Direct urine polymerase chain reaction for chlamydia and gonorrhoea: a simple means of bringing high-throughput rapid testing to remote settings?

Frashta Rahimi, Namraj Goire, Rebecca Guy, John M. Kaldor, James Ward, Michael D. Nissen, Theo P. Sloots, David M. Whiley

Background Rapid point-of-care tests (POCTs) for chlamydia (Chlamydia trachomatis) and gonorrhoea (Neisseria gonorrhoeae) have the potential to confer health benefits in certain populations even at moderate sensitivities; however, suitable POCTs for these organisms are currently lacking. Methods: In this study, we investigated the use of direct urine polymerase chain reaction (PCR), with the view of implementing a simplified PCR strategy for high-throughput chlamydia and gonorrhoea screening in remote settings. Briefly, a simple dilution of the urine was performed before adding it directly to a real-time PCR reaction. The method was evaluated using 134 stored urine specimens that had been submitted for chlamydia and gonorrhoea testing and had been tested using a commercial C. trachomatis and N. gonorrhoeae PCR method. These included samples that were PCR-positive for chlamydia (n=87), gonorrhoea (n=16) or both (n=2). Direct urine testing was conducted using previously described in-house real-time PCR methods for C. trachomatis and N. gonorrhoeae as well as for recognised N.gonorrhoeae antimicrobial resistance mechanisms. Results: The overall sensitivities and specificities of the direct urine PCR were 78% and 100% for chlamydia, and 83% and 100% for gonorrhoea. N.gonorrhoeae penicillin and quinolone resistance mechanisms were characterised in 14 of the 18 N. gonorrhoeae-positive samples. Conclusions: The results of this study show that the simplified PCR strategy may be a feasible approach for rapid screening and improving chlamydia and gonorrhoea treatment in remote settings.