Infection: Chlamydia

Definition

Chlamydia is a sexually transmitted disease (STD) caused by Chlamydia trachomatis bacteria. It is the most commonly reported infectious disease in the United States. Some strains of C. trachomatis can also cause trachoma, an infectious eye disease that can lead to blindness.

Description

C. trachomatis can be transmitted between sexual partners during oral, anal, or vaginal intercourse. It can also be transmitted from an infected mother to her baby during childbirth and cause an eye infection or a type of pneumonia in the newborn. Chlamydia is sometimes called a silent disease, because it may not produce any noticeable symptoms. For women who do feel sick following infection, the most common symptoms are bleeding between menstrual periods, abdominal cramps, pain during intercourse, and a discharge of pus from the vagina. Men may notice inflammation or soreness in their testicles, pain during urination, or a discharge from the penis. One reason why chlamydia is a dangerous disease in spite of the lack of early warning symptoms in many people is that it can lead to long-term complications for men as well as women. Women with untreated chlamydia are at risk of pelvic inflammatory disease (PID), a condition that can cause lifelong infertility. Some infected people are at risk of developing a type of chronic arthritis called Reiter's syndrome.

Demographics

Chlamydia is the most common sexually transmitted disease in the United States. The Centers for Disease Control and Prevention (CDC) estimates that there are as many as 4 million Americans infected with chlamydia, with 2.8 million new infections each year. It is highly likely that the real numbers are higher because many people with chlamydia—75 percent of infected women and 50 percent of infected men—do not have any noticeable symptoms and are not screened by a doctor. The World Health Organization (WHO) estimates that about 89 million people are infected

with chlamydia worldwide, with about 8 million permanently blind as a result of trachoma.

Some groups of people are at greater risk than others of being infected with chlamydia. High-risk groups in the United States include:

• Young adults of either sex
• Adolescent girls between the ages of fifteen and nineteen
• African Americans
• People who have unprotected sex or do not use barrier methods of birth control (condoms or diaphragms)
• Homosexual men, particularly those who are HIV-positive or abuse drugs or alcohol
• People living in large cities
• People with low income or little education
• People who have a large number of sexual partners

Causes and Symptoms

Chlamydia is caused by C. trachomatis, a bacterium that lives inside the cells of the tissues that line the genital tract in both men and women. It can also infect the tissues that line the eye. It takes between one and three weeks for the bacterium to produce noticeable symptoms in infected people; as was noted earlier, however, most infected women and

half of infected men do not develop symptoms troublesome enough to send them to a doctor.

Women infected with chlamydia may notice the following symptoms:

• A burning sensation during urination.
• Pain in the abdomen or lower back
• Fever
• An abnormal discharge from the vagina
• Nausea and vomiting
• Pain during intercourse
• Bleeding between periods

Men infected with chlamydia may experience:

• A burning sensation during urination
• Pain or swelling of the testicles
• A discharge from the penis
• Pain, bleeding, or a discharge from the rectum (in homosexual men)

Diagnosis

Chlamydia is not always diagnosed promptly because so many people who are infected have no symptoms and may not go to a doctor. In May 2007, the American College of Obstetricians and Gynecologists (ACOG) recommended annual screening for chlamydia of all sexually active women age 25 and younger, as well as other women at high risk for infection who do not have symptoms. In addition, many people who do have symptoms of chlamydia are also infected with HIV, gonorrhea, syphilis, or other STDs. It is now common for doctors to test patients for these other diseases to determine which disease is causing the patient's symptoms.

Chlamydia can be diagnosed in both men and women by a simple urine test. Another test that can be used is a laboratory culture of a smear taken from a woman's cervix (the lower end of the uterus), the opening of the urethra at the tip of a man's penis, or the anus.

Treatment

Chlamydia is treated by a course of oral antibiotics, either as a one-time dose or as a series of pills to be taken over a period of five to ten days. People being treated for chlamydia should not have sex for a period of two weeks after treatment to make sure they cannot pass the infection to others.

Prognosis

The prognosis for chlamydia when treated promptly is very good; 95 percent of patients are cured with a single course of antibiotic medications. Between 10 and 40 percent of untreated women, however, will develop pelvic inflammatory disease (PID); of those women who are diagnosed with PID, 5 percent will develop a liver disorder. Reiter's syndrome may also be a long-term or recurrent health problem; more than 40 percent of patients diagnosed with it eventually develop vision problems or permanent arthritis, although they can expect to live normal life spans.

Prevention

Chlamydia can be prevented in several ways:

• Abstaining from sexual intercourse
• Not having sex with high-risk partners
• Using latex condoms every time when having sex
• Avoiding the use of drugs and alcohol, which can impair good judgment
• Having potential sexual partners tested or treated for chlamydia before having sexual relations

Up to one-fourth of patients will be reinfected because their partners were not treated.

WORDS TO KNOW

Pelvic inflammatory disease (PID) : Inflammation of the uterus, fallopian tubes, and ovaries caused by chlamydia or gonorrhea. It can lead to permanent inability to have children if not treated.

Reiter's syndrome : A type of arthritis than can develop in untreated people with chlamydia. It is characterized by inflammation of the genitals and the eyelids as well as sore and aching joints.

Trachoma : An infectious disease of the eye caused by chlamydia bacteria that can lead to blindness if untreated.

The Future

The most important task in fighting chlamydia is the introduction of better screening methods, particularly for young women; more effective tracing and treatment of infected partners; and honest communication between patients and their doctors. As one Boston physician said in

2007, “Discussing sexual activity is not easy for a lot of people, but being honest with your physician and getting tested are imperative for good health and future fertility.”

SEE ALSO AIDS; Gonorrhea; Syphilis

For more information

BOOKS

Breguet, Amy. Chlamydia. New York: Rosen Publishing Group, 2007. Lawton, Sandra Augustyn, ed. Sexual Health Information for Teens. Detroit, MI: Omnigraphics, 2008.

Silverstein, Alvin, Virginia Silverstein, and Amy Silverstein Nunn. The STDsUpdate. Berkeley Heights, NJ: Enslow Elementary, 2006.

PERIODICALS

Altman, Lawrence K. “Sex Infections Found in Quarter of Teenage Girls.” New York Times, March 12, 2008. Available online at http://query.nytimes.com/gst/fullpage.html?res=9507E6D6113BF931A25750C0A96E9C8B63&sec=&spon=&pagewanted=all (accessed May 25, 2008).

American College of Obstetricians and Gynecologists (ACOG) news release. “Spotlight on Chlamydia: Annual Screenings a Must for Young Women.” May 8, 2007. Available online at http://www.acog.org/from_home/publications/press_releases/nr05-08-07-1.cfm (accessed May 27, 2008).

WEB SITES

Centers for Disease Control and Prevention (CDC). Chlamydia: CDC Fact Sheet. Available online at http://www.cdc.gov/std/chlamydia/STDFact-Chlamydia.htm (updated December 20, 2007; accessed May 27, 2008).

National Institute of Allergy and Infectious Diseases (NIAID). Chlamydia. Available online at http://www3.niaid.nih.gov/healthscience/healthtopics/chlamydia/index.htm (accessed May 27, 2008).

TeensHealth. Chlamydia. Available online at http://www.kidshealth.org/teen/infections/stds/std_chlamydia.html (updated April 2006; accessed May 27, 2008).