Different Types of Chlamydia Tests

A sample of urine or other body fluid is used to be able to perform Chlamydia tests, and to check if Chlamydia trachomatis is present and is the cause of the infection. In the United States, Chlamydia is one of the most prevalent sexually transmitted disease or most commonly known as STD.

There are several kinds of tests that can be done to assess whether a person is infected with Chlamydia or not. These tests can be taken at nearby STD clinics which can help you in diagnosing the disease. Majority of the tests require a sample--usually from body fluids--to be extracted from an affected area.

•Nucleic acid amplification tests (NAAT). In these test, the DNA or the genetic material of the Chlamydia bacteria is detected. These types of tests are the most sensitive at present. Therefore, the results are very accurate and there is a very low chance that a false-positive result would occur. A molecular biology technique called the polymerase chain reaction or PCR is one example of a nucleic acid amplification procedure. This test can be performed using samples of urine.

•Nucleic acid hybridization tests (DNA probe test). Chlamydia DNA can also be detected using a probe test. This test is also very accurate, but it is less sensitive than DNA amplification tests.

•Enzyme-linked immunosorbent assay (ELISA, EIA). This technique detects Chlamydia antigens which trigger a person's immune system to combat Chlamydia infection.

•Direct fluorescent antibody test (DFA). This is a fast technique which also detects chlamydia antigens.

•Chlamydia culture. In this test, a special cup is used to allow Chlamydia bacteria to multiply and grow. This is a more expensive test and you have to wait longer for the results, usually around five to seven days. The culture must be prepared in the laboratory. The Chlamydia culture test is usually done when a child is suspected of having experienced sexual abuse, or when treatment has not worked.

Why It Is Done

The different tests for Chlamydia are done because of the following reasons:

•To check if symptoms and warning signs of a sexually transmitted disease (STD) are brought about by a Chlamydia infection.

•If the mother is infected with Chlamydia during the time of delivery, the newborn must be check for Chlamydia as well.

•To determine people who are at high risk for being infected with Chlamydia and those who are already infected. A Chlamydia infection does not always manifest symptoms. The U.S. Preventive Services Task Force (USPSTF) suggests testing for Chlamydia for:

- All sexually active women aged 24 or younger.
- Women who are older than age 24 practicing high-risk sexual behaviors.
- All pregnant women in the first trimester and again in the third trimester if high-risk sexual behaviors are reported. A pregnant woman who has a Chlamydia infection must be treated immediately so that the infection would not be transmitted to her newborn.
- All women who have pelvic inflammatory disease (PID).
- All women with symptoms of cervicitis or cervical infection found on a pelvic exam.

How to Prepare

A Chlamydia test is performed on either bodily fluid (direct sample) collected from the area of the body that is suspected to be infected or on a urine sample. If your Chlamydia test is being performed on a:

•Direct sample (normally from the cervix): A woman should not use vaginal creams or douche or use medicines for 24 hours before undergoing a Chlamydia test.
•Urine sample: Refrain from urinating for two hours before a urine sample is collected.