Increased testing for Neisseria gonorrhoeae with duplex nucleic acid amplification tests in Australia: implications for surveillance

Sex Health. 2015 Mar;12(1):48-50. doi: 10.1071/SH14179.


Background Gonorrhoea notifications have been increasing in Australia's cities, in both men and women. We investigated if this could be, at least in part, a result of a testing artefact.

Methods: We surveyed 28 laboratories that were known to test for both Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) to determine their testing and reporting practices, and when these practices were instituted.

Results: By 2012, 23 (82%) of the laboratories were routinely performing duplex nucleic acid amplification tests for both CT and NG even if a test for only one organism was requested, up from 9 (32%) laboratories before 2007. Although written reports of negative NG tests were not provided if the test was not requested, positive NG tests were always communicated to the attending clinician.

Conclusions: The move towards routine duplex testing for CT and NG has probably resulted in more Australians being tested for NG than ever before. While this change has advantages for case-finding and improved public health outcomes, it also brings an increasing potential for false-positive NG tests. Recent trends in NG notifications should be interpreted with caution.