We present 2 studies conducted on Chlamydia trachomatis(CT) and Trichomonas vaginalis(TV) testing in NHSG, leading to streamlining of NAATs of Neisseria gonorrhoeae, CT and TV in triplex.


Formerly, positive CT-NAATs needed confirmation by repeat testing on the same sample using same platform. According to SMI guidelines, when confirmatory testing results are consistently concordant following audit, confirmation may be unnecessary. CT testing over 3 years (2015-2017) was analysed to review outcomes of confirmatory testing.

A pilot study was conducted on TV-NAAT testing in comparison with TV-microscopy. In addition, TV testing data over 30months (29/07/2016-31/01/2019) was analysed.


A total of 88533 samples were tested for CT-NAAT over 3 years: 7059 were positive, 81321 negative. A total of 153 were equivocal (initially positive, negative on repeat) which were reanalysed with results on receival of repeat samples. Over the years, percentage of equivocal tests out of the total positives remained at 0.2%; rates for positive-repeats and tests-not-repeated fluctuated; negative-repeats increased from 18 to 38.

TV-NAAT was more sensitive/ specific compared to TV-microscopy (relative specificity was 99.6%, relative sensitivity was 92.8%), and was adopted for routine testing. A total of 44407 samples were tested for TV NAATs over 30 months. Of this, 433 were positive and 43796 negative. Further cross-sectional analyses were done.


We concluded that positive CT-NAATs do not require repeat testing for confirmation. TV-NAAT testing proved more sensitive/specific than TV-microscopy and was useful to adopt as routine testing and help streamlining testing on one molecular platform.

  • This is an open-access article distributed under the terms of the Creative Commons Attribution License.

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