Chlamydia Test

Why this test may be ordered

• To check for a chlamydia infection when you don't have symptoms
• To diagnose or rule out chlamydia when you do have symptoms
• If your sex partner has been diagnosed with chlamydia
• As routine screening for sexually active women under 25, pregnant women, men who have sex with men, and people with HIV
• To test for reinfection three months after treatment

Preparation and collection

Preparations depend on the type of sample you will provide. You may need to avoid antibiotic medicines and vaginal douches or creams for 24 hours before the test. For a first-catch urine sample, avoid urinating for two hours before the test. Do not stop any medicines without talking with your provider first.

For a first-catch urine sample, you collect the very first part of your urine stream into a sterile cup. For a swab sample, your provider uses a special swab to collect cells from your genital area (or other sites); you may feel brief discomfort. Some tests allow you to swab yourself. At-home collection kits are also available.

According to MedlinePlus, there are no known risks to having a chlamydia test.

Understanding results

Your test results will show whether the bacteria that cause chlamydia were found in your sample. Your healthcare provider will interpret the results in the context of your symptoms, sexual history, and other factors.

• Negative: No chlamydia infection was detected in the sample collected. This means you did not have a chlamydia infection at the time of the test. Limitation: A negative result does not completely rule out infection if you were exposed very recently (before the bacteria could be detected) or if the sample was not collected correctly. False negatives can occur. Next step: If you have symptoms or high risk of exposure, your provider may recommend repeat testing or testing for other STIs.
• Positive: You have been infected with chlamydia. Limitation: False positives are rare but possible. The test detects genetic material or antigens from the bacteria; it does not indicate how long you have been infected or whether you will develop symptoms or complications. Next step: You will need to take antibiotics as prescribed, finish all the medicine, tell your sexual partners so they can be tested and treated, and get retested for chlamydia three months after finishing treatment because repeat infections are common.

• A negative result does not completely rule out infection if exposure occurred shortly before testing or if the sample was not collected properly.
• A positive result confirms infection but does not provide information about the duration of infection or potential complications.
• The test cannot distinguish between a new infection and a repeat infection.
• At-home test kits require careful following of instructions; incorrect collection or handling may affect accuracy.
• The test only checks for chlamydia; if you have symptoms of other STIs, separate testing may be needed.

What to do next

If you test positive, follow your provider's treatment plan exactly, notify all recent sexual partners, and get retested in three months. If you test negative but have symptoms or ongoing risk, discuss with your provider whether repeat or additional STI testing is appropriate. Pregnant women with positive results should receive treatment to prevent passing the infection to the baby.

• Should I be tested for chlamydia even if I have no symptoms?
• How long after exposure should I wait to get tested for chlamydia?
• What should I tell my sexual partner(s) if I test positive?
• When should I get retested after finishing treatment?
• Can chlamydia be cured, and will the test show if I am cured after treatment?

Evidence source

U.S. National Library of Medicine: Chlamydia Test