2025 Review of Public Health Laboratory Network Australia Neisseria gonorrhoeae National Nucleic Acid Amplification Testing Guidelines

Abstract

Since the introduction of Neisseria gonorrhoeae nucleic acid amplification tests (NG-NAATs) into routine clinical use, false-positive results caused by cross-reaction with non-gonococcal Neisseria species have been an issue, particularly in specimens from the pharynx. Therefore, since 2005 in Australia, a confirmatory assay has been recommended, with a positive result issued only when both assays are concordant.

At the request of the Public Health Laboratory Network (PHLN) Australia, the National Neisseria Network (NNN) met to review the 2015 PHLN NG-NAATs Guidelines in October 2024, in the context that some later generation N. gonorrhoeae NAATs have claims for testing pharyngeal samples without the need for supplemental testing for confirmation. Adequacy of performance in this context was considered by the NNN as a positive predictive value of 95% in line with World Health Organization guidance.

Based on the 2024 review, it is recommended that:

1. Supplementary testing continue to be performed for all non-urogenital (pharyngeal and rectal) samples.
2. Supplementary testing be at the discretion of individual laboratories, based on local validation data demonstrating adequate performance based on WHO recommendations, for urogenital samples. Additional testing should continue to be considered when testing low-risk populations.