Chlamydia tests use a sample of body fluid or urine 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 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 problem 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. This test can also be done on a urine sample.
If you have chlamydia, all of your sex partners from the last 60 days should be tested and treated. And you may need to have tests for other sexually transmitted infections, including HIV.
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Why It Is Done
A test for chlamydia is done to:
- See if your symptoms of a sexually transmitted infection (STI) are caused by a chlamydia infection.
- Check people who are at high risk for being infected with chlamydia. A chlamydia infection doesn't always cause symptoms.
- Retest people several months after they have been treated for chlamydia.
- Check for infection in your newborn if you had a chlamydia infection at the time of delivery.
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 at least 1 hour before the sample is collected.
How It Is Done
Do not wipe the genital area clean before urinating. Collect the first part of your urine stream, just as you start to urinate.
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 exam.
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.
No chlamydia antigens or DNA are found. More tests for other sexually transmitted infections (STIs) may be needed to find the cause of symptoms.
Chlamydia antigens or DNA are found.
Current as of: August 2, 2022
Author: Healthwise Staff
Medical Review:Sarah Marshall MD - Family Medicine & E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Devika Singh MD, MPH - Infectious Disease