A reliable and easy to transport quality control method for chlamydia and gonorrhoea molecular point of care testing

S. G. Badman, L. M. Causer, R. Guy, H. Wand, B. Donovan, S. N. Tabrizi, D. Speers, M. D. Shephard, A. Vallely, D. Whiley, John Kaldor, David Wilson, David Regan, James Ward, Christopher K. Fairley, Belinda Hengel, Annie Tangey, David Anderson, Lisa Natoli, David Atkinson & 1 others the TTANGO investigators

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Quality control (QC) is an essential component of point-of-care testing programs. In the context of a randomised-controlled trial (TTANGO) using GeneXpert (Xpert) Chlamydia trachomatis and Neisseria gonorrhoeae (CT/NG) point-of-care testing in remote areas of Australia, we aimed to develop and utilise a stable positive control material. Bacterial cultures of CT and NG were resuspended together to provide cycle threshold (Ct) values of approximately 25 cycles for both CT and NG when tested on the Xpert CT/NG assay. These positive control suspensions were dried in aliquots, heat inactivated, and then provided to 12 participating health services as research-only QC samples in kit form. At each service, a QC sample was resuspended and tested each month on the Xpert. QC results, including Xpert Ct values, were analysed from each site over 30 months and we calculated costs per QC sample. Overall, at 12 health services there were 89 QC samples tested (average of 8 tests per site per year). Mean Ct values for the 89 controls samples were 25.25 cycles (SD = 1.15) for CT, 24.04 cycles (SD = 1.400) for one NG target and 23.35 cycles (SD = 1.55) for the other NG target. No significant differences in Ct value for CT or NG controls were observed over a trial period of 30 months. Positive QC samples for research use in a trial of a molecular point-of-care assay were inexpensive to produce and stable when stored at 2–8°C. For routine use, additional requirements such as meeting National Association of Testing Authority (NATA) regulations and Therapeutic Goods Administration (TGA) approval will need to be achieved.

LanguageEnglish
Pages317-321
Number of pages5
JournalPathology
Volume50
Issue number3
DOIs
Publication statusPublished - 1 Apr 2018

Keywords

  • DNA
  • GeneXpert
  • assurance
  • chlamydia
  • control
  • gonorrhoea
  • point-of-care
  • quality

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Cite this

Badman, S. G., Causer, L. M., Guy, R., Wand, H., Donovan, B., Tabrizi, S. N., ... the TTANGO investigators (2018). A reliable and easy to transport quality control method for chlamydia and gonorrhoea molecular point of care testing. Pathology, 50(3), 317-321. https://doi.org/10.1016/j.pathol.2017.09.012