Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

Chlamydia

Pronounced: kluh-MID-ee-uh
by Michelle Badash, MS
Definition

Chlamydia is a bacterial infection. It is a sexually transmitted disease (STD). In fact, it is one of the most common STDs in the United States. Chlamydia has become more common since the 1990s. It is most common among sexually active teens and young adults.

Causes

This infection is caused by bacteria known as Chlamydia trachomatis . It is passed from an infected partner during sex. This can happen during oral, vaginal, or anal sex.

Risk Factors

Factors that increase your chance of chlamydia include:

  • Having sex without a condom
  • Age: 15-25 years old
  • History of sexually transmitted diseases
  • Multiple sex partners
Symptoms

It is possible to have this infection and have no symptoms. Many people do not know they are infected. If symptoms do occur, they usually appear within 1-3 weeks of exposure.

Symptoms include:

In Men:
  • Painful sensation while urinating
  • White or clear discharge from the penis
In Women:
  • Abdominal pain
  • Increased or abnormal vaginal discharge
  • Pain or bleeding during or after sex
  • Painful urination
  • Unusual vaginal bleeding

Pregnant women can also pass chlamydia to their newborns. This can happen during birth. It may cause conjunctivitis or pneumonia in the baby. Testing during pregnancy and treatment if the test shows chlamydia can greatly reduce risk to the baby.

Diagnosis

The symptoms can be very similar to another STD, gonorrhea . Your doctor will look for the specific bacteria. A swab test from the discharge of the penis or the cervix may be done. It is the most reliable method of detection for this bacteria. A urine sample may also be used. You may also be tested for others STDs, including HIV .

Treatment

This infection is treated with antibiotics. The most commonly prescribed antibiotics are:

  • Azithromycin (eg, Zithromax, Zmax)
  • Doxycycline (eg, Vibramycin and others)

It is important that you and your partner both be treated before you have sex again. All of the medicine must be taken as directed. If you still have symptoms after the medicine is finished, you may need to be tested again.

Untreated chlamydia can have serious results:

In Men:
  • Joints—inflammation of the joints ( Reiter's syndrome )
  • Prostate—inflammation of the prostate gland ( prostatitis )
  • Testicles— epididymitis , a painful condition of the testicles that may lead to infertility
  • Rectum—inflammation of the rectum (anal intercourse)
  • Urethra—inside may become scarred; can make urinating difficult
In Women:

If you are diagnosed with chlamydia, follow your doctor's instructions .

Prevention

The safest action is to abstain from sex. If you are sexually active, you can prevent chlamydia by taking the following preventive measures:

  • Always use a latex condom during sexual activity. Other contraceptive tools may offer some protection. The condom is the most reliable of them all.
  • Have a monogamous relationship (only one sexual partner). Make sure your partner is monogamous as well.
  • Have routine check-ups often for STDs. This is especially important if you are under the age of 25.

If you already have chlamydia, you can prevent its transmission by:

  • Making sure that all sexual partners are tested and treated
  • Refraining from sexual activity until your infection is gone

Last reviewed: September 2011 by Lawrence Frisch, MD, MPH.

RESOURCES:
CANADIAN RESOURCES:
References:
  • Blas MM, Canchihuaman FA, Alva IE, Hawes SE. Pregnancy outcomes in women infected with Chlamydia trachomatis: a population-based cohort study in Washington State. Sex Transm Infect . 2007;83(4):314-318.
  • Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2010. MMWR 2010;59(No. RR-12):1-110.
  • Drugs for sexually transmitted infections. The Medical Letter . 2004;2:67.
  • DynaMed Editorial Team. Chlamydia genital infection. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated July 16, 2010. Accessed November 16, 2010.
  • Gottlieb SL, Martin DH, Xu F, Byrne GI, Brunham RC. Summary: The natural history and immunobiology of Chlamydia trachomatis genital infection and implications for Chlamydia control. J Infect Dis . 2010;201:Suppl 2:S190-204.
  • Kent CK, Chaw JK, Wong W, et al. Prevalence of rectal, urethral, and pharyngeal chlamydia and gonorrhea detected in 2 clinical settings among men who have sex with men: San Francisco, California, 2003. Clin Infect Dis . 2005;41:67-74.
  • Mayo Clinic. Chlamydia. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/chlamydia/DS00173 . Updated April 29, 2009. Accessed November 16, 2010.
  • National Institute of Allergy and Infectious Diseases. Chlamydia. National Institute of Allergy and Infectious Diseases website. Available at: http://www3.niaid.nih.gov/topics/chlamydia/default.htm . Updated April 2009. Accessed July 13, 2009.
  • National Women's Health Information Center. Chlamydia: frequently asked questions. The National Women's Health Information Center website. Available at: http://www.womenshealth.gov/ . Updated March 2009. Accessed July 13, 2009.