A diagnostic evaluation of a molecular assay used for testing and treating anorectal chlamydia and gonorrhoea infections at the point-of-care in Papua New Guinea.

OBJECTIVES: Papua New Guinea has among the highest prevalences of sexually transmissible infections (STIs) globally with no services able to accurately test for anorectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections. Here we prospectively evaluated the diagnostic performance of a molecular CT/NG assay used at the point-of-care (POC) with the aim of enhancing anorectal STI screening and same-day treatment. METHODS: Men who have sex with men, transgender women and female sex workers taking part in Papua New Guinea's first large-scale biobehavioural study were enrolled and asked to provide a self-collected anorectal swab for POC GeneXpert CT/NG testing. Same-day treatment was offered if positive. A convenience sample of 396 unique and randomly selected samples were transported to Australia for comparison using the Cobas 4800 CT/NG test (Roche Molecular Diagnostics, Pleasanton, CA, USA). RESULTS: A total of 326 samples provided valid results by Cobas whereas 70 samples provided invalid results suggesting inhibition. The positive, negative and overall percentage agreements of GeneXpert CT/NG for the detection of C. trachomatis were 96.7% (95% CI 92.3%-98.9%), 95.5% (95% CI 91.3%-98.0%) and 96.0% (95% CI 93.3%-97.8%), and for N. gonorrhoeae were 93.0% (95% CI 86.1%-97.1%), 100.0% (95% CI 98.3%-100.0%) and 97.8% (95% CI 95.6%-99.1%), respectively. CONCLUSIONS: The overall rate of agreement between the GeneXpert and Cobas CT/NG assays was high with 96.0% for C. trachomatis and 97.8% for N. gonorrhoeae. Results from this study data suggest that the GeneXpert CT/NG assay is suitable for testing self-collected anorectal specimens at the POC and that same-day treatment was feasible.

Field Evaluation of Xpert HPV Point-of-Care Test for Detection of Human Papillomavirus Infection by Use of Self-Collected Vaginal and Clinician-Collected Cervical Specimens.

The World Health Organization has recommended that testing for high-risk human papillomavirus (HPV) (hrHPV) infection be incorporated into cervical screening programs in all settings worldwide. In many high-burden, low-income countries, it will not be feasible to achieve high cervical screening coverage using hrHPV assays that require clinician-collected samples. We conducted the first evaluation of self-collected vaginal specimens compared with clinician-collected cervical specimens for the detection of hrHPV infection using the Xpert HPV test. Women aged 30 to 54 years attending two well-woman clinics in Papua New Guinea were invited to participate and provided self-collected vaginal and clinician-collected cervical cytobrush specimens. Both specimen types were tested at the point of care by using the Xpert HPV test. Women were given their cervical test result the same day. Those with a positive hrHPV test and positive examination upon visual inspection of the cervix with acetic acid were offered same-day cervical cryotherapy. A total of 1,005 women were enrolled, with 124 (12.3%; 95% confidence interval [CI], 10.3%, 14.4%) being positive for any hrHPV infection. There was a 99.4% overall percent agreement (OPA) between vaginal and cervical tests for HPV-16 (95% CI, 98.9%, 99.9%), a 98.5% OPA for HPV-18/45 (95% CI, 97.7%, 99.3%), a 94.4% OPA for other hrHPV infections (95% CI, 92.9%, 95.9%), and a 93.4% OPA for all hrHPV types combined (95% CI, 91.8%, 95.0%). Self-collected vaginal specimens had excellent agreement with clinician-collected cervical specimens for the detection of hrHPV infection using the Xpert HPV test. This approach provides for the first time an opportunity to incorporate point-of-care hrHPV testing into clinical cervical screening algorithms in high-burden, low-income settings.