is chlamydia?

Chlamydia is a curable sexually transmitted disease (STD) caused by the bacteria Chlamydia trachomatis. It is a leading cause of sexually transmitted disease in industrial societies, and of preventable infectious blindness (ocular trachoma) in the developing world. It is also one of the main causes of infertility in humans.

How many people get chlamydia?

According to the Centers for Disease Control and Prevention, chlamydia is the most frequently reported bacterial sexually transmitted disease in the United States, with an estimated 2.8 million people infected annually.

How is chlamydia spread?

Chlamydia can be spread during oral, vaginal or anal sexual contact with an infected partner. In addition, chlamydial infection may affect a newborn baby. A baby who is exposed to C. trachomatis in the birth canal during delivery may develop an eye infection or pneumonia. Symptoms of conjunctivitis (or “pink eye”) usually develop within the first 10 days of life and include discharge and swollen eyelids. Symptoms of pneumonia, such as congestion and a cough that gets steadily worse, most often develop within three to six weeks of birth. Because of these risks to the newborn, many doctors recommend that all pregnant women be tested for chlamydial infection.

Why is chlamydial infection so serious?

Because genital chlamydial infections are asymptomatic in 75 percent of women and 50 percent of men, affected individuals often do not seek appropriate medical care. Left untreated, chlamydia can cause urethral infection and epididymitis in males. In addition, 40 percent of women with untreated chlamydia will develop pelvic inflammatory disease, and 20 percent of these women will become infertile. Pelvic inflammatory disease can also cause scarring of the fallopian tubes, which increases the likelihood of an ectopic pregnancy, a potentially fatal condition in which a fertilized egg develops in the body somewhere other than in the uterus. If chlamydia infection occurs during pregnancy, it can cause adverse outcomes such as premature labor and delivery, as well as conjunctivitis and pneumonia in newborns (see above). Moreover, women infected with chlamydia have a three- to five-fold increased risk of acquiring HIV, if exposed.

What are the symptoms of chlamydia?

Although the majority of cases of chlamydial infection produce no symptoms, those who do have symptoms may experience an abnormal discharge (mucus or pus) from the vagina or penis, or pain during urination. Symptoms usually appear within one to three weeks after being infected. Because the symptoms can be very mild—or nonexistent—many people do not seek care and treatment.

If the infection is not treated, it may move inside the body, where it can cause pink eye, rectum inflammation, and pelvic inflammatory disease in women or epididymitis in men (see above).

How is chlamydia diagnosed?

The most reliable way to diagnose chlamydia infection is through laboratory tests that evaluate a sample of the discharge from the vagina or penis for presence of the chlamydia bacteria.

How can chlamydia be prevented?

Because the majority of chlamydial infections are asymptomatic, the bacteria can be spread to others without knowing it. Using latex condoms consistently and correctly can reduce the chances of getting or spreading chlamydia. Doctors recommend that anyone who has more than one sex partner, especially women under 25 years of age, be tested for chlamydial infection regularly, even if no symptoms are present.

How is chlamydia treated?

When diagnosed, chlamydial infections may be successfully treated with antibiotics such as tetracycline and doxycycline. However, the frequency of C. trachomatis infections has been increasing over the past 20 years. This rise has been attributed in part to the emergence of antibiotic-resistant strains and an increasing population of individuals with weakened immune systems. Moreover, there is no immunity following infection, meaning that individuals may become infected repeatedly. In an effort to improve the diagnosis, treatment and prevention of chlamydial infections, researchers are working to sequence the C. trachomatis genome as well as to develop a safe and effective vaccine.

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