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A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M.; 2013.

A.D.A.M. Medical Encyclopedia.

Chlamydia

Last reviewed: May 31, 2012.

Chlamydia is an infection caused by the bacteria Chlamydia trachomatis. It is most commonly sexually transmitted.

Causes

Chlamydia infection is the most common sexually transmitted infection in the United States. Sexually active individuals and individuals with multiple partners are at highest risk.

Symptoms

As many as 25% of  men with chlamydia have no symptoms. In men, chlamydia may produce symptoms similar to gonorrhea. Symptoms may include:

About 70% of women with chlamydia have no symptoms. Symptoms that may occur in women include:

See also: Chlamydia in women

Exams and Tests

The diagnosis of chlamydia infection involves sampling of the urethral discharge in males or cervical secretions in females. If an individual engages in anal sexual contact, samples from the rectum may also be needed. The sample is sent for a fluorescent or monoclonal antibody test, DNA probe test, or cell culture. Some of these tests may also be performed on urine samples.

Treatment

The usual treatment for chlamydia is antibiotics, including tetracyclines, azithromycin, or erythromycin.

You can get chlamydia with gonorrhea or syphilis, so if you have one sexually transmitted infection you must be screened for other sexually transmitted infections as well. All sexual contacts should be screened for chlamydia.

Sexual partners must be treated to prevent passing the infection back and forth. There is no significant immunity following the infection and a person may become repeatedly infected.

A follow-up evaluation may be done in 4 weeks to determine if the infection has been cured.

Outlook (Prognosis)

Early antibiotic treatment is extremely successful and may prevent the development of long-term complications. Untreated infection, however, may lead to complications.

Possible Complications

Chlamydia infections in women may lead to inflammation of the cervix. In men, chlamydia infection can lead to inflammation of the urethra called urethritis.

An untreated chlamydia infection may spread to the uterus or the fallopian tubes, causing salpingitis or pelvic inflammatory disease. These conditions can lead to infertility and increase the risk of ectopic pregnancy.

If a women is infected with chlamydia while pregnant, the infection may cause infection in the uterus after delivery (late postpartum endometritis). In addition, the infant may develop chlamydia-related conjunctivitis (eye infection) and pneumonia. See: chlamydial pneumonia

When to Contact a Medical Professional

Call your health care provider if you have symptoms of chlamydia.

Because many people with chlamydia may not have symptoms, sexually active adults should be screened periodically for the infection.

Prevention

All sexually active women up through age 25 should be screened yearly for chlamydia. All women with new sexual partners or multiple partners should also be screened.

A mutually monogamous sexual relationship with an uninfected partner is one way to avoid this infection. The proper use of condoms during intercourse usually prevents infection.

References

  1. U.S. Preventive Services Task Force. Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2007;147:128-134. [PubMed: 17576996]
  2. Geisler WM. Diseases caused by chlamydiae. In: Goldman L, Shafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 326.
  3. Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines. 2010 MMWR. 2010;59(RR-12):1-110. [PubMed: 21160459]

Review Date: 5/31/2012.

Reviewed by: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

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The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

What works?

  • Interventions for treating genital chlamydia trachomatis infection in pregnancyInterventions for treating genital chlamydia trachomatis infection in pregnancy
    Chlamydia is a sexually transmitted infection which, if a mother has it during pregnancy and labour, can cause eye or lung infections in the newborn baby. The risk of transmission during birth varies, but is about 20% to 50% for eye infections and about 10% to 20% for infection of the lungs. Mothers may also be at increased risk of infection of the uterus. The review looked at various antibiotics being used during pregnancy to reduce these problems and to assess any adverse effects. Tetracyclines taken in pregnancy are known to be associated with teeth and bone abnormalities in babies, and some women find erythromycin unpleasant to take because of feeling sick and vomiting. The review found eleven trials, involving 1449 women, on erythromycin, amoxycillin, azithromycin and clindamycin, and the overall trial quality was good. However, all the trials assessed 'microbiological cure' (that is they looked for an eradication of the infection) and none assessed whether the eye or lung problems for the baby were reduced. Also, none of the trials were large enough to assess potential adverse outcomes adequately. The review found amoxycillin was an effective alternative to erythromycin but lack of long‐term assessment of outcomes caused concern about its routine use in practice. If erythromycin is used, some women may stop taking it because of adverse effects. Azithromycin and clindamycin are potential alternatives. More research is needed.
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