From the Guidelines
Nucleic acid amplification tests (NAATs) are the recommended screening method for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infections, with high sensitivity and specificity for specimens from various anatomical sites. The use of NAATs for screening CT and GC infections is supported by the U.S. Preventive Services Task Force (USPSTF) recommendation statement 1.
Key Points for Screening
- NAATs have high sensitivity and specificity for detecting CT and GC infections, with sensitivity ranging from 86% to 100% for CT and 90% to 100% for GC 1.
- The USPSTF recommends screening for CT and GC infections in asymptomatic patients, particularly those at increased risk, such as young women and men who have sex with men 1.
- Screening intervals should be based on individual risk factors, with more frequent screening recommended for those at higher risk 1.
- Treatment for CT and GC infections should be initiated promptly according to current guidelines, with antibiotic therapy being the recommended treatment 1.
Specimen Collection and Handling
- Specimens can be collected from various anatomical sites, including urine, endocervical, vaginal, and urethral specimens 1.
- Self-collected vaginal specimens and urine specimens are acceptable alternatives to clinician-collected specimens 1.
- Specimens should be handled and stored according to the manufacturer's instructions to ensure accurate test results 1.
From the Research
CT + GC Liquid Base for STIs Screening
- The use of liquid base for STIs screening, particularly for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC), has been evaluated in several studies 2, 3, 4, 5, 6.
- A study published in 2003 compared the detection of CT and GC using commercially available nucleic acid amplification tests and a liquid Pap smear medium, and found that the agreement between ligase chain reaction (LCR) performed on PreservCyt and LCR from a cervical swab was high 3.
- Another study published in 2023 found that vaginal swabs had higher sensitivity than urine specimens for detecting CT, GC, and Trichomonas vaginalis in women 4.
- A study published in 2020 found that cost, specimen type, and location of testing were important factors in determining testing preferences for STIs among female undergraduate students 5.
- The use of nucleic acid amplification tests (NAATs) for detecting CT and GC in rectal and pharyngeal specimens has also been evaluated, and several assays have been cleared by the Food and Drug Administration for this purpose 6.
Specimen Types
- Vaginal swabs are considered the optimal sample type for women being tested for CT, GC, and Trichomonas vaginalis 4.
- Urine specimens can also be used for STI testing, but may have lower sensitivity than vaginal swabs 4.
- Rectal and pharyngeal specimens can be used for STI testing, particularly for detecting CT and GC infections in these anatomic sites 6.