Chlamydia is at type of bacteria. There are several different species of chlamydia. A number of strains within each species are responsible for a variety of diseases in birds, humans, and other mammals. Their most common appearance is as a sexually transmitted disease (STD) referred to as chlamydia or nongonococcal urethritis (NGU).
Chlamydia is one of the most common STDs in the US, especially among sexually active teens and young adults. Prevalence is highest in people 25 years old and younger.
Chlamydia can lead to Reiter’s syndrome, which is a triad of arthritis, conjunctivitis, and urethritis. It can also cause neonatal infections such as pneumonia or conjunctivitis when passed from an infected mother. It can also cause infections in the throat or rectum through oral or anal intercourse.
Other types of chlamydia can cause:
Genital chlamydial infections are caused when Chlamydia trachomatis is transmitted during oral, vaginal, or anal sex from an infected partner.
Chlamydia. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/std/chlamydia/default.htm. Updated April 30, 2013. Accessed May 16, 2013.
Chlamydia genital infection. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. Updated March 13, 2013. Accessed May 16, 2013.
Chlamydia fact sheet. US Department of Health and Human Services Women's Health website. Available at: http://www.womenshealth.gov/. Updated July 8, 2011. Accessed May 16, 2013.
Workowski KA, Berman S, Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2010. MMWR. 2010;59(No. RR-12):1-110.
Last reviewed May 2013 by Brian Randall, MD
Last Updated: 5/16/2013