A field evaluation of a new molecular-based point-of-care test for chlamydia and gonorrhoea in remote Aboriginal health services in Australia

Sexual Health ◽  
2015 ◽  
Vol 12 (1) ◽  
pp. 27 ◽  
Author(s):  
Louise M. Causer ◽  
Belinda Hengel ◽  
Lisa Natoli ◽  
Annie Tangey ◽  
Steven G. Badman ◽  
...  
Keyword(s):  
Health Services ◽  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
Field Evaluation ◽  
Aboriginal Health ◽  
Ease Of Use ◽  
Nucleic Acid Amplification ◽  
Specimen Preparation ◽  
Sexually Transmissible Infections

Background Point-of-care (POC) tests could be important public health tools in settings with treatment delays and high rates of sexually transmissible infections (STIs). Use is limited due to suboptimal performance. The performance and ease-of-use of a new molecular-based POC test for simultaneous detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was assessed, alongside two single-organism immunochromatographic tests (ICT). Methods: The evaluation occurred between May 2012 and March 2013 during community STI screens in two remote Aboriginal health services. Urine was tested with the GeneXpert®CT/NG and if sufficient volume, also with Diaquick CT and Gonorrhoea Card. The gold standard comparison was laboratory nucleic acid amplification testing (NAAT). Operational characteristics were also assessed. Results: Among 198 samples, GeneXpert CT sensitivity and specificity was 100% [95% confidence intervals (CI): 75.9–100] and 99.5% (95% CI: 96.5–100), and NG was 100% (95% CI: 96.5–100) and 100% (95% CI: 97.5–100), respectively. Among a sample subset, Diaquick CT (n = 104) sensitivity and specificity was 27.3% (95% CI: 7.3–60.7) and 66.7% (95% CI: 12.5–98.2), and Gonorrhoea Card (n = 29), was 66.7% (95% CI: 12.5–98.2) and 76.9% (95% CI: 56.0–90.2), respectively. GeneXpert required 1 mL of urine, four steps, 1 min specimen preparation and 90 min to result. ICTs required 15 mL of urine, eight steps, 18 min preparation and 10–15 min to result. Conclusion: The accuracy and operational benefits of GeneXpert CT/NG make it very suitable in these settings where delays to treatment are encountered.

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

2018 ◽  
Vol 94 (5) ◽  
pp. 340-345 ◽  
Author(s):  
Louise M Causer ◽  
Rebecca J Guy ◽  
Sepehr N Tabrizi ◽  
David M Whiley ◽  
David John Speers ◽  
...  
Keyword(s):  
Primary Care ◽  
Health Services ◽  
Point Of Care ◽  
Community Health Services ◽  
Nucleic Acid Amplification ◽  
Molecular Test ◽  
Middle Income ◽  
Healthcare Settings ◽  
Diagnostic Test Evaluation ◽  
Low Middle Income Countries

ObjectivesA new molecular test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) (GeneXpert CT/NG) has been demonstrated to be as accurate as conventional nucleic acid amplification tests (NAAT), but performance has not been evaluated in routine primary care, performed at the point of care by clinicians. We aimed to examine its diagnostic performance when used by clinicians in remote community health services in Australia with high prevalences of CT and NG infection. The trial was registered with the Australian and New Zealand Clinical Trials Registry (#12613000808741)MethodsAt 12 health services, training was provided to 99 clinicians in the use of the GeneXpert CT/NG assay who tested specimens from all patients undergoing STI screening. Specimens were also sent in parallel for conventional laboratory-based NAATs and the concordance of results was evaluated.ResultsClinicians conducted 2486 tests: CT concordance was 99.4% (95% CI 99.1 to 99.7) with a positive concordance of 98.6% (95% CI 95.9 to 99.7) and negative concordance of 99.5% (95% CI 99.1 to 99.8); NG concordance was 99.9% (95% CI 99.7 to 100.0) with a positive concordance of 100.0% (95% CI 97.5 to 100.0) and negative concordance of 99.9% (95% CI 99.7 to 100.0).ConclusionsIn this first study reporting routine point-of-care use of GeneXpert CT/NG by primary care clinicians, we found excellent concordance with conventional NAATs. The use of the GeneXpert CT/NG at the point of care could potentially transform management and control of these infections in many endemic settings, including low/middle-income countries.

scholarly journals Simultaneous Detection of Different Zika Virus Lineages via Molecular Computation in a Point-of-Care Assay

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 714 ◽  
Author(s):  
Sanchita Bhadra ◽  
Miguel Saldaña ◽  
Hannah Han ◽  
Grant Hughes ◽  
Andrew Ellington
Keyword(s):  
Zika Virus ◽  
Point Of Care ◽  
Logic Gate ◽  
Simultaneous Detection ◽  
Direct Analysis ◽  
Ease Of Use ◽  
Molecular Diagnostic ◽  
Specificity And Sensitivity ◽  
Isothermal Assay ◽  
Fail Safe

We have developed a generalizable “smart molecular diagnostic” capable of accurate point-of-care (POC) detection of variable nucleic acid targets. Our isothermal assay relies on multiplex execution of four loop-mediated isothermal amplification reactions, with primers that are degenerate and redundant, thereby increasing the breadth of targets while reducing the probability of amplification failure. An easy-to-read visual answer is computed directly by a multi-input Boolean OR logic gate (gate output is true if either one or more gate inputs is true) signal transducer that uses degenerate strand exchange probes to assess any combination of amplicons. We demonstrate our methodology by using the same assay to detect divergent Asian and African lineages of the evolving Zika virus (ZIKV), while maintaining selectivity against non-target viruses. Direct analysis of biological specimens proved possible, with crudely macerated ZIKV-infected Aedes aegypti mosquitoes being identified with 100% specificity and sensitivity. The ease-of-use with minimal instrumentation, broad programmability, and built-in fail-safe reliability make our smart molecular diagnostic attractive for POC use.

scholarly journals Multisite Laboratory Evaluation of a Dual Human Immunodeficiency Virus (HIV)/Syphilis Point-of-Care Rapid Test for Simultaneous Detection of HIV and Syphilis Infection

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Claire C. Bristow ◽  
Yaw Adu-Sarkodie ◽  
Raphael O. Ondondo ◽  
Elizabeth Anne Bukusi ◽  
Claver Anoumou Dagnra ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Sensitivity And Specificity ◽  
Solid Phase ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
Laboratory Evaluation ◽  
Test Results ◽  
Immunodeficiency Virus ◽  
Test Component ◽  
Rapid Tests

Abstract Background.  Recently, test developers have created rapid point-of-care tests that can simultaneously detect multiple infections within the same specimen using a single device. The SD BIOLINE Duo HIV/Syphilis rapid point-of-care test uses a solid-phase immunochromatographic assay to detect immunoglobulin (Ig)G, IgM, and IgA antibodies to human immunodeficiency virus (HIV)-specific antigens (HIV-1 gp41, sub O, HIV-2 gp36) and recombinant Treponema pallidum antigen (17 kDa) in human serum. This study was a multisite laboratory-based evaluation of the performance of SD BIOLINE HIV/Syphilis Duo test using previously characterized sera in 6 countries. Methods.  Laboratories in Ghana, Mexico, Laos, Togo, Kenya, and Myanmar participated in the evaluation during 2012–2013. Each site characterized sera using T pallidum particle agglutination assay or T pallidum hemagglutination assay and HIV enzyme immunoassay, Western blot, and/or HIV antibody rapid tests. Those gold standard test results were compared with SD BIOLINE Duo test results. We calculated the sensitivity and specificity of test performance and used the exact binomial method to calculate 95% confidence intervals (CIs). Results.  The sensitivity and specificity for the HIV antibody test component (n = 2336) were estimated at 99.91% (95% CI, 99.51% and 100%) and 99.67% (95% CI, 99.16% and 99.91%), respectively. For the T pallidum test component (n = 2059), the sensitivity and specificity were estimated at 99.67% (95% CI, 98.82% and 99.96%) and 99.72% (95% CI, 99.29% and 99.92%), respectively. Conclusions.  The sensitivity and specificity of the SD BIOLINE HIV/Syphilis Duo test were consistently high across sera specimens from 6 countries around the world. Dual rapid tests should be considered for improved HIV and syphilis screening coverage.

scholarly journals Field evaluation of a prototype tuberculosis lipoarabinomannan lateral flow assay on HIV-positive and HIV-negative patients

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254156
Author(s):  
John T. Connelly ◽  
Alfred Andama ◽  
Benjamin D. Grant ◽  
Alexey Ball ◽  
Sandra Mwebe ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Field Evaluation ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Hiv Positive ◽  
Clinical Sensitivity ◽  
Cell Counts ◽  
Significant Difference ◽  
Hiv Negative

Detection of tuberculosis at the point-of-care (POC) is limited by the low sensitivity of current commercially available tests. We describe a diagnostic accuracy field evaluation of a prototype urine Tuberculosis Lipoarabinomannan Lateral Flow Assay (TB-LAM LFA) in both HIV-positive and HIV-negative patients using fresh samples with sensitivity and specificity as the measures of accuracy. This prototype combines a proprietary concentration system with a sensitive LFA. In a prospective study of 292 patients with suspected pulmonary tuberculosis in Uganda, the clinical sensitivity and specificity was compared against a microbiological reference standard including sputum Xpert MTB/RIF Ultra and solid and liquid culture. TB-LAM LFA had an overall sensitivity of 60% (95%CI 51–69%) and specificity of 80% (95%CI 73–85%). When comparing HIV-positive (N = 86) and HIV-negative (N = 206) patients, there was no significant difference in sensitivity (sensitivity difference 8%, 95%CI -11% to +24%, p = 0.4351) or specificity (specificity difference -9%, 95%CI -24% to +4%, p = 0.2051). Compared to the commercially available Alere Determine TB-LAM Ag test, the TB-LAM LFA prototype had improved sensitivity in both HIV-negative (difference 49%, 95%CI 37% to 59%, p<0.0001) and HIV-positive patients with CD4+ T-cell counts >200cells/μL (difference 59%, 95%CI 32% to 75%, p = 0.0009). This report is the first to show improved performance of a urine TB LAM test for HIV-negative patients in a high TB burden setting. We also offer potential assay refinement solutions that may further improve sensitivity and specificity.

scholarly journals Comparison of 3 Nucleic Acid Amplification Tests and a Rapid Antigen Test with Culture for the Detection of Group A Streptococci from Throat Swabs

2019 ◽  
Vol 4 (2) ◽  
pp. 164-169 ◽  
Author(s):  
Kyle G Parker ◽  
Sumanth Gandra ◽  
Scott Matushek ◽  
Kathleen G Beavis ◽  
Vera Tesic ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Predictive Value ◽  
Bacterial Culture ◽  
Group A Streptococcus ◽  
Point Of Care ◽  
High Sensitivity ◽  
Ease Of Use ◽  
Nucleic Acid Amplification ◽  
Gold Standard Method ◽  
Group A

Abstract Background Recently, the US Food and Drug Administration cleared 3 nucleic acid amplification test (NAAT) assays for detection of Streptococcus pyogenes [group A Streptococcus (GAS)] in pharyngeal specimens. However, there are limited studies evaluating the performance of these NAAT assays. Methods We compared the results of 3 NAATs (cobas Liat, Luminex Aries, and Cepheid Xpert Xpress) and a rapid antigen assay (Quidel QuickVue in-line strep A) with the accepted gold standard method, bacterial culture. Results Sixty-eight throat swab specimens collected between August and October 2017 were tested. Compared to bacterial culture, the sensitivities, specificities, positive predictive value, and negative predictive value for detecting GAS were as follows: cobas Liat: 100%, 97.4%, 96.7%, and 100%; Cepheid Xpert: 100%, 97.4%, 96.7%, and 100%; Luminex Aries: 95.2%, 100%, 100%, and 95.5%. The Quidel QuickVue in-line strep A assay showed poor sensitivity, detecting only 5.2% of culture-positive specimens. Conclusion The 3 NAATs have high sensitivity when compared with bacterial culture for detection of GAS. With rapid turnaround time and ease of use, these tests can be considered as reliable point-of-care tests for the diagnosis of GAS, replacing the need for back-up culture.

scholarly journals O22.6 Field Evaluation of Three Point-Of-Care Tests For Chlamydia and Gonorrhoea in Remote Health Services in Australia

2013 ◽  
Vol 89 (Suppl 1) ◽  
pp. A70.2-A70
Author(s):  
L M Causer ◽  
B Hengel ◽  
L Natoli ◽  
A Tangey ◽  
S Badman ◽  
...  
Keyword(s):  
Health Services ◽  
Point Of Care ◽  
Field Evaluation ◽  
Point Of Care Tests ◽  
Remote Health

scholarly journals Scaling up sexually transmissible infections point-of-care testing in remote Aboriginal and Torres Strait Islander communities: healthcare workers’ perceptions of the barriers and facilitators

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Lise Lafferty ◽  
Kirsty Smith ◽  
Louise Causer ◽  
Kelly Andrewartha ◽  
David Whiley ◽  
...  
Keyword(s):  
Health Services ◽  
Patient Engagement ◽  
Healthcare Workers ◽  
Torres Strait Islander ◽  
Point Of Care ◽  
Scaling Up ◽  
Point Of Care Testing ◽  
Sti Testing ◽  
Sexually Transmissible Infections ◽  
Torres Strait

Abstract Background Sexually transmissible infections (STIs), such as gonorrhoea and chlamydia, are highly prevalent, particularly in remote Aboriginal and Torres Strait Islander communities in Australia. In these settings, due to distance to centralised laboratories, the return of laboratory test results can take a week or longer, and many young people do not receive treatment, or it is considerably delayed. Point-of-care testing (POCT) provides an opportunity for same day diagnosis and treatment. Molecular POC testing for STIs was available at 31 regional or remote primary health care clinic sites through the Test-Treat-And-GO (TANGO2) program. This qualitative study sought to identify barriers and facilitators to further scaling up STI POCT in remote Aboriginal communities within Australia. Methods A total of 15 healthcare workers (including nurses and Aboriginal health practitioners) and five managers (including clinic coordinators and practice managers) were recruited from remote health services involved in the TTANGO2 program to participate in semi-structured in-depth interviews. Health services’ clinics were purposively selected to include those with high or low STI POCT uptake. Personnel participants were selected via a hybrid approach including nomination by clinic managers and purposive sampling to include those in roles relevant to STI testing and treatment and those who had received TTANGO2 training for POCT technology. Milat’s scaling up guide informed the coding framework and analysis. Results Acceptability of STI POCT technology among healthcare workers and managers was predominantly influenced by self-efficacy and perceived effectiveness of POCT technology as well as perceptions of additional workload burden associated with POCT. Barriers to integration of STI POCT included retention of trained staff to conduct POCT. Patient reach (including strategies for patient engagement) was broadly considered an enabler for STI testing scale up using POCT technology. Conclusions Remote healthcare clinics should be supported by both program and clinic management throughout scaling up efforts to ensure broad acceptability of STI POCT as well as addressing local health systems’ issues and identifying and enhancing opportunities for patient engagement.

Trends in Diagnosis for Active Tuberculosis Using Nanomaterials

2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park
Keyword(s):  
Sensitivity And Specificity ◽  
High Efficiency ◽  
Point Of Care ◽  
High Sensitivity ◽  
Signs And Symptoms ◽  
Diagnostic Methods ◽  
Advantages And Disadvantages ◽  
Treatment And Prevention ◽  
Clinical Tools ◽  
Diagnostic Applications

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.

scholarly journals Microfluidics-Based Plasmonic Biosensing System Based on Patterned Plasmonic Nanostructure Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 826
Author(s):  
Yanting Liu ◽  
Xuming Zhang
Keyword(s):  
Plasmon Resonance ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Microfluidic Chips ◽  
Label Free ◽  
Plasmonic Nanostructure ◽  
Point Of Care Diagnostics ◽  
Surface Enhanced Raman ◽  
Nanostructure Arrays

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.

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