scholarly journals Two-Stage Isothermal Enzymatic Amplification for Concurrent Multiplex Molecular Detection

2017 ◽  
Vol 63 (3) ◽  
pp. 714-722 ◽  
Author(s):  
Jinzhao Song ◽  
Changchun Liu ◽  
Michael G Mauk ◽  
Shelley C Rankin ◽  
James B Lok ◽  
...  
Keyword(s):  
Point Of Care ◽  
Healthcare Providers ◽  
High Sensitivity ◽  
Ease Of Use ◽  
Isothermal Amplification ◽  
Healthcare Personnel ◽  
Highly Sensitive ◽  
Simple Implementation ◽  
Rapid Amplification ◽  
High Level

Abstract BACKGROUND The wide array of pathogens responsible for infectious diseases makes it difficult to identify causative pathogens with single-plex tests. Although multiplex PCR detects multiple targets, it is restricted to centralized laboratories, which delays test results or makes multiplexing unavailable, depriving healthcare providers of critical, real-time information. METHODS To address the need for point-of-care (POC) highly multiplexed tests, we propose the 2-stage, nested-like, rapid (<40 min) isothermal amplification assay, dubbed rapid amplification (RAMP). RAMP's first-stage uses outer loop-mediated isothermal amplification (LAMP) primers to amplify all targets with recombinase polymerase amplification (RPA). First-stage amplicons are aliquoted to second stage reactors, each specialized for a specific target, to undergo LAMP. The assay is implemented in a microfluidic chip. LAMP amplicons are detected in situ with colorimetric dye or with a fluorescent dye and a smartphone. RESULTS In experiments on a benchtop and in a microfluidic format, RAMP demonstrated high level of multiplexing (≥16); high sensitivity (i.e., 1 plaque-forming unit of Zika virus) and specificity (no false positives or negatives); speed (<40 min); ease of use; and ability to cope with minimally processed samples. CONCLUSIONS RAMP is a hybrid, 2-stage, rapid, and highly sensitive and specific assay with extensive multiplexing capabilities, combining the advantages of RPA and LAMP, while circumventing their respective shortcomings. RAMP can be used in the lab, but one of its distinct advantages is amenability to simple implementation in a microfluidic format for use at the POC, providing healthcare personnel with an inexpensive, highly sensitive tool to detect multiple pathogens in a single sample, on site.

scholarly journals Direct-RT-qPCR Detection of SARS-CoV-2 without RNA Extraction as Part of a COVID-19 Testing Strategy: From Sample to Result in One Hour

Diagnostics ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 605 ◽  
Author(s):  
Eva Kriegova ◽  
Regina Fillerova ◽  
Petr Kvapil
Keyword(s):  
High Throughput Screening ◽  
High Speed ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rna Extraction ◽  
Rna Isolation ◽  
High Sensitivity ◽  
Ease Of Use ◽  
Diagnostic Tools ◽  
Heat Inactivation

Due to the lack of protective immunity in the general population and the absence of effective antivirals and vaccines, the Coronavirus disease 2019 (COVID-19) pandemic continues in some countries, with local epicentres emerging in others. Due to the great demand for effective COVID-19 testing programmes to control the spread of the disease, we have suggested such a testing programme that includes a rapid RT-qPCR approach without RNA extraction. The Direct-One-Step-RT-qPCR (DIOS-RT-qPCR) assay detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in less than one hour while maintaining the high sensitivity and specificity required of diagnostic tools. This optimised protocol allows for the direct use of swab transfer media (14 μL) without the need for RNA extraction, achieving comparable sensitivity to the standard method that requires the time-consuming and costly step of RNA isolation. The limit of detection for DIOS-RT-qPCR was lower than seven copies/reaction, which translates to 550 virus copies/mL of swab. The speed, ease of use and low price of this assay make it suitable for high-throughput screening programmes. The use of fast enzymes allows RT-qPCR to be performed under standard laboratory conditions within one hour, making it a potential point-of-care solution on high-speed cycling instruments. This protocol also implements the heat inactivation of SARS-CoV-2 (75 °C for 10 min), which renders samples non-infectious, enabling testing in BSL-2 facilities. Moreover, we discuss the critical steps involved in developing tests for the rapid detection of COVID-19. Implementing rapid, easy, cost-effective methods can help control the worldwide spread of the COVID-19 infection.

Usability Evaluation of User Requirement–Based Teleconsultation Robots: A Preliminary Report from South Korea

2020 ◽  
Vol 59 (02/03) ◽  
pp. 086-095
Author(s):  
Hyeongsuk Lee ◽  
Jeongeun Kim ◽  
Sukwha Kim ◽  
Hyoun-Joong Kong ◽  
Hyunjin Joo ◽  
...  
Keyword(s):  
Health Care ◽  
User Interface ◽  
Point Of Care ◽  
Healthcare Providers ◽  
Usability Evaluation ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Perceived Ease Of Use ◽  
User Requirement ◽  
Effective Decision Making

Abstract Background Telepresence robots used to deliver a point-of-care (POC) consultation system that may provide value to enable effective decision making by healthcare providers at care sites. Objectives This study aimed to evaluate usability of teleconsultation robots, based on endusers' needs, that can improve acceptance in future robot applications. Methods This is a single group postdesign study using mixed methods to assess the usability of teleconsultation robots using scenarios. To collect opinions from various departments, 15 nurses or physicians currently working at medical institutions in Korea were selected using purposive sampling. The usability evaluation was conducted on healthcare providers twice at the simulation center; the think-aloud method was used and surveys and interviews were conducted to identify problems or improvements that may arise from the use of robots in hospital settings. Results The results showed that perceived usefulness, perceived ease of use, and satisfaction level each scored 4 points or higher out of 7 points, showing usability of midhigh level. Camera angle control and robot driving functions were the most difficult. Other basic robot user interface was shown to be relatively easy. There was no difference in usability depending on the characteristics of the evaluator. Some functions including user interface were modified based on the usability test. Conclusion Using robots in health care institutions may support effective communication among healthcare providers, thus contributing to health care improvement.

scholarly journals Specific and sensitive, ready-to-use universal fungi detection by visual color using ITS1 loop-mediated isothermal amplification combined hydroxynaphthol blue

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11082
Author(s):  
Ilada Choopara ◽  
Yothin Teethaisong ◽  
Narong Arunrut ◽  
Sudaluck Thunyaharn ◽  
Wansika Kiatpathomchai ◽  
...  
Keyword(s):  
Point Of Care ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Fungal Species ◽  
Isothermal Amplification ◽  
Loop Mediated Isothermal Amplification ◽  
Fungal Isolates ◽  
Simple Detection ◽  
Hydroxynaphthol Blue ◽  
Life Threatening

Being ubiquitous, fungi are common opportunistic pathogens to humans that can lead to invasive and life-threatening infections in immunocompromised individuals. Eukaryote-resembling cell membrane and filamentous branches make the fungal diagnosis difficult. This study therefore developed a ready-to-use ITS1 loop-mediated isothermal amplification combined with hydroxynaphthol blue (LAMP-HNB) for rapid, sensitive and specific colorimetric detection of universal fungi in all phyla. The ITS1 LAMP-HNB could identify every evolutionary phylum of fungi according to sequence analyses. We tested a total of 30 clinically relevant fungal isolates (representing three major human pathogenic phyla of fungi, namely Zygomycota, Ascomycota and Basidiomycota) and 21 non-fungal isolates, and the ITS1 LAMP-HNB properly identified all isolates, with a detection limit of as low as 4.6 ag (9.6 copies), which was identical to ITS1 and 18S rDNA PCR. The assays were also validated on the feasibility of point-of-care diagnostic with real food (dry peanuts, chili and garlics) and blood samples. Furthermore, the shelf life of our ready-to-use ITS1 LAMP activity (≥50%) was more than 40 days at 30 °C with 3–5% polyvinyl alcohol or glycerol additive. The results supported the ready-to-use ITS1 LAMP-HNB for simple detection of fungi contamination with high sensitivity in local and resource-constrained areas to prevent opportunistic fungal species infections.

scholarly journals Isothermal Amplification of Nucleic Acids Coupled with Nanotechnology and Microfluidic Platforms for Detecting Antimicrobial Drug Resistance and Beyond

2021 ◽  
Author(s):  
Seyedeh Zahra Alamolhoda ◽  
Nosratollah Zarghami ◽  
Houman Kahroba ◽  
Ahmad Mehdipour ◽  
Mohammad Pourhassan-Moghaddam ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Point Of Care ◽  
High Sensitivity ◽  
Molecular Techniques ◽  
Isothermal Amplification ◽  
High Tech ◽  
Antimicrobial Drug Resistance ◽  
Resource Limited ◽  
Accessible Point ◽  
Sensitivity Specificity

Antibiotic resistance is one of the serious health-threatening issues globally, the control of which is indispensable for rapid diagnosis and treatment because of the high prevalence and risks of pathogenicity. Traditional and molecular techniques are relatively expensive, complex, and non-portable, requiring facilities, trained personnel, and high-tech laboratories. Widespread and timely-detection is vital to the better crisis management of rapidly spreading infective diseases, especially in low-tech regions and resource-limited settings. Hence, the need for inexpensive, fast, simple, mobile, and accessible point-of-care (POC) diagnostics is highly demanding. Among different biosensing methods, the isothermal amplification of nucleic acids is favorite due to their simplicity, high sensitivity/specificity, rapidity, and portability, all because they require a constant temperature to work. Isothermal amplification methods are utilized for detecting various targets, including DNA, RNA, cells, proteins, small molecules, ions, and viruses. In this paper, we discuss various platforms, applications, and potentials of isothermal amplification techniques for biosensing of antimicrobial resistance. We also evaluate the potential of these methods, coupled with the novel and rapidly-evolving platforms offered by nanotechnology and microfluidic devices.

Endocavity Ultrasound Transducers: Why High-Level Disinfection Is Necessary

2020 ◽  
Author(s):  
Susan Campbell Westerway ◽  
Jocelyne M. Basseal
Keyword(s):  
Imaging Modality ◽  
Case Reports ◽  
Healthcare Providers ◽  
Pathogen Transmission ◽  
Ease Of Use ◽  
Transmission Risk ◽  
Ultrasound Transducers ◽  
Perceived Safety ◽  
Infection Transmission ◽  
High Level

AbstractAs a medical imaging modality, ultrasound is used by a wide cross-section of practitioners including radiologists, obstetricians, gynecologists, gastroenterologists, urologists and cardiologists. The increasing popularity of ultrasound as a diagnostic tool is due not only to the ease of use and portability of systems, but also to the perceived safety aspect of the examination. This latter point needs to be examined. As with any reusable medical device, the ultrasound transducer, also known as a probe, could potentially be a vector for the transmission of pathogenic viruses and fungi between patients if not correctly disinfected after each use. This transmission risk is magnified for an endocavity transducer that has come in contact with the vagina, anal canal or oral cavity, as it could be contaminated with organisms transmitted by blood or mucosal, genital or rectal secretions. Based on the Spaulding system, transducers that come in contact with mucous membranes are classified as semi-critical devices that require high-level disinfection (HLD) after each patient procedure. This HLD process should eliminate all microorganisms except high numbers of bacterial endospores. Only a small number of countries worldwide have implemented transducer reprocessing guidelines that adhere to the Spaulding classification and recommend HLD for endocavity transducers. Overall, there is a lack of conformity among global health agencies regarding the use of HLD for endocavity transducers. This is primarily due to the perception that the infection transmission risk is negligible and that if an endocavity transducer has been covered with a single-use sheath for the procedure, then low-level disinfection provides sufficient protection against pathogen transmission. The objective of this study was to review the published risk of infection transmission from endocavity transducers. By highlighting the outbreaks and case reports that implicate pathogen transmission from transducers, we posit that HLD should be a global standard of practice for the reprocessing of endocavity transducers. It requires substantial time for national health administrations to develop and legislate new recommendations, and for practice changes to be accepted and implemented by healthcare providers. We recommend that Joint Commission International (JCI) and other equivalent organizations enforce the use of HLD of endocavity ultrasound transducers during their accreditation reviews.

scholarly journals Diagnostic accuracy of a novel SARS-CoV-2 antigen-detecting rapid diagnostic test from standardized self-collected anterior nasal swabs

2021 ◽  
Author(s):  
Bilgin Osmanodja ◽  
Klemens Budde ◽  
Daniel Zickler ◽  
Marcel G. Naik ◽  
Jörg Hofmann ◽  
...  
Keyword(s):  
Primary Endpoint ◽  
Point Of Care ◽  
High Viral Load ◽  
Ease Of Use ◽  
Healthcare Personnel ◽  
Sample Collection ◽  
Rt Pcr ◽  
Self Testing ◽  
Nasal Swabs ◽  
Potential Benefits

AbstractBackgroundAntigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 offer new opportunities for the quick and laboratory-independent identification of infected individuals for control of the SARS-CoV-2 pandemic. Despite the potential benefits, nasopharyngeal sample collection is frequently perceived as uncomfortable by patients and requires trained healthcare personnel with protective equipment. Therefore, anterior nasal self-sampling is increasingly recognized as a valuable alternative.MethodsWe performed a prospective, single-center, point of care validation of an Ag-RDT using a polypropylene absorbent collector for standardized self-collected anterior nasal swabs. Real-Time Polymerase Chain Reaction (RT-PCR) from combined oropharyngeal/nasopharyngeal swabs served as a comparator. Primary endpoint was sensitivity of the standardized Ag-RDT in symptomatic patients with medium or high viral concentration (≥ 1 million RNA copies on RT-PCR for SARS-CoV-2).ResultsBetween February 12 and March 22, 2021, 388 participants were enrolled. After exclusion of 9 patients for which no PCR result could be obtained, the novel Ag-RDT was evaluated based on 379 participants, of which 273 were symptomatic and 106 asymptomatic. In 61 samples from symptomatic patients with medium or high viral load (≥ 1 million RNA copies), the sensitivity of the standardized Ag-RDT was 96.7% (59/61; 95%CI: 88.7-99.6%) for the primary endpoint. In total, 62 positive Ag-RDT results were detected out of 70 RT-PCR positive individuals, yielding an overall sensitivity of 88.6% (95%CI: 78.7-94.9%). Specificity was 99.7% (95%CI: 98.2-100%) in 309 RT-PCR negative individuals.ConclusionHere, we present a validation of a novel Ag-RDT with a standardized sampling process for anterior nasal self-collection, which meets WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, this assay could be beneficial due to its rapid results, ease of use, and suitability for standardized self-testing.(Funded by Drägerwerk AG & Co. KGaA, Lübeck, Germany; ClinicalTrials.gov number NCT04698993)

scholarly journals Multiplexed, quantitative serological profiling of COVID-19 from blood by a point-of-care test

2021 ◽  
Vol 7 (26) ◽  
pp. eabg4901
Author(s):  
Jacob T. Heggestad ◽  
David S. Kinnamon ◽  
Lyra B. Olson ◽  
Jason Liu ◽  
Garrett Kelly ◽  
...  
Keyword(s):  
Prognostic Biomarker ◽  
Point Of Care ◽  
High Sensitivity ◽  
Interferon Γ ◽  
Live Virus ◽  
Point Of Care Test ◽  
Highly Sensitive ◽  
Good Concordance ◽  
Longitudinal Sampling ◽  
User Intervention

Highly sensitive, specific, and point-of-care (POC) serological assays are an essential tool to manage coronavirus disease 2019 (COVID-19). Here, we report on a microfluidic POC test that can profile the antibody response against multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens—spike S1 (S1), nucleocapsid (N), and the receptor binding domain (RBD)—simultaneously from 60 μl of blood, plasma, or serum. We assessed the levels of antibodies in plasma samples from 31 individuals (with longitudinal sampling) with severe COVID-19, 41 healthy individuals, and 18 individuals with seasonal coronavirus infections. This POC assay achieved high sensitivity and specificity, tracked seroconversion, and showed good concordance with a live virus microneutralization assay. We can also detect a prognostic biomarker of severity, IP-10 (interferon-γ–induced protein 10), on the same chip. Because our test requires minimal user intervention and is read by a handheld detector, it can be globally deployed to combat COVID-19.

scholarly journals Head-to-head comparison of SARS-CoV-2 antigen-detecting rapid test with self-collected anterior nasal swab versus professional-collected nasopharyngeal swab

2020 ◽  
Author(s):  
Andreas K. Lindner ◽  
Olga Nikolai ◽  
Franka Kausch ◽  
Mia Wintel ◽  
Franziska Hommes ◽  
...  
Keyword(s):  
Point Of Care ◽  
Rapid Test ◽  
High Viral Load ◽  
Ease Of Use ◽  
Healthcare Personnel ◽  
Nasopharyngeal Swab ◽  
Swab Sample ◽  
Rt Pcr ◽  
Percent Agreement ◽  
Accuracy Study

AbstractBackgroundTwo antigen-detecting rapid diagnostic tests (Ag-RDTs) are now approved through the WHO Emergency Use Listing procedure and can be performed at the point-of-care. However, both tests use nasopharyngeal (NP) swab samples. NP swab samples must be collected by trained healthcare personnel with protective equipment and are frequently perceived as uncomfortable by patients.MethodsThis was a manufacturer-independent, prospective diagnostic accuracy study with comparison of a supervised, self-collected anterior nose (AN) swab sample with a professional-collected NP swab sample, using a WHO-listed SARS-CoV-2 Ag-RDT, STANDARD Q COVID-19 Ag Test (SD Biosensor), which is also being distributed by Roche. The reference standard was RT-PCR from an oro-/nasopharyngeal swab sample. Percent positive and negative agreement as well as sensitivity and specificity were calculated.ResultsAmong the 289 participants, 39 (13.5%) tested positive for SARS-CoV-2 by RT-PCR. The positive percent agreement of the two different sampling techniques for the Ag-RDT was 90.6% (CI 75.8-96.8). The negative percent agreement was 99.2% (CI 97.2-99.8). The Ag-RDT with AN sampling showed a sensitivity of 74.4% (29/39 PCR positives detected; CI 58.9-85.4) and specificity of 99.2% (CI 97.1-99.8) compared to RT-PCR. The sensitivity with NP sampling was 79.5% (31/39 PCR positives detected; CI 64.5-89.2) and specificity was 99.6% (CI 97.8-100). In patients with high viral load (>7.0 log 10 RNA SARS-CoV2/swab), the sensitivity of the Ag-RDT with AN sampling was 96% and 100% with NP sampling.ConclusionSupervised self-sampling from the anterior nose is a reliable alternative to professional nasopharyngeal sampling using a WHO-listed SARS-CoV-2 Ag-RDT. Considering the ease-of-use of Ag-RDTs, self-sampling and potentially patient self-testing at home may be a future use case.

Abstract P465: Standardizing Hypertension Management In A Primary Care Setting In India Through A Protocol Based Model

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Priyanka Satish ◽  
Aditya Khetan ◽  
Shyamsundar Raithatha ◽  
Richard A Josephson
Keyword(s):  
Point Of Care ◽  
Healthcare Providers ◽  
Ease Of Use ◽  
Hypertension Management ◽  
Health And Wellness ◽  
Middle Income ◽  
Middle Income Countries ◽  
Healthcare Settings ◽  
Urine Albumin

Hypertension is a leading cause of death in India. There are numerous barriers to adequate management of hypertension in Indian healthcare settings, including therapeutic inertia and the lack of a systematic approach. Standardizing hypertension management through an evidence based model that sets thresholds for diagnosis, treatment goals, follow up intervals and choice of drugs can lead to improved management of hypertension in an individual hospital or health system. We describe the design of a model that focuses on efficacy, safety and ease of use by healthcare providers with different levels of training. The algorithm endorses a urine albumin first approach in deciding the course of antihypertensive therapy. Providers undergo training in the implementation of this model using a training guide and handout developed for this purpose. The algorithm itself can be utilized as a point of care reference by individual practitioners, hospitals, primary health centers (PHCs) and the Health and Wellness Centers (HWCs) under the Ayushman Bharat initiative. We plan to evaluate the effectiveness of our model at Shree Krishna Hospital, Gujarat, India through a quality improvement framework. The algorithm is designed to allow adaptability to individual institutional requirements in India (and similar low and middle income countries) while standardizing the basic elements of hypertension management.

One-step detection of microRNA with high sensitivity and specificity via target-triggered loop-mediated isothermal amplification (TT-LAMP)

2017 ◽  
Vol 53 (80) ◽  
pp. 11040-11043 ◽  
Author(s):  
Yuanyuan Sun ◽  
Hui Tian ◽  
Chenghui Liu ◽  
Yueying Sun ◽  
Zhengping Li
Keyword(s):  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Isothermal Amplification ◽  
Sensitive Detection ◽  
Step Detection ◽  
Loop Mediated Isothermal Amplification ◽  
Highly Sensitive ◽  
One Step ◽  
Highly Sensitive Detection

A target-triggered loop-mediated isothermal amplification (TT-LAMP) mechanism is developed for simple one-step but highly sensitive detection of microRNAs.

Sign in / Sign up

Export Citation Format

Share Document