Repeat testing of the same positive sample using the same NAAT methodology is usually not needed and does not improve the positive predictive value when screening with currently available NAATs.5 Positive results are considered presumptive evidence of infection.
If a false-positive result is expected to have adverse medical, social, or psychological consequences, confirmatory testing should be considered.10 Confirmatory testing using an alternative nucleic acid target region, should also be considered in low-prevalence settings, where the positive predictive value (likelihood that a positive result is a true positive) of assays is reduced (note that testing of asymptomatic people is not recommended in extremely low-prevalence settings5). Treatment probably should not be withheld while awaiting the results of confirmatory testing.
The following tests target alternative nucleic acid and can thus be used to confirm positive test results-
- Test Code 15031-Chlamydia trachomatis RNA, TMA, Alternate Target
- Test Code 91046-Chlamydia trachomatis RNA, TMA, Alternate Target, Rectal
- Test Code 15033-Neisseria gonorrhoeae RNA, TMA, Alternate Target
- Test Code 90990-Neisseria gonorrhoeae RNA, TMA, Alternate Target, Rectal