This website is part of the ECDC (European Centre for Disease Prevention and Control) network


Genital chlamydia is a sexually transmitted infection caused by the Chlamydia trachomatis bacterium. Sexually active young people are most at risk of chlamydia, and women below 24 years of age have the highest number of infections in Europe.

The EU and EEA/EFTA countries are expected to report genital chlamydia infections to ECDC. Chlamydia disease surveillance shows that the number of Chlamydia infections is increasing in Europe:  there are now more than 250 000 new cases reported each year. Many Chlamydia infections do not produce symptoms, and the growing number of reported cases is likely to be the result of increased awareness about the disease and intensified testing.

Chlamydia trachomatis infections can cause long-term complications in women even when they do not produce symptoms of acute disease. The most common complications are pelvic inflammatory disease (PID) and salpingitis, conditions that can lead to infertility and extra-uterine pregnancies. This risk of long-term reproductive health problems associated with C. trachomatis infections has lead some European countries to routinely offer testing for chlamydia to sexually active young people in an attempt to reduce the spread of the disease.

Lymphogranuloma venereum (LGV) is a special form of genital chlamydia that is caused by a sub-group of the Chlamydia trachomatis bacterium. LGV is very rare in Europe. Most reported cases result from infections acquired through unprotected sex in parts of the world where the disease is more common. 

Since 2003 an atypical form of LGV infection has been spreading in Europe among men who have sex with men. The disease presentation is different from traditional LGV in that the patients have symptoms of inflammation in the rectum (proctitis) and colon (haemorrhagic colitis), and often do not have urethritis or the swollen lymph nodes in the groins that are otherwise typical of LGV.

Control of genital chlamydia focuses on reducing sexual risk behaviour, condom use, early diagnosis, and effective management of sexual partners in order to break the chain of transmission.



Click a letter to find the health topic




© European Centre for Disease Prevention and Control (ECDC) 2005 - 2017