Rapid Point Of Care Test Research Articles

A sample-to-answer digital microfluidic multiplexed PCR system for syndromic pathogen detection in respiratory tract infection.

Timely identification of infectious pathogens is crucial for the accurate diagnosis, management, and treatment of syndromic respiratory diseases. Nevertheless, the implementation of rapid, precise, and automated point-of-care testing (POCT) remains a significant challenge. This study introduces an advanced digital microfluidic (DMF) POCT testing system designed for the rapid molecular syndromic testing of multiple respiratory pathogens from a single untreated sample. The system seamlessly integrates magnetic beads-based nucleic acid extraction, PCR amplification, and real-time fluorescence analysis in an automatic run, facilitating sample-to-answer detection within 80 min. It accommodates various sample types, including nasopharyngeal swabs, oropharyngeal swabs, bronchoalveolar lavage fluid, and sputum. A facile sample loading method has been developed to reduce hands-on time to less than 1 min. The system exhibits high sensitivity (200-628 copies per mL) for 15 pathogens and has the capacity for up to 32 multiplexed tests per run. Validation with 255 clinical samples confirms its high sensitivity and specificity. The DMF-based system significantly reduces manual labour, enhances rapid POCT for respiratory infections, and, with optimized manufacturing processes, lowers costs for large-scale production. The system can be applied and improve clinical management near the patients as well as in resource-limited settings.

Syphilis Point of Care Rapid Test and Immediate Treatment Evaluation (SPRITE) study: a mixed-methods implementation science research protocol of eight public health units in Ontario, Canada

IntroductionUrgent, tailored and equitable action is needed to address the alarming rise in syphilis rates in Canada. In the last decade, the rates of infectious syphilis have increased by 345%...

Long-Term Stable Eu2O3-Loaded Dendritic Mesoporous Silica Nanoprobes with Coordination-Enhanced Photoluminescence for Ultrasensitive Lateral Flow Immunoassay.

Inorganic lanthanide nanomaterials as photoluminescent biolabels have attracted increasing attention due to their superior physicochemical properties. However, unstable conjugation of inorganic lanthanide nanomaterials with biological function units (such as antibodies) induces instability of conjugated complexes in aqueous solution, limiting their clinical application. In this study, we developed a rapid point-of-care testing (POCT) platform strategy based on coordination-enhanced time-resolved luminescence of specially nanostructural lanthanide particles for lateral flow immunoassay (CE-TRFIA). This strategy integrates a nanoprobe via a dendritic mesoporous silica nanosphere (DMSN) loading a large amount of ultrasmall amorphous europium oxide (Eu2O3) nanoparticles, which rapidly dissolve to release Eu3+ cations under neutral pH value and form luminescent complexes with photosensitizers (such as β-NTA and TOPO) in an LFIA system. This innovative strategy achieves high-sensitivity detection and long-term stability primarily through high-loading probes, excellent dissolution enhancement, stable covalent coupling, and time-resolved detection. With Procalcitonin (PCT) antigen selected as the detection sample, this approach achieves high-sensitivity detection of PCT with a limit of detection (LoD) as low as 1.9 pg/mL, significantly lower than that of commercial LFIA (0.1 ng/mL), and excellent clinical correlation (r = 0.989). The method offers chemiluminescence-level sensitivity without the need for large instruments while retaining the real-time detection characteristics of LFIA. Our results highlight CE-TRFIA as a highly sensitive, specific, and rapid POCT solution for detecting low-abundance biomarkers such as PCT, enhancing the diagnostic capabilities of traditional LFIA and offering significant potential for ultrasensitive and rapid clinical diagnostics.

Drip-Dry Strategy Assisted Blu-Ray Disc Biosensor for Fast Point of Care Testing.

Discs and numerous other consumer products have been developed for point of care testing (POCT) to replace traditional large and expensive biochemical devices in certain scenarios. Herein, we propose a drip-dry strategy (2D strategy) assisted Blu-ray disc (BD) biosensor, termed BDB, for rapid and portable POCT within 30 min with the cost of a single test < $1. The platform utilizes the covered area formed by the deposition of the substance to be measured on the activated BD surface after the evaporation of water and realizes the quantitative detection of the target through the error readout of free disc quality diagnosis software. As a proof of concept, we first demonstrated the feasibility of direct quantitative detection of substances in solution in a single system through the detection of pure proteins avoiding colorimetric reagent used in traditional optical detection. For the complex mixed systems, we then innovatively utilize the principle that soluble targets promote/inhibit the dissolution of insoluble precipitates to achieve specific detection of targets and successfully apply BDB to the indirect quantitative detection of glutathione (GSH) with LOD of 0.447 mM in the range of 2-16 mM and organophosphorus pesticides (OPs) with LOD of 2.122 × 10-7 M in the range of 1.289 × 10-7-1.289 × 10-4 M. The BDB is widely applicable, easy to operate, and less time-consuming, which is anticipated to provide an alternative method for early, on-site detection or screening.

Transforming respiratory tract infection diagnosis in the kingdom of saudi arabia through point-of-care testing: A white paper for policy makers

With the evident increased prevalence of respiratory tract infections (RTIs) such as Respiratory Syncytial Virus (RSV), influenza, Group A Streptococcus (GAS), and COVID-19, the conventional diagnostic methods are considered sub-optimal in providing timely management to patients in the Kingdom of Saudi Arabia (KSA). Gaps in current diagnostics are magnified by the Kingdom's unique demographic composition, comprising 11.9 million foreign workers, and the annual influx of over 10 million pilgrims. Current gaps in timely diagnosis leads to delays in treatment, misuse of antibiotics, and protracted hospital stays, subsequently compromising patient care, and escalating healthcare costs. KSA healthcare stakeholders suggest that the integration of rapid molecular Point-of-Care Testing (POCT) into the Kingdom's healthcare infrastructure is an absolute necessity. This publication serves as an urgent call for action aimed at healthcare policymakers in Saudi Arabia, to review the existing diagnostic challenges and include rapid POCTs in the Saudi healthcare strategy for respiratory infections.

Loop-mediated isothermal amplification (LAMP) for detection of atypical enterovirus D68 strain VR-1197

A method that has rapidly evolved for detection of viral pathogens are loop-mediated isothermal amplification (LAMP) assays. The available LAMP assays usually target the most common viral strains, including enteroviruses, but for the atypical enterovirus D68 strain VR-1197 this method has not yet been developed. Enterovirus D68 are known for severe respiratory distress in children, and atypical strains are less likely to be detected by traditional methods. This study targets the atypical EVD68 strain VR-1197 and have developed a rapid detection method saving time when differentiating enterovirus strains. This study present method development and review the sensitivity and specificity compared to traditional RT-qPCR, and wet lab cross reactivity with other airway pathogens. The EVD68 VR-1197 assay can be a rapid POC (Point of care) test for atypical EVD68 VR-1197 and have the potential as reliable detection method with minimal technological requirements.

Salivary CD44 and Total Protein Levels to Detect Risk for Oral and Oropharyngeal Cancer Recurrence

Oral and oropharyngeal cancer have low survival rates, and incidence continues to increase. To determine whether soluble CD44 and total protein (TP) are useful for monitoring head and neck cancer recurrence, either used in a point-of-care (POC) test or as individual laboratory-based biomarkers. This multi-institutional nonrandomized clinical trial testing a novel diagnostic/screening assay took place across the University of California, San Diego; Johns Hopkins University; the Greater Baltimore Medical Center; New York University; and the San Diego Veterans Affairs Hospital. Patients with newly biopsy-proven, untreated oral cavity and oropharyngeal cancer were enrolled. Patients were enrolled April 2017 to April 2019, and data were analyzed December 2022 to June 2023. POC salivary oral rinse test. Oral rinses were collected at pretreatment baseline and 3, 6, 12, and 18 months after completion of therapy; participants were then followed up for 3 years to define disease status. Associations of baseline characteristics with a positive test were evaluated by Fisher exact test. The association of a positive value on the CD44 or TP test with progression-free survival was evaluated in an adjusted multivariable proportional hazards model. Of 172 patients enrolled, the mean (SD) age was 62.5 (10.2) years, and 122 (70.9%) identified as male. Additionally, 92 patients (53.3%) had never smoked, 99 (57.6%) formerly or currently drank alcohol, and 113 (65.7%) presented with oropharyngeal cancers, which were positive for human papillomavirus in 95 (84.1%). Tumor site was associated with test results at baseline; patients with oral cavity cancer had a higher baseline positive POC test rate (47 of 51 [92.2%]) compared to patients with oropharyngeal cancer (85 of 110 [77.3%]). Using Cox regression models with CD44 or TP level as a time-varying covariate, a higher CD44 level showed a statistically significant association with a higher hazard of recurrence (hazard ratio, 1.06; 95% CI, 1.00-1.12), though the TP level was not statistically significant. In multivariate adjusted analysis, higher CD44 and TP levels were associated with increased hazard ratios of recurrence of 1.13 (95% CI, 1.04-1.22) and 3.51 (95% CI, 1.24-9.98), respectively. In this multi-institutional nonrandomized clinical trial of an assay, posttreatment longitudinal monitoring for elevated salivary CD44 and TP levels using an enzyme-linked immunosorbent assay-based laboratory test identified patients at increased risk of future cancer recurrence. The CD44 and TP rapid POC test holds some promise, but further development is needed for this indication. ClinicalTrials.gov Identifier: NCT03148665.

Aluminium-copper-mesoporous silica molecular sieve-enabled dual-signal point-of-care aptasensor with integrated temperature and multicolor readout

Dual-signal point-of-care testing (POCT) method relying on multicolor changes have demonstrated a promising improvement in performance. In this work, we have developed a highly sensitive and rapid POCT method for detecting aflatoxin B1 (AFB1), utilizing a dual-signal readout mode based on temperature and multicolor changes. A synthetic enzyme mimics, Al-Cu-Santa Barbara Amorphous material (Al-Cu-SBA), has been used to enable the dual-signal changes of gold nanobipyramids (Au NBPs) for the first time. Specifically, the aptamer was immobilized on magnetic beads, facilitating hybridization with complementary strands functionalized with Al-Cu-SBA and hence forming double-stranded DNA. Upon introducing AFB1 into the system, it bound to the aptamer chain, resulting in the release of Al-Cu-SBA into solution. The liberated Al-Cu-SBA was subsequently collected and used to oxidize 3, 3′, 5, 5′-tetramethylbenzidine (TMB). The oxidized TMB was used to etch Au NBPs, inducing significant color changes. Meanwhile, by leveraging the photothermal properties of Au NBPs, we observed a temperature difference generated upon exposure to infrared laser irradiation. This method exhibited a linear range from 0.5 μg·mL−1 to 100 μg·mL−1, with a detection limit of 0.167 μg·mL−1. The method’s applicability was extended to successfully detect AFB1 in both peanut oil and milk samples. Given the application of enzyme mimics and the dual-signal readout integrating temperature and multicolor changes, our study successfully overcomes the limitations inherent in traditional biological enzyme-based methods and the conventional single-signal readout approach. Additionally, it surpasses the limitations associated with dual-signal readout systems that rely solely on monochromatic colorimetric analysis.

Does the Addition of Point-of-Care Testing Alter Antibiotic Prescribing Decisions When Patients Present with Acute Sore Throat to Primary Care? A Prospective Test of Change.

Accurate clinical diagnosis of patients presenting to primary care settings with acute sore throat remains challenging, often resulting in the over-prescribing of antibiotics. Using point-of-care tests (POCTs) to differentiate between respiratory infections is well-accepted, yet evidence on the application within primary care is sparse. We assessed the application of testing patients (n = 160) from three family practices with suspected Streptococcal infections using rapid molecular tests (ID NOW Strep A2, Abbott). In addition to comparing clinical evaluation and prescription rates with either usual care or testing, patients and staff completed a questionnaire about their experience of molecular POCT in primary care. The immediate availability of the result was important to patients (100%), and staff (≈90%) stated that molecular testing improved the quality of care. Interestingly, only 22.73% of patients with a Centor score > 2 tested positive for Strep A and, overall, less than 50% of Centor scores 3 and 4 tested positive for Strep A with the ID NOW testing platform. The addition of rapid molecular POCTs to clinical assessment resulted in a 55-65% reduction in immediate and deferred antibiotic prescriptions. The intervention was popular with patients and medical staff but was associated with increased cost and a longer appointment length.

Implementation of point-of-care molecular testing for respiratory viruses in congregate living settings.

To implement and evaluate a point-of-care (POC) molecular testing platform for respiratory viruses in congregate living settings (CLS). Prospective quality improvement study. Seven CLS, including three nursing homes and four independent-living facilities. Residents of CLS. A POC platform for COVID-19, influenza A and B, and respiratory syncytial virus was implemented at participating CLS from December 1, 2022 to April 15, 2023. Residents with respiratory symptoms underwent paired testing, with respiratory specimens tested first with the POC platform and then delivered to an off-site laboratory for multiplex respiratory virus panel (MRVP) polymerase chain reaction (PCR) as per standard protocol. Turn-around time and diagnostic accuracy of the POC platform were compared against MRVP PCR. In an exploratory analysis, time to outbreak declaration among participating CLS was compared against a convenience sample of 19 CLS that did not use the POC platform. A total of 290 specimens that underwent paired testing were included. Turn-around time to result was significantly shorter with the POC platform compared to MRVP PCR, with median difference of 36.2 hours (interquartile range 21.8-46.4 hours). The POC platform had excellent diagnostic accuracy compared to MRVP PCR, with area under the curve statistic of .96. Time to outbreak declaration was shorter in CLS that used the POC platform compared to CLS that did not. Rapid POC testing platforms for respiratory viruses can be implemented in CLS, with high diagnostic accuracy, expedited turn-around times, and shorter time to outbreak declaration.

Equivocal diagnostics: Making a 'good' point-of-care test for elimination in global health.

What is a diagnostic test for? We might assume the answer to this question is straightforward. A good test would help identify what disease someone suffers from, assist health providers to determine the correct course of treatment and/or enable public health authorities to know and intervene in health at the level of the population. In this article, we show that what a specific diagnostic test is for, the value it holds for different actors, and what makes it good, or not, is often far from settled. We tell the story of the development and design of a rapid antibody test for onchocerciasis, or river blindness, tracking multiple iterations of the device through three configurational moments in the framing of onchocerciasis disease and reshaping of the global health innovation ecosystem. Efforts to build that ecosystem for diagnostics are often premised on the notion that public health needs for diagnostics are pre-given and stable; the challenge is seen to be how to incentivize investment and find a customer base for diagnostics in under-resourced settings. By contrast, we show that for any disease, diagnostic needs are both multiple and constantly in flux, and are unlikely to be met by a single, stand-alone product. In the case of the onchocerciasis Ov-16 rapid test, the failure to recognize and address the multiplicity and instability of diagnostic needs in the innovation process resulted in the development of a rapid point of care test that might be manufactured, procured and used, but is unloved by public health experts and commercial manufacturers alike. The equivocal value of the onchocerciasis rapid test, we suggest, reveals the inadequacy of the current global health innovation ecosystem for developing diagnostic 'goods'.

Evaluation of Glial Fibrillary Acidic Protein and Ubiquitin C-Terminal Hydrolase-L1 Using a Rapid Point of Care Test for Predicting Head Computed Tomography Lesions After Mild Traumatic Brain Injury in a Dutch Multi-Center Cohort.

Mild traumatic brain injury (mTBI) is a common condition seen in emergency departments worldwide. Blood-based biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) are recently U.S. Food and Drug Administration-approved for the prediction of intracranial lesions on head computed tomography (CT) scans in mTBI. We evaluated the diagnostic performance of GFAP and UCH-L1 in a Dutch cohort using the i-STAT TBI assay. In a multi-center observational study, we enrolled 253 mTBI patients. Head CT scans were scored using the Marshall classification system. Logistic regression models were used to assess the contribution of biomarkers and clinical parameters to diagnostic performance. Detection of UCH-L1 and GFAP resulted in a sensitivity of 97% and specificity of 19% for CT positivity in mTBI patients, along with a negative predictive value of 95% (88-100%) and a positive predictive value of 27% (21-33%). Combining biomarker testing with loss of consciousness and time to sample increased specificity to 46%. Combined testing of UCH-L1 and GFAP testing resulted in possibly more unnecessary CT scans compared with GFAP testing alone, with only limited increase in sensitivity. This study confirmed high sensitivity of GFAP and UCH-L1 for CT abnormalities in mTBI patients using the i-STAT TBI test. The results support the potential use of GFAP and UCH-L1 as tools for determining the indication for CT scanning in mTBI patients, possibly offering a cost- and time-effective approach to management of patients with mTBI. Prospective studies in larger cohorts are warranted to validate our findings.

Smartphone and handheld fluorometer enable rapid point of care testing of Escherichia coli in urinary tract infections via specific proteolytic cleavage and cascade amplifications

Culture-free, rapid, and ultrasensitive quantification of Escherichia coli (E. coli) is urgently needed to diagnose clinical urinary tract infections (UTIs), especially point-of-care testing (POCT). Herein, a homogeneous sensitive multi-modal (fluorometer, smartphone, and self-developed handheld fluorometer) assay was developed to detect E. coli within 30 min, and nanoscale luminescent cadmium telluride quantum dots (CdTe QDs) were employed as signal reporters. E. coli outer membrane protease T (OmpT) is a biomarker for the specific proteolytic cleavage of peptides. p-Aminophenol (PAP), generated by leucine aminopeptidase (LAP) via secondary cleavage, was used to reduce Ag+. Cascade amplifications included Ag+ and copper sulfide nanoparticles (CuS NPs) to release Cu2+, CdTe QDs, and Cu2+/CuS NPs, which can ensure detection sensitivity. The method achieved single bacterium detection with great stability and selectivity. The fluorometer, handheld fluorometer and smartphone red-green-blue (RGB) value-based modes were determined to be 50, 15, and 15 clinical urine samples, respectively. The findings were consistent with clinical culture counting, and an area under the curve (AUC) of 0.95 with 90% sensitivity and 100% specificity was achieved. Overall, this OmpT-based catalytic biosensor can provide a solution for the POCT diagnosis of UTIs based on E. coli detection.

Fluorogenic RNA aptamer output sensors via transcription activated by recombinase polymerase amplification for nucleic acid testing

Sensitive, simple, and rapid nucleic acid testing used for pathogen detection are crucial for preventing outbreaks and transmission of infectious diseases. In this study, we present a fluorogenic RNA aptamer Output Sensors via transcription Activated by Recombinase polymerase amplification (RPA), termed ROSAR, for highly sensitive detection of DNA and RNA from pathogenic bacteria or viruses in clinical samples. The promoter primer and reporter primer facilitate the integration of the transcriptional promoter with the fluorogenic RNA aptamer transcription templates through the RPA of target DNA. Subsequently, the amplification products are transcribed by T7 RNA polymerase, producing RNA aptamer that binds to a fluorogenic dye. The assay, which can be completed within 50 min and can allow a limit of detection of level aM nucleic acid concentration, owning to the dual amplification effects of RPA and in vitro transcription. Furthermore, we develop a paper-based ROSAR by freeze-drying the reaction components, which is compatible with visual detection based on mobile phone fluorescent reader and suitable for point-of-care (POC) applications. The assay can detect various viral and bacterial nucleic acids, making it a highly promising tool for large-scale epidemic screening and rapid POC testing in home healthcare settings.

Evaluation of a rapid immunochromatographic test for the diagnosis of intestinal protozoan infections among patients attending a rural outreach outpatient department in Northern India.

Despite great efforts, intestinal protozoan infections remain a significant healthcare concern worldwide. Although many point-of-care (POC) tests are increasingly being used, microscopic examination of stool specimens remains the mainstay for their diagnosis, especially in resource-limited settings. We assessed the utility of rapid POC tests based on immunochromatography among patients from rural Northern India. A total of 78 patients were enrolled in the study. Out of nine specimens that tested positive for Giardia duodenalis on microscopy, an immunochromatographic test (ICT) could detect only five (55.55%). Entamoeba histolytica/dispar was demonstrated in two specimens on microscopy, both of which were missed by ICT. Its overall sensitivity, specificity, and positive and negative predictive value were 50%, 98.5%, 83.3%, and 93%, respectively. Its performance was considered unsatisfactory. Although ICT-based tests provide a relatively rapid and less labor-intensive alternative, they should be used to supplement and not replace stool microscopy.

Factors associated with mortality in HIV-TB co-infected patients during and after the course of TB treatment in high-burden settings, Mumbai, India: A cohort analysis.

Knowledge of factors associated with TB mortality during treatment and post treatment will help us develop better monitoring and implementation strategies for TB control. We designed the present study to examine the factors associated with mortality in HIV-TB co-infected patients during and after the course of TB treatment. This study is a cohort analysis of secondary data collected from 1804 HIV-TB co-infected individuals from 16 anti-retroviral therapy (ART) centres affiliated with the Mumbai Districts AIDS Control Society, Mumbai, India. We used Kaplan Meier survival curves and hazard ratios to estimate the mortality in patients. The overall mortality rate in this cohort was 1.14 per 100 per month. The mortality proportion was 18% (95% CI: 16.1%, 20.1%) during treatment and 10.6% (95% CI: 8.9%, 12.5%) in the post-treatment period. Mortality was significantly higher in those with a CD4 count 0-200 cells/mm3 (HR: 3.04, 95% CI: 2.13, 4.15; p < 0.001), and in patients who were ART naïve and referred to the ART centre with a diagnosis of TB (HR: 1.39, 95% CI: 1.06, 1.82; p = 0.016). Mortality was also significantly higher in the first 6 months after initiation of ART (HR: 1.36, 95% CI: 1.06, 1.75; p = 0.016). A decrease in the CD4 counts from initial levels at start of TB treatment to end of TB treatment was associated with higher mortality in the post-treatment period. The overall mortality remains high; early identification of TB and HIV disease, and use of rapid point of care tests for diagnosis of TB are needed across all health care facilities. Post-treatment follow-up and monitoring is important in HIV-TB co-infected patients, and post-treatment mortality should also be considered as one of the indicators for successful TB control programmes.

Evaluation of the accuracy of the Asanté assay as a point-of-care rapid test for HIV-1 recent infections using serum bank specimens from blood donors in South Africa, July 2018 - August 2021.

Point-of-care (POC) rapid recency testing can be used as a cost-effective tool to identify recently infected individuals (i.e. infected within the last 12 months) in near-real time, support epidemic control and identify hotspots for transmission as part of recent infection surveillance. To evaluate the performance of the Asanté (HIV-1) rapid recency assay as a POC rapid test among blood donors in South Africa (SA). The study was a cross-sectional and validity study of the Asanté HIV-1 Rapid Recency Assay performed on 715 consecutively archived plasma donor specimens from the SA National Blood Services to determine their recency and established HIV infection status. ELISA and rapid assays for HIV antibody detection were used as the reference-testing standard for confirming an infection, while the Maxim HIV-1 limiting antigen (LAg) avidity assay was used as a reference for comparing HIV recency status. Validity tests (sensitivity, specificity, negative and positive predictive values) and Cohen-Kappa tests of the agreement were conducted to compare the Asanté HIV-1 rapid recency assay results with the reference tests. Of the 715 studied blood samples, 63.1% (n=451/715) were confirmed to be HIV-positive based on the reference standard. The sensitivity and specificity of the Asanté HIV-1 rapid recency assay in diagnosing established HIV infection compared to the ELISA were 98.4% (95% CI 96.7 - 99.3) and 99.6% (95% CI 97.6 - 100), respectively. Compared with HIV rapid assay, the sensitivity and specificity of the Asanté HIV-1 rapid recency assay was 98.7% (95% CI 97.0 - 99.4) and 99.2% (95% CI 97.1 - 100), respectively. Of the 451 HIV-positive blood samples, 43% were confirmed as recent HIV infections by the Maxim HIV-1 LAg avidity assay. There was high agreement between the Asanté HIV-1 rapid recency assay and the Maxim HIV-1 LAg avidity assay (94.1%, k=0.879, p<0.0001). The sensitivity and specificity of the Asante HIV-1 assay was 89.4% (95% CI 84.0 - 93.0) and 97.7% (95% CI 94.8 - 99.0), respectively. The Asanté HIV-1 rapid recency assay test results demonstrated high accuracy (>90%) compared with the HIV ELISA and rapid assays for determining established infection and the Maxim HIV-1 LAg avidity assay for classifying recent HIV-1 infections. The assay's sensitivity for established infections was below the World Health Organization criteria (<99%) for POC devices. The Asanté HIV-1 rapid recency assay can be used to distinguish between recent and long-term infections, but may not be considered a POC test for determining HIV infection.

Performance of the Cue COVID-19 point-of-care molecular test: insights from a multi-site clinic service model.

The COVID-19 pandemic highlighted the critical need for rapid and accurate molecular diagnostic testing. The Cue COVID-19 Point-of-Care Test (Cue POCT) is a nucleic acid amplification test (NAAT), authorized by Health Canada and FDA as a POCT for SARS-CoV-2 detection. Cue POCT was deployed at a network of clinics in Ontario, Canada with n = 13,848 patrons tested between 17 July 2021 and 31 January 2022. The clinical performance and operational experience with Cue POCT were examined for this testing population composed mostly of asymptomatic individuals (93.7%). A head-to-head prospective clinical verification was performed between 17 July and 4 October for all POCT service clients (n = 3,037) with paired COVID-19 testing by Cue and RT-PCR. Prospective verification demonstrated a clinical sensitivity of 100% and clinical specificity of 99.4% for Cue COVID-19 POCT. The lack of false negatives and low false positive rate (0.64%), underscores the high accuracy (99.4%) of Cue POCT to provide rapid PCR quality results. Low error rates (cancellation rate of 0% and invalid rate of 0.63%) with the current software version were additionally noted. Taken together, these findings highlight the value of accurate molecular COVID-19 POCT in a distributed service delivery model to rapidly detect cases in the community with the potential to curb transmission in high-exposure settings (i.e., in-flight, congregate workplace, and social events). The insights gleaned from this operational implementation are readily transferable to future POCT diagnostic services. IMPORTANCE This manuscript reports on the findings of a large asymptomatic population who underwent surveillance COVID testing on the Cue COVID-19 Point-of-Care Test (POCT). Review of test performance of this rapid molecular POCT, as compared to gold standard RT-PCR, is valuable to many audiences, including public health, emergency testing services, employers, and the general population of consumers who are seeking a user-friendly, accurate, cost-effective, and sustainable testing model for COVID screening. The findings from this operational experience also inform future models of POCT services beyond COVID.

Recent Advances in Quantum Dot-Based Lateral Flow Immunoassays for the Rapid, Point-of-Care Diagnosis of COVID-19.

The COVID-19 pandemic has spurred demand for efficient and rapid diagnostic tools that can be deployed at point of care to quickly identify infected individuals. Existing detection methods are time consuming and they lack sensitivity. Point-of-care testing (POCT) has emerged as a promising alternative due to its user-friendliness, rapidity, and high specificity and sensitivity. Such tests can be conveniently conducted at the patient's bedside. Immunodiagnostic methods that offer the rapid identification of positive cases are urgently required. Quantum dots (QDs), known for their multimodal properties, have shown potential in terms of combating or inhibiting the COVID-19 virus. When coupled with specific antibodies, QDs enable the highly sensitive detection of viral antigens in patient samples. Conventional lateral flow immunoassays (LFAs) have been widely used for diagnostic testing due to their simplicity, low cost, and portability. However, they often lack the sensitivity required to accurately detect low viral loads. Quantum dot (QD)-based lateral flow immunoassays have emerged as a promising alternative, offering significant advancements in sensitivity and specificity. Moreover, the lateral flow immunoassay (LFIA) method, which fulfils POCT standards, has gained popularity in diagnosing COVID-19. This review focuses on recent advancements in QD-based LFIA for rapid POCT COVID-19 diagnosis. Strategies to enhance sensitivity using QDs are explored, and the underlying principles of LFIA are elucidated. The benefits of using the QD-based LFIA as a POCT method are highlighted, and its published performance in COVID-19 diagnostics is examined. Overall, the integration of quantum dots with LFIA holds immense promise in terms of revolutionizing COVID-19 detection, treatment, and prevention, offering a convenient and effective approach to combat the pandemic.

The QuantuMDx Q-POC SARS-CoV-2 RT-PCR assay for rapid detection of COVID-19 at point-of-care: preliminary evaluation of a novel technology

Accurate and rapid point-of-care (PoC) diagnostics are critical to the control of the COVID-19 pandemic. The current standard for accurate diagnosis of SARS-CoV-2 is laboratory-based reverse transcription polymerase chain reaction (RT-PCR) assays. Here, a preliminary prospective performance evaluation of the QuantuMDx Q-POC SARS-CoV-2 RT-PCR assay is reported. Between November 2020 and March 2021, 49 longitudinal combined nose/throat (NT) swabs from 29 individuals hospitalised with RT-PCR confirmed COVID-19 were obtained at St George’s Hospital, London. In addition, 101 mid-nasal (MN) swabs were obtained from healthy volunteers in June 2021. These samples were used to evaluate the Q-POC SARS-CoV-2 RT-PCR assay. The primary analysis was to compare the sensitivity and specificity of the Q-POC test against a reference laboratory-based RT-PCR assay. The overall sensitivity of the Q-POC test compared with the reference test was 96.88% (83.78– 99.92% CI) for a cycle threshold (Ct) cut-off value for the reference test of 35 and 80.00% (64.35–90.95% CI) without altering the reference test’s Ct cut-off value of 40. The Q-POC test is a sensitive, specific and rapid PoC test for SARS-CoV-2 at a reference Ct cut-off value of 35. The Q-POC test provides an accurate option for RT-PCR at PoC without the need for sample pre-processing and laboratory handling, enabling rapid diagnosis and clinical triage in acute care and other settings.