Test Overview

Chlamydia tests generally use a urine sample, but they can also use a swab to see whether chlamydia bacteria (Chlamydia trachomatis) are present and causing an infection.

Nucleic acid amplification tests (NAAT) are used to find chlamydia infection. These tests use urine or a sample of body fluid from areas such as the cervix, vagina, eyes, rectum, or throat to find the genetic material (DNA) of chlamydia bacteria. These tests are very good at identifying chlamydia. A test that is positive almost always means the infection is there and is unlikely to be a false-positive test result. A polymerase chain reaction (PCR) test is an example of a nucleic acid amplification test.

If you have chlamydia, all of your sex partners from the last 60 days should be tested and treated^{footnote 1}. You may need to have tests for other sexually transmitted infections, including HIV and syphilis.

Why It Is Done

A test for chlamydia is done to:

• See whether symptoms of a sexually transmitted infection (STI) are caused by a chlamydia infection.
• Check people who are at higher risk for being infected with chlamydia. Chlamydia may not cause symptoms or it is possible the symptoms may go away without treatment. Unless you have a test, you may not know that you have it.
• Retest people 6 months after they have been treated for chlamydia, or earlier if at higher risk.
• Check for infection in a newborn whose mother had a chlamydia infection at the time of delivery.

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How To Prepare

A chlamydia test is done on either a urine sample or fluid (direct sample) collected from the area of the body that is most likely to be infected. If your test is being done on a urine sample, do not urinate for 2 hours before the sample is collected.

How It Is Done

Urine sample

Do not wipe the genital area clean before urinating. Collect the first part of your urine stream, just as you start to urinate. Give the amount of urine that is indicated in the instructions. Giving too much or too little may affect the results of your test.

Direct sample

In a direct sample, a sample of body fluid is taken from the affected area. These areas may include the cervix, vagina, rectum, throat, or eyes. Your doctor may use a swab to collect the sample. Or you may be given instructions on how to collect your own sample.

How long the test takes

The test will take a few minutes.

How It Feels

There is no discomfort in collecting a urine sample.

Collecting a sample of fluid from the vagina, rectum, throat, or eyes may cause mild discomfort or pain.

Collecting a sample from the cervix may cause mild discomfort. It may feel like having a Pap test or pelvic examination.

Risks

There is no chance for problems in collecting a urine sample.

There is very little chance of problems when collecting a sample of fluid from the cervix, vagina, rectum, eyes, or throat.

Results