Project description:IntroductionManagement of the COVID-19 pandemic is hampered by long delays associated with centralised laboratory PCR testing. In hospitals this leads to poor patient flow and nosocomial transmission and so rapid, accurate diagnostic tests are urgently required. The FebriDx is a point-of-care test that detects an antiviral host response protein in finger prick blood within 10 min, but its accuracy for the identification of COVID-19 is unknown.MethodsWe performed a real-world diagnostic accuracy study of FebriDx in hospitalised patients during the first wave of the pandemic. Measures of diagnostic accuracy were calculated based on FebriDx results compared to the reference standard of SARS-CoV-2 PCR on combined nose and throat swabs. A multivariable predictive model including FebriDx, age, sex, and clinical characteristics was developed and underwent internal validation.ResultsFebriDx was performed on 251 patients and gave a valid result in 248. 118 of 248 (48%) were PCR positive for COVID-19. FebriDx results were available after 10 min compared with 1.7 (1.6 to 2.1) hours with point-of-care PCR testing and 23.4 (17.2 to 31.1) hours with laboratory PCR testing. Sensitivity of FebriDx for the identification of COVID-19 was 93% (110/118; 95% CI 87 to 97%) and specificity was 86% (112/130; 95%CI 79 to 92%). Positive and negative likelihood ratios were 6.73 (95%CI 4.37 to 10.37) and 0.08 (95%CI 0.04 to 0.15) respectively. In the multivariate model age, sex and other clinical features did not contribute significantly to the effect of the FebriDx result in distinguishing patients with and without COVID-19.ConclusionsDuring the first wave of the pandemic, FebriDx had high accuracy for the identification of COVID-19 in hospitalised adults and could be deployed as a front door triage tool.Trial registrationISRCTN14966673.
Project description:Rapid and accurate point-of-care (POC) tuberculosis (TB) diagnostics are crucial to bridge the TB diagnostic gap. Leveraging recent advancements in COVID-19 diagnostics, we explored adapting commercially available POC SARS-CoV-2 tests for TB diagnosis in line with the World Health Organization (WHO) target product profiles (TPPs). A scoping review was conducted following PRISMA-ScR guidelines to systematically map POC antigen and molecular SARS-CoV-2 diagnostic tests potentially meeting the TPPs for TB diagnostic tests for peripheral settings. Data were gathered from PubMed/MEDLINE, bioRxiv, medRxiv, publicly accessible in vitro diagnostic test databases, and developer websites up to 23 November 2022. Data on developer attributes, operational characteristics, pricing, clinical performance, and regulatory status were charted using standardized data extraction forms and evaluated with a standardized scorecard. A narrative synthesis of the data is presented. Our search yielded 2003 reports, with 408 meeting eligibility criteria. Among these, we identified 66 commercialized devices: 22 near-POC antigen tests, 1 POC molecular test, 31 near-POC molecular tests, and 12 low-complexity molecular tests potentially adaptable for TB. The highest-scoring SARS-CoV-2 diagnostic tests were the near-POC antigen platform LumiraDx (Roche, Basel, Switzerland), the POC molecular test Lucira Check-It (Pfizer, New York, NY, USA), the near-POC molecular test Visby (Visby, San Jose, CA, USA), and the low-complexity molecular platform Idylla (Biocartis, Lausanne, Switzerland). We highlight a diverse landscape of commercially available diagnostic tests suitable for potential adaptation to peripheral TB testing. This work aims to bolster global TB initiatives by fostering stakeholder collaboration, leveraging SARS-CoV-2 diagnostic technologies for TB, and uncovering new commercial avenues to tackle longstanding challenges in TB diagnosis.
Project description:We evaluated the Panbio™ COVID-19 Ag Rapid Test Device as a point-of-care diagnostic tool for COVID-19 in 357 patients at a pediatric emergency department. Thirty-four patients tested positive by reverse transcription polymerase chain reaction, of which 24 were positive by the antigen assay. The sensitivity and specificity of the assay were 70.5% and 100%, respectively.
Project description:A molecular diagnostic method for robust detection of Ebola virus (EBOV) at the point of care (POC) directly from blood samples is described. This assay is based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) of the glycoprotein gene of EBOV. Complete reaction formulations were lyophilized in 0.2-mL polymerase chain reaction tubes. RT-LAMP reactions were performed on a battery-operated isothermal instrument. Limit of detection of this RT-LAMP assay was 2.8 × 102 plaque-forming units (PFU)/test and 1 × 103 PFU/test within 40 minutes for EBOV-Kikwit and EBOV-Makona, respectively. This assay was found to be specific for the detection of EBOV, as no nonspecific amplification was detected in blood samples spiked with closely related viruses and other pathogens. These results showed that this diagnostic test can be used at the point of care for rapid and specific detection of EBOV directly from blood with high sensitivity within 40 minutes.
Project description:IntroductionIn 2014, the WHO published high-priority target product profiles (TPPs) for new tuberculosis (TB) diagnostics to align end-user needs with test targets and specifications; nevertheless, no TB test meets these targets to date. The COVID-19-driven momentum in the diagnostics world offers an opportunity to address the long-standing lack of innovation in the field of TB diagnostics. This scoping review aims to summarise point-of-care (POC) molecular and antigen tests for COVID-19 diagnosis that, when applied to TB, potentially meet WHO TPPs. This summary of currently available innovative diagnostic tools will guide the development of novel TB diagnostics toward the WHO-set targets.Methods and analysisWe will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension Scoping Reviews recommendations. MEDLINE (via PubMed), bioRxiv, MedRxiv and other publicly available in vitro diagnostic test databases were searched on 23 November 2022. POC antigen or molecular tests developed for SARS-CoV-2 detection that meet the eligibility criteria will be included in the review. Developer description, test description, operation characteristics, pricing information, performance and commercialisation status of diagnostic tests identified will be extracted using a predefined standardised data extraction form. Two reviewers will independently perform the screening and data extraction. A narrative synthesis of the final data will be provided.Ethics and disseminationNo ethical approval is required because individual patient data will not be included. The findings will be published in open-access scientific journals.
Project description:Diagnostics of SARS-CoV-2 infection using real-time reverse-transcription polymerase chain reaction (RT-PCR) on nasopharyngeal swabs is now well-established, with saliva-based testing being lately more widely implemented for being more adapted for self-testing approaches. In this study, we introduce a different concept based on exhaled breath condensate (EBC), readily collected by a mask-based sampling device, and detection with an electrochemical biosensor with a modular architecture that enables fast and specific detection and quantification of COVID-19. The face mask forms an exhaled breath vapor containment volume to hold the exhaled breath vapor in proximity to the EBC collector to enable a condensate-forming surface, cooled by a thermal mass, to coalesce the exhaled breath into a 200-500 μL fluid sample in 2 min. EBC RT-PCR for SARS-CoV-2 genes (E, ORF1ab) on samples collected from 7 SARS-CoV-2 positive and 7 SARS-CoV-2 negative patients were performed. The presence of SARS-CoV-2 could be detected in 5 out of 7 SARS-CoV-2 positive patients. Furthermore, the EBC samples were screened on an electrochemical aptamer biosensor, which detects SARS-CoV-2 viral particles down to 10 pfu mL-1 in cultured SARS-CoV-2 suspensions. Using a "turn off" assay via ferrocenemethanol redox mediator, results about the infectivity state of the patient are obtained in 10 min.
Project description:Rapid on-site diagnosis of emerging pathogens is key for early identification of infected individuals and for prevention of further spreading in a population. Currently available molecular diagnostic tests are instrument-based whereas rapid antibody and antigen tests are often not sufficiently sensitive for detection in pre-symptomatic subjects. There is a need for rapid point of care molecular screening tests that can be easily adapted to emerging pathogens and are selective, sensitive, reliable in different settings around the world. We have developed a simple, rapid (<30 min), and inexpensive test for SARS-CoV-2 that is based on combination of isothermal reverse transcription recombinase polymerase amplification (RT-RPA) using modified primers and visual detection with paper-based microfluidics. Our test (CoRapID) is specific for SARS-CoV-2 (alpha to omicron variants) and does not detect other coronaviruses and pathogens by in silico and in vitro analysis. A two-step test protocol was developed with stable lyophilized reagents that reduces handling by using portable and disposable components (droppers, microapplicators/swabs, paper-strips). After optimization of assay components and conditions, we have achieved a limit of detection (LoD) of 1 copy/reaction by adding a blocking primer to the lateral flow assay. Using a set of 138 clinical samples, a sensitivity of 88.1% (P < 0.05, CI: 78.2-93.8%) and specificity of 93.9% (P < 0.05, CI: 85.4-97.6%) was determined. The lack of need for instrumentation for our CoRapID makes it an ideal on-site primary screening tool for local hospitals, doctors' offices, senior homes, workplaces, and in remote settings around the world that often do not have access to clinical laboratories.
Project description:High throughput sequencing is performed on mRNA isolated from whole blood of adult Covid-19 patients, bacterial coinfection with Covid-19 and healthy controls in a South Indian cohort. Samples were collected from individuals at the time of hospitalization or visit to clinic. The Covid-19 samples are categorized by severeity.
Project description:Abstract The HAT-field protocol described here is an optimization of the recently published HAT hemagglutination test, for the detection of antibodies directed against the receptor binding domain (RBD) of the SARS-Cov-2 virus (Townsend et al. 2021). HAT and HAT-field are both based on hemagglutination triggered by a single reagent, the IH4-RBD recombinant protein. A sample of IH4-RBD sufficient for several thousand tests or a plasmid encoding IH4-RBD can be obtained from the authors of our first paper (Townsend et al. 2021). Using titration of IH4-RBD, HAT-field now allows a quantitative assessment of antibody levels in a single step, using a few microliters of whole blood, such as can be obtained by finger prick, and requires only very simple disposable equipment. Because it is based on a single soluble reagent, the test can be adapted very simply and rapidly to detect antibodies against variants of the SARS-CoV-2, or conceivably against different pathogens. HAT-field appears well suited to provide quantitative assessments of the serological protection of populations as well as individuals, and given its very low cost, the stability of the IH4-RBD reagent in the adapted buffer, and the simplicity of the procedure, could be deployed pretty much anywhere, including in the poorest countries and the most remote corners of the globe.