Chlamydial infections include sexually transmitted diseases of the urethra, cervix, and rectum that are caused by the bacteria Chlamydia trachomatis. These bacteria can also infect the membranes that cover the whites of the eyes (conjunctiva) and the throat. Other bacteria, such as Ureaplasma and Mycoplasma, can also cause infections of the urethra.
Symptoms include a discharge from the penis or vagina and painful or more frequent urination.
If unnoticed or untreated in women, these infections can result in infertility, miscarriage, and an increased risk of a mislocated pregnancy.
DNA tests of a sample of the discharge or of urine can detect chlamydial infection.
Antibiotics can cure the infection, and sex partners should be treated at the same time.
Several bacteria can cause diseases that resemble gonorrhea. These bacteria include Chlamydia trachomatis (chlamydiae), Ureaplasma, and Mycoplasma. Laboratories can identify chlamydiae but have difficulty identifying the other bacteria.
Chlamydial infection is the most commonly reported sexually transmitted disease (STD). In the United States, over 1.4 million cases were reported in 2014. Because the infection frequently causes no symptoms, twice as many people may be infected.
In men, chlamydiae cause about half of the urethral infections (urethritis) not caused by gonorrhea. Most of the remaining urethral infections in men are probably caused by Ureaplasma urealyticum or Mycoplasma genitalium. In women, chlamydiae account for virtually all of the cervical infections (cervicitis) that produce pus and that are not caused by gonorrhea. Sometimes both sexes have gonorrhea and chlamydial infection at the same time.
Chlamydial infection can also be spread during oral sex, causing infection of the throat.