Chlamydia is a bacterial infection. It causes inflammation of the mucous membranes, usually in the urethra, vagina, rectum and anal area. Chlamydia bacteria can also affect the mouth and throat. Chlamydia infections are among the most common sexually transmitted infections.

Chlamydia infections are usually more severe in people with HIV. A Chlamydia infection raises the risk of transmitting HIV, as the inflamed mucous membranes and their secretions contain a very high level of virus. HIV-negative people with a Chlamydia infection are at a higher risk of becoming infected with HIV because the virus can enter the body more easily through inflamed skin or mucous membranes.


A Chlamydia infection often has no symptoms whatsoever. If symptoms do appear, then one to three weeks after infection you may experience discharge from the urethra, itching and burning when urinating. An untreated Chlamydia infection can spread to other parts of the body.

In men, the vas deferens (spermatic ducts), prostate and epididymis can become inflamed. In women, the infection can spread to the abdominal cavity and the fallopian tubes. In some cases, an untreated Chlamydia infection can lead to infertility.


In a person with Chlamydia, the bacteria are present in the mucous membranes of the urethra, vagina and rectum, as well as in vaginal fluid and semen. They are also present in urine and pre-cum, at lower levels. An infection is possible through any sexual activity that involves direct contact with infectious mucous membranes or bodily fluid.

The most common method of transmission is unprotected vaginal or anal sex. But Chlamydia is sometimes also transmitted on the hands or on sex toys.


Condoms cannot entirely prevent a Chlamydia infection, but they reduce the risk considerably.

For an infection to be diagnosed promptly and not passed on, people with frequently changing sexual partners should be tested regularly for Chlamydia.

Women under the age of 26 can be tested once a year, paid for by their health insurance fund. Pregnant women should also be tested for Chlamydia, as the bacteria can lead to premature birth and to an infection for the newborn baby.


Chlamydia can be tested for with a swab (by women) or a urine sample (by men).


Chlamydia can be effectively treated with antibiotics. The earlier you begin treatment, the easier and quicker the treatment usually is.

Because of the high risk of infecting others, you should avoid having sex until the treatment is finished. Your sexual partners should also be tested and treated if necessary, to prevent a "ping-pong" effect, where the infection is passed back and forth between partners.