Investigations

1st investigations to order

Test
Result
Test

Noninvasive sampling (urine or vaginal) is as effective as invasive sampling (vaginal, endocervical, or penile urethral swab) and is more acceptable to patients.[14]

Rectal and oropharyngeal Chlamydia trachomatis infection can be diagnosed by testing at the anatomic site of exposure. In the US, NAATs are not FDA-cleared for use with rectal or oropharyngeal swab specimens. However, some laboratories have met Clinical Laboratory Improvement Amendments (CLIA) of the Centers for Disease Control and Prevention requirements for NAATs testing validation and can perform these tests.[11] There is also good evidence that performance of NAATs on patient self-collected rectal swabs is comparable to clinician-collected rectal swabs, and patients find this self-collection method for chlamydial screening highly acceptable.[12][13]

Sensitivity is high (>90%), as is specificity (94% to 99.5%). NAAT can detect as little as a single strand of DNA to produce a positive result. Chlamydia organisms do not need to be viable in order to obtain a positive result.[11]

If NAAT is negative, but clinical suspicion is high, treat the patient empirically.

There is increasing use of near patient rapid NAATs that can provide results within 90 minutes.[15]

Result

positive

Investigations to consider

Test
Result
Test

Requires an invasive sample (vaginal, endocervical, or penile urethral swab) and is highly specific but less sensitive than NAAT.[16]

Result

positive

Test
Result
Test

Requires an invasive sample (vaginal, endocervical, or penile urethral swab) and has a sensitivity of about 50% of that of NAAT. The specificity is operator-dependent.[16]

Result

positive

Test
Result
Test

Requires an invasive sample (vaginal, endocervical, or penile urethral swab).

Result

positive

Test
Result
Test

Requires an invasive sample (vaginal, endocervical, or penile urethral swab). High specificity (close to 100%). Sensitivity varies depending on laboratories (70% to 90%).[11] Due to variability and expense, this test is usually only used in cases where legal issues are involved.

Result

positive

Emerging tests

Test
Result
Test

Allow diagnosis and treatment decisions to be made at initial presentation.

Currently available tests have low accuracy or are expensive to carry out, but there are many point-of-care tests being developed, such as rapid molecular testing for chlamydia, with some evidence that they can improve diagnosis and reduce unnecessary treatment.[17][18][19]

Result

positive

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