Quality control and external quality assessment for the independent clinic-based evaluation of point-of-care testing to detect Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis in eight countries.

BACKGROUND: Sexually transmitted infections caused by Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) remain significant global health problems. The World Health Organization (WHO) has recently conducted a multi-faceted, multi-country validation study (ProSPeRo), which included an evaluation of the Xpert CT/NG and Xpert TV assays on the GeneXpert system (Cepheid, Sunnyvale, Ca., USA) in clinic-based settings across eight countries. To support the study, a training and quality management system was implemented and evaluated. METHODS: A comprehensive training program for the study was developed. Quality control (QC) and external quality assessment (EQA) samples were provided by an accredited quality assurance provider. QC testing was conducted at 14 point-of-care testing (POCT) clinics, while EQA samples were tested by the POCT sites and a reference laboratory supporting each clinic. RESULTS: For QC testing, concordance with the expected results for CT and NG was > 99% and rates of unsuccessful tests were < 4%. For TV testing, concordance was similar (97%), but rates of unsuccessful tests were high (18%), particularly in the 'TV negative' sample. For EQA testing initially conducted in 2018, concordance was 100% for CT and NG, and 90% for TV for the reference laboratory group (which used non-GeneXpert systems). Concordance for the POCT group was also high (> 94%) for all analytes, but this cohort (which used GeneXpert systems) exhibited a high rate of unsuccessful TV tests. All but one of these unsuccessful tests was subcategorised as 'invalid'. CONCLUSIONS: The high level of concordance for QC and EQA testing confirm that the trained operators at the POC clinical sites were competent to conduct POC testing and that the training and quality systems implemented for the ProSPeRo study were effective. The quality materials used were satisfactory for CT and NG but exhibited poor performance for TV testing on the GeneXpert system. The WHO should continue to work with industry and EQA providers to provide improved materials that are reliable, stable and cost effective for quality management, as it seeks to rollout molecular-based STI POCT in non-laboratory-based settings. TRIAL REGISTRATION: Ethics approval to conduct the ProSPeRo study was granted by the WHO Ethics Review Committee.

Independent clinic-based evaluation of dual POCTs for screening for HIV and syphilis in men who have sex with men in Italy, Malta, Peru, and the United Kingdom.

INTRODUCTION: Globally, the incidence of HIV and syphilis can be reduced by the use of validated point of care tests (POCTs). As part of the WHO PRoSPeRo Network, we aimed to evaluate the performance, acceptability, and operational characteristics of two dual HIV/syphilis POCTs (Bioline HIV/Syphilis Duo (Abbott) and DPP® HIV-Syphilis assay (Chembio) for the screening of HIV and syphilis amongst men who have sex with men (MSM). METHOD AND ANALYSES: A cross sectional study of 2,577 MSM in Italy, Malta, Peru, and the United Kingdom (UK) presenting to seven clinic sites, were enrolled. Finger prick blood was collected to perform POCTs and results compared with standard laboratory investigations on venepuncture blood. Acceptability and operational characteristics were assessed using questionnaires. Diagnostic meta-analysis was used to combine data from the evaluation sites. RESULTS: Based on laboratory tests, 23.46% (n = 598/2549) of participants were confirmed HIV positive, and 35.88% of participants (n = 901/2511) were positive on treponemal reference testing. Of all participants showing evidence of antibodies to Treponema pallidum, 50.56% (n = 455/900) were Rapid Plasma Reagin (RPR) test reactive. Of HIV positive individuals, 60.62% (n = 354/584) had evidence of antibodies to T. pallidum, and of these 60.45% (n = 214/354) exhibited reactive RPR tests indicating probable (co)infection. For Bioline POCT, pooled sensitivities and specificities for HIV were 98.95% and 99.89% respectively, and for syphilis were 73.79% and 99.57%. For Chembio pooled sensitivities and specificities for HIV were 98.66% and 99.55%, and for syphilis were 78.60% and 99.48%. Both tests can detect greater than 90% of probable active syphilis cases, as defined by reactive RPR and treponemal test results. These dual POCTs were preferred by 74.77% (n = 1,926) of participants, due to their convenience, and the operational characteristics made them acceptable to health care providers (HCPs). CONCLUSIONS: Both the Bioline and the Chembio dual POCT for syphilis and HIV had acceptable performance, acceptability and operational characteristics amongst MSM in the PRoSPeRo network. These dual POCTs could serve as a strategic, more cost effective, patient and healthcare provider (HCP) friendly alternative to conventional testing; in clinical and other field settings, especially those in resource-limited settings.

Standardised protocol for a prospective international multicentre clinical-based evaluation of point-of-care tests for the screening of genital and extragenital chlamydial and gonococcal infections in men who have sex with men and for the screening of genital chlamydial, gonococcal and Trichomonas vaginalis infections in at risk women.

INTRODUCTION: In 2016, WHO estimated there were roughly 374 million new infections among adults of the following four curable sexually transmitted infections (STIs): chlamydia (caused by Chlamydia trachomatis (CT)), gonorrhoea (Neisseria gonorrhoeae (NG)), syphilis (Treponema pallidum) and trichomoniasis (Trichomonas vaginalis (TV)). Accurate point-of-care tests (POCTs) for screening of genital and extragenital CT, NG and TV infections are of great value and have been developed during recent decade. Several tests are commercially available and have shown encouraging performance compared with 'gold-standard' reference tests in laboratory-based studies. However, there is limited data on their clinical performance, including at the POC. Key populations, such as men who have sex with men (MSM), are at higher risk of these STIs at genital and extragenital sites and these STIs are often asymptomatic, especially in extragenital sites and in women. We will conduct a clinical-based evaluation to assess the performance characteristics and acceptability to end-users of molecular-based diagnostic technology for POC/near patient use of the Xpert CT/NG (Cepheid, Sunnyvale, California, USA) test for screening of genital, anorectal and pharyngeal CT and NG infections in MSM and the Xpert CT/NG and Xpert TV (Cepheid, Sunnyvale, California, USA) for screening of genital CT, NG and TV among women at risk for these STIs compared with gold-standard reference nucleic acid amplification tests. This master protocol outlines the overall research approach that will be used in seven countries. METHOD AND ANALYSES: Consecutive MSM and women at risk presenting at the clinical sites in high, and low- and middle-income countries will be enrolled. The POCTs to be evaluated are Xpert CT/NG and Xpert TV. All procedures will be carried out by trained healthcare staff and tests performed in strict accordance with the manufacturer's instructions. The sensitivity, specificity, positive and negative predictive values for each POCT will be calculated. The study is ongoing with recruitment expected to be completed in all countries by mid-2022 to late-2022. ETHICS AND DISSEMINATION: Prior to enrolment, this core protocol was independently peer-reviewed and approved by the research project review panel (RP2) of the WHO Department of Sexual and Reproductive Health and Research and by the WHO Ethics Review Committee (ERC). The core protocol has been slightly adapted accordingly to individual countries and adaptations approved by both RP2 and ERC, as well as all relevant institutional review boards at each participating site. Results will be disseminated through peer-reviewed journals and presented at relevant national/international conferences.