From the Guidelines
A nucleic acid amplification test (NAAT) is the recommended confirmatory test for a positive Chlamydia screen. This test can be performed using a urine sample or a swab from the site of infection, and it provides a definitive diagnosis for medical records and helps in tracking the epidemiology of the infection 1. The high sensitivity and specificity of NAAT make it an ideal choice for confirming a positive Chlamydia screen.
Some key points to consider when confirming a positive Chlamydia screen include:
- The importance of prompt treatment to prevent serious complications, even if the confirmatory test results are pending 1
- The need for partner notification and treatment to prevent reinfection and transmission to others 1
- The recommendation for a follow-up appointment 3 months after treatment to ensure cure and rule out reinfection
It is essential to note that while treatment should not be delayed, a confirmatory test is still necessary to verify the diagnosis and provide a definitive result. NAAT is the preferred method for confirming a positive Chlamydia screen due to its high sensitivity and specificity. By following these guidelines, healthcare providers can ensure that patients receive prompt and effective treatment, while also preventing the spread of the infection to others 1.
From the Research
Confirming Positive Chlamydia Screens
To confirm a positive Chlamydia (Chlamydia trachomatis) screen, several approaches can be taken, including:
- Repeat testing of the original specimen using the same nucleic acid amplification test (NAAT) 2
- Retesting the original specimen with a different NAAT 2, 3
- Performing a different test on a duplicate specimen 2
- Using an alternative amplification target for confirmatory testing 3
Effectiveness of Confirmatory Testing Approaches
Studies have shown that:
- Repeat testing can confirm 84 to 98% of positive results 2
- Retesting with a different NAAT can confirm 89 to 99% of positive results 2
- Using an alternative amplification target for confirmatory testing can confirm 81% of low-positive C. trachomatis screens 3
- The use of multiple NAATs can help define the infected-patient "gold standard" in clinical trials of new diagnostic tests for Chlamydia trachomatis infections 4
Considerations for Confirmatory Testing
It is important to note that:
- Not all NAATs are created equal, and some may not be suitable for confirmatory testing 5
- The choice of confirmatory testing approach may depend on the specific NAAT used for initial screening 2, 3
- Molecular confirmatory testing may not significantly enhance the reliability of C. trachomatis-specific nucleic acid amplification testing in all settings 3