Performance and operational characteristics of point-of-care tests for the diagnosis of urogenital gonococcal infections

Abstract

background In 2012, there was an estimated 78 million new cases of gonorrhoea globally. Untreated infection may lead to reproductive and neonatal morbidity and facilitate HIV transmission. Diagnosis and treatment are a priority for control and prevention, yet use of point-of-care tests (POCTs) for Neisseria gonorrhoeae (NG) is limited. Objectives To review the performance and operational characteristics of NG POCTs for diagnosis of urogenital gonorrhoea. Methods We compiled and synthesised findings from two separate systematic reviews which included evaluations published until August 2015. results Six tests were included: five were immunochromatographic tests (ICTs) or optical immunoassay (OIAs) based on antigen detection; with 5-7 steps and results in 25-40 min, and one (GeneXpert CT/NG) was a 'near-patient test' based on nucleic acid amplification technique (NAAT); with three steps, electricity required, and results in 90 min. When compared with laboratory-based NAATs as the reference tests, sensitivities of ICT and OIA-based POCTs ranged from 12.5% to 70% when cervical/vaginal swabs were tested. Specificities ranged from 89% to 99.8%. The near-patient NAAT had sensitivities of >95% and specificities of >99.8% consistently across all specimen types (urine, cervical and vaginal swabs). conclusions Based on a limited number of evaluations, antigen detection POCTs for NG lacked sufficient sensitivity to be used for screening. A near-patient NAAT has acceptable performance, only involved a few steps, but needs electricity, a temperature-controlled environment and has a 90 min run time. To achieve wider scale up of NG POCTs, we need strong evidence of cost-effectiveness, which should inform guidelines and ultimately increase test development, demand and reduce costs.

REASSURED diagnostics to inform disease control strategies, strengthen health systems and improve patient outcomes

“…Malaria RDTs are an exception to these drawbacks in that the parasites are present in large quantities in blood and no pre-processing or concentration steps are required. For most antigen detection POC tests, the low sensitivity may be due to low concentration of target antigens, inefficiency of extraction or limited optimization of reagents, which has hampered chlamydia and gonorrhoea tests 52,53 . However, Gift et al showed that rapid chlamydia tests with a sensitivity of 65% can lead to more infected patients being treated compared to NATs, which require patients to return for their test results 54 .…”

A paperfluidic platform to detect Neisseria gonorrhoeae in clinical samples

“…As a result, the United States Centers for Disease Control urges clinics to use point-of-care (POC) tests to ensure that high-risk patients receive treatment in the same visit (Johnson et al 2002). Despite some progress in developing immunoassay based rapid diagnostic tests (RDTs) and near-patient qPCR systems, a POC NG diagnostic that combines high specificity and sensitivity with low-cost is not yet available (Gaydos et al 2013; Greer and Wendel 2008; Guy et al 2017). While manufacturer reported sensitivities are as high as 98.3% for both urethral and vaginal swab samples (Huppert et al 2010; Cortez 2006), clinical studies comparing multiple RDTs to qRT-PCR have shown RDT sensitivities of only 54% for vaginal swab samples (Alary et al 2006).…”

Molecular test for chlamydia and gonorrhoea used at point of care in remote primary healthcare settings: a diagnostic test evaluation

“…Until recently, the only commercially available POC tests for CT and NG were based on lateral flow platforms which are inexpensive but require numerous specimen preparation steps7 and have very poor sensitivity 7 8. In 2013, the GeneXpert CT/NG assay (Cepheid, Sunnyvale, CA) became the first nucleic acid-based test for CT/NG available for POC use.…”