What is Chlamydia?


Chlamydia trachomatis is the most common bacterial cause of sexually transmitted genital infection.

There are more than 200,000 cases per year in the United States.


The incubation period for symptoms ranges from 5 to 14 days. Most people with Chlamydia do not have any symptoms.

Infants that are born with mothers who have Chlamydia may get conjunctivitis or pneumonia.

If someone has symptoms it may fall into different clinical syndromes depending on if they are a man or woman.

In women the most commonly affected site is the cervix, leading to cervicitis which may present as vaginal discharge and vaginal bleeding. If left untreated this can lead to pelvic inflammatory disease. Chlamydia may also lead to urethritis, with sometimes such as pain and burning with urination and increased frequency urinating. Less commonly patients with chlamydia may develop inflammation of the liver, known as perihepatitis or Fitz-Hugh-Curtis Syndrome.

In men Chlamydia is the most common cause of non-gonococcal urethritis, which presents as pain and burning with urination and urethral discharge. It may also cause epididymitis, which presents as testicular pain, tenderness and swelling. Prostatitis can also occur which may present as pain and burning with urination, pelvic pain, pain with sexual intercourse, and pain with ejaculation.

Both men and women with Chlamydia may present with conjunctivitis, pharyngitis, proctitis or rectal infection, Genital lymphogranuloma venereum or reactive arthritis.

If someone has recurrence of symptoms after treatment and improvement then they should have the test repeated.


The test of choice for diagnosing chlamydia is the nucleic acid amplification test. Other testing modalities include culture, antigen detection and genetic probes.

For genitourinary infection in women, urine, endocervical or vaginal swab can be done.

For genitourinary infections in male urethral or urine swabs can be done.

If suspecting conjunctivitis due to chlamydia a conjunctival swab can be done.

For pharyngitis due to chlamydia a pharyngeal swab can be done.


The goal of treatment of Chlamydia is to prevent complications and prevent transmission. Chlamydia is treated with antibiotics. All patients with a diagnosis of Chlamydia should also be tested for Gonorrhea, HIV and Syphilis.

Anyone diagnosed with Chlamydia should be retested 3 months after treatment. In some people it is recommended to test 4 weeks after treatment to confirm appropriate treatment.


Using condoms and spermicides helps to decrease the transmission of Chlamydia.