Chlamydia infection is a sexually transmitted disease caused by the bacterium Chlamydia trachomatis. The infection can also be transmitted from a mother to her baby during birth. Chlamydia infection often does not cause symptoms.
If symptoms do occur, they may include painful urination and abnormal discharge from the vagina, rectum, or penis. In women, there may also be abdominal pain and bleeding between periods or during sex.
Men may also have pain and swelling in the testes. Untreated, chlamydia infection may lead to pelvic inflammatory disease in women or epididymo-orchitis in men.
In developing countries, chlamydia infection is a cause of trachoma . Treatment with antibiotics usually clears up the infection. Sexual partners should be tested for the infection and, if necessary, offered treatment.