A Novel Approach for Routinely Assessing Laboratory Sigma Metrics for a Broad Range of Automated Assays

BACKGROUND

Sigma metrics have been adapted for the clinical laboratory to incorporate observed accuracy, precision, and total error allowed. The higher the Sigma level for a process, the better performance that process has. A limitation of studies assessing Sigma metrics is that they are performed on a small number of well-controlled systems.

METHODS

An algorithm was developed to extract QC data and derive the Sigma metric for 115 analytes from sites connected to the QuidelOrtho E-Connectivity® database. The median of these results was then used to derive the Sigma metric for each assay.

RESULTS

In this analysis, 79 out of 115 (68.7%) of the assays assessed achieved 6 Sigma or better and 98 out of 115 (85.2%) achieved 5 Sigma or better.

CONCLUSIONS

This study has demonstrated a methodology that can be used to condense Sigma metrics from hundreds of analyzers into a single metric of assay quality. Because these analyzers are running in working laboratories from around the world, this analysis can serve as a baseline for understanding the assay performance achieved in the presence of variabilities such as lab-to-lab, instrument-to-instrument, material handling, environmental conditions, and reagent lot. The significant number of assays demonstrating high Sigma levels did so despite this variation. The ability of the methods reported here to include hundreds of analyzers represents a novel approach for assessing Sigma metrics in clinical laboratories.

CXCL13 in laboratory diagnosis of Lyme neuroborreliosis-the performance of the recomBead and ReaScan CXCL13 assays in human cerebrospinal fluid samples

The chemokine CXCL13 is used as complement to serology in the diagnostics of Lyme neuroborreliosis (LNB). We evaluated and compared the semi-quantitative, cassette-based ReaScan CXCL13 assay with the quantitative recomBead CXCL13 assay using a collection of 209 cerebrospinal fluid samples. The categorical agreement between results interpreted as negative, grey zone, and positive by the two methods was 87%. The diagnostic sensitivity was higher using the recomBead assay, whereas specificity was higher using ReaScan. Few manual steps, and a short turn-around time with no batching of samples makes the ReaScan CXCL13 assay an attractive complement to serology in the diagnostics of LNB.

Laboratory and Field Evaluation of the Crystal VC-O1 Cholera Rapid Diagnostic Test

Cholera is a severe acute, highly transmissible diarrheal disease which affects many low- and middle-income countries. Outbreaks of cholera are confirmed using microbiological culture, and additional cases during the outbreak are generally identified based on clinical case definitions, rather than laboratory confirmation. Many low-resource areas where cholera occurs lack the capacity to perform culture in an expeditious manner. A simple, reliable, and low-cost rapid diagnostic test (RDT) would improve identification of cases allowing rapid response to outbreaks. Several commercial RDTs are available for cholera testing with two lines to detect either serotypes O1 and O139; however, issues with sensitivity and specificity have not been optimal with these bivalent tests. Here, we report an evaluation of a new commercially available cholera dipstick test which detects only serotype O1. In both laboratory and field studies in Kenya, we demonstrate high sensitivity (97.5%), specificity (100%), and positive predictive value (100%) of this new RDT targeting only serogroup O1. This is the first field evaluation for the new Crystal VC-O1 RDT; however, with these high-performance metrics, this RDT could significantly improve cholera outbreak detection and improve surveillance for better understanding of cholera disease burden.

Facile biosensors for rapid detection of COVID-19

Currently the world is being challenged by a public health emergency caused by the coronavirus pandemic (COVID-19). Extensive efforts in testing for coronavirus infection, combined with isolating infected cases and quarantining those in contact, have proven successful in bringing the epidemic under control. Rapid and facile screening of this disease is in high demand. This review summarises recent advances in strategies reported by international researchers and engineers concerning how to tackle COVID-19 via rapid testing, mainly through nucleic acid- and antibody- testing. The roles of biosensors as powerful analytical tools are emphasized for the detection of viral RNAs, surface antigens, whole viral particles, antibodies and other potential biomarkers in human specimen. We critically review in depth newly developed biosensing methods especially for in-field and point-of-care detection of SARS-CoV-2. Additionally, this review describes possible future strategies for virus rapid detection. It helps researchers working on novel sensor technologies to tailor their technologies in a way to address the challenge for effective detection of COVID-19.

Laboratory Maintenance and Propagation of Freshwater Planarians

Freshwater planarians are a powerful model organism for the study of animal regeneration, stem cell maintenance and differentiation, and the development and functions of several highly conserved complex tissues. At the same time, planarians are easy to maintain, inexpensive to propagate, and reasonably macroscopic (1 mm to 1 cm in length), making them excellent organisms to use in both complex academic research and hands-on teaching laboratories. Here, we provide a detailed description of how to maintain and propagate these incredibly versatile animals in any basic laboratory setting. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Salt solution preparation Basic Protocol 2: Cleaning planarian housing Basic Protocol 3: Food preparation Basic Protocol 4: Feeding planarians Basic Protocol 5: Expansion and amplification of colony.

Multiplex reverse transcription loop-mediated isothermal amplification combined with nanoparticle-based lateral flow biosensor for the diagnosis of COVID-19

The ongoing global pandemic (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a huge public health issue. Hence, we devised a multiplex reverse transcription loop-mediated isothermal amplification (mRT-LAMP) coupled with a nanoparticle-based lateral flow biosensor (LFB) assay (mRT-LAMP-LFB) for diagnosing COVID-19. Using two LAMP primer sets, the ORF1ab (opening reading frame 1a/b) and N (nucleoprotein) genes of SARS-CoV-2 were simultaneously amplified in a single-tube reaction, and detected with the diagnosis results easily interpreted by LFB. In presence of FITC (fluorescein)-/digoxin- and biotin-labeled primers, mRT-LAMP produced numerous FITC-/digoxin- and biotin-attached duplex amplicons, which were determined by LFB through immunoreactions (FITC/digoxin on the duplex and anti-FITC/digoxin on the test line of LFB) and biotin/treptavidin interaction (biotin on the duplex and strptavidin on the polymerase nanoparticle). The accumulation of nanoparticles leaded a characteristic crimson band, enabling multiplex analysis of ORF1ab and N gene without instrumentation. The limit of detection (LoD) of COVID-19 mRT-LAMP-LFB was 12 copies (for each detection target) per reaction, and no cross-reactivity was generated from non-SARS-CoV-2 templates. The analytical sensitivity of SARS-CoV-2 was 100% (33/33 oropharynx swab samples collected from COVID-19 patients), and the assay's specificity was also 100% (96/96 oropharynx swab samples collected from non-COVID-19 patients). The total diagnostic test can be completed within 1 h from sample collection to result interpretation. In sum, the COVID-19 mRT-LAMP-LFB assay is a promising tool for diagnosing SARS-CoV-2 infections in frontline public health field and clinical laboratories, especially from resource-poor regions.

Detection of COVID-19: A review of the current literature and future perspectives

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the coronavirus disease 2019 (COVID-19) worldwide pandemic. This unprecedented situation has garnered worldwide attention. An effective strategy for controlling the COVID-19 pandemic is to develop highly accurate methods for the rapid identification and isolation of SARS-CoV-2 infected patients. Many companies and institutes are therefore striving to develop effective methods for the rapid detection of SARS-CoV-2 ribonucleic acid (RNA), antibodies, antigens, and the virus. In this review, we summarize the structure of the SARS-CoV-2 virus, its genome and gene expression characteristics, and the current progression of SARS-CoV-2 RNA, antibodies, antigens, and virus detection. Further, we discuss the reasons for the observed false-negative and false-positive RNA and antibody detection results in practical clinical applications. Finally, we provide a review of the biosensors which hold promising potential for point-of-care detection of COVID-19 patients. This review thereby provides general guidelines for both scientists in the biosensing research community and for those in the biosensor industry to develop a highly sensitive and accurate point-of-care COVID-19 detection system, which would be of enormous benefit for controlling the current COVID-19 pandemic.

Multiplex reverse transcription loop-mediated isothermal amplification combined with nanoparticle-based lateral flow biosensor for the diagnosis of COVID-19

The ongoing global pandemic (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a huge public health issue. Hence, we devised a multiplex reverse transcription loop-mediated isothermal amplification (mRT-LAMP) coupled with a nanoparticle-based lateral flow biosensor (LFB) assay (mRT-LAMP-LFB) for diagnosing COVID-19. Using two LAMP primer sets, the ORF1ab (opening reading frame 1a/b) and N (nucleoprotein) genes of SARS-CoV-2 were simultaneously amplified in a single-tube reaction, and detected with the diagnosis results easily interpreted by LFB. In presence of FITC (fluorescein)-/digoxin- and biotin-labeled primers, mRT-LAMP produced numerous FITC-/digoxin- and biotin-attached duplex amplicons, which were determined by LFB through immunoreactions (FITC/digoxin on the duplex and anti-FITC/digoxin on the test line of LFB) and biotin/treptavidin interaction (biotin on the duplex and strptavidin on the polymerase nanoparticle). The accumulation of nanoparticles leaded a characteristic crimson band, enabling multiplex analysis of ORF1ab and N gene without instrumentation. The limit of detection (LoD) of COVID-19 mRT-LAMP-LFB was 12 copies (for each detection target) per reaction, and no cross-reactivity was generated from non-SARS-CoV-2 templates. The analytical sensitivity of SARS-CoV-2 was 100% (33/33 oropharynx swab samples collected from COVID-19 patients), and the assay's specificity was also 100% (96/96 oropharynx swab samples collected from non-COVID-19 patients). The total diagnostic test can be completed within 1 h from sample collection to result interpretation. In sum, the COVID-19 mRT-LAMP-LFB assay is a promising tool for diagnosing SARS-CoV-2 infections in frontline public health field and clinical laboratories, especially from resource-poor regions.

Human virus detection with graphene-based materials

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.

PCR past, present and future

PCR has become one of the most valuable techniques currently used in bioscience, diagnostics and forensic science. Here we review the history of PCR development and the technologies that have evolved from the original PCR method. Currently, there are two main areas of PCR utilization in bioscience: high-throughput PCR systems and microfluidics-based PCR devices for point-of-care (POC) applications. We also discuss the commercialization of these techniques and conclude with a look into their modifications and use in innovative areas of biomedicine. For example, real-time reverse transcription PCR is the gold standard for SARS-CoV-2 diagnoses. It could also be used for POC applications, being a key component of the sample-to-answer system.

Brief validation of the novel GeneXpert Xpress SARS-CoV-2 PCR assay

The clinical and epidemiologic management of the SARS-CoV-2 pandemic is critically dependent on molecular assays with short turn-around time. We validated the novel Xpert Xpress SARS-CoV-2 assay using a commercial nucleic acid testing (Roche Cobas 6800). We found an excellent concordance over a range of SARS-CoV-2 loads and across established human coronaviruses.

A role for Biofoundries in rapid development and validation of automated SARS-CoV-2 clinical diagnostics

The SARS-CoV-2 pandemic has shown how a rapid rise in demand for patient and community sample testing can quickly overwhelm testing capability globally. With most diagnostic infrastructure dependent on specialized instruments, their exclusive reagent supplies quickly become bottlenecks, creating an urgent need for approaches to boost testing capacity. We address this challenge by refocusing the London Biofoundry onto the development of alternative testing pipelines. Here, we present a reagent-agnostic automated SARS-CoV-2 testing platform that can be quickly deployed and scaled. Using an in-house-generated, open-source, MS2-virus-like particle (VLP) SARS-CoV-2 standard, we validate RNA extraction and RT-qPCR workflows as well as two detection assays based on CRISPR-Cas13a and RT-loop-mediated isothermal amplification (RT-LAMP). In collaboration with an NHS diagnostic testing lab, we report the performance of the overall workflow and detection of SARS-CoV-2 in patient samples using RT-qPCR, CRISPR-Cas13a, and RT-LAMP. The validated RNA extraction and RT-qPCR platform has been installed in NHS diagnostic labs, increasing testing capacity by 1000 samples per day.

A Wearable Stethoscope for Long-Term Ambulatory Respiratory Health Monitoring

Lung sounds acquired by stethoscopes are extensively used in diagnosing and differentiating respiratory diseases. Although an extensive know-how has been built to interpret these sounds and identify diseases associated with certain patterns, its effective use is limited to individual experience of practitioners. This user-dependency manifests itself as a factor impeding the digital transformation of this valuable diagnostic tool, which can improve patient outcomes by continuous long-term respiratory monitoring under real-life conditions. Particularly patients suffering from respiratory diseases with progressive nature, such as chronic obstructive pulmonary diseases, are expected to benefit from long-term monitoring. Recently, the COVID-19 pandemic has also shown the lack of respiratory monitoring systems which are ready to deploy in operational conditions while requiring minimal patient education. To address particularly the latter subject, in this article, we present a sound acquisition module which can be integrated into a dedicated garment; thus, minimizing the role of the patient for positioning the stethoscope and applying the appropriate pressure. We have implemented a diaphragm-less acousto-electric transducer by stacking a silicone rubber and a piezoelectric film to capture thoracic sounds with minimum attenuation. Furthermore, we benchmarked our device with an electronic stethoscope widely used in clinical practice to quantify its performance.

Pandemic printing: a novel 3D-printed swab for detecting SARS-CoV-2

OBJECTIVES

To design and evaluate 3D-printed nasal swabs for collection of samples for SARS-CoV-2 testing.

DESIGN

An iterative design process was employed. Laboratory evaluation included in vitro assessment of mock nasopharyngeal samples spiked with two different concentrations of gamma-irradiated SARS-CoV-2. A prospective clinical study compared SARS-CoV-2 and human cellular material recovery by 3D-printed swabs and standard nasopharyngeal swabs.

SETTING, PARTICIPANTS

Royal Melbourne Hospital, May 2020. Participants in the clinical evaluation were 50 hospital staff members attending a COVID-19 screening clinic and two inpatients with laboratory-confirmed COVID-19.

INTERVENTION

In the clinical evaluation, a flocked nasopharyngeal swab sample was collected with the Copan ESwab and a mid-nasal sample from the other nostril was collected with the 3D-printed swab.

RESULTS

In the laboratory evaluation, qualitative agreement with regard to SARS-CoV-2 detection in mock samples collected with 3D-printed swabs and two standard swabs was complete. In the clinical evaluation, qualitative agreement with regard to RNase P detection (a surrogate measure of adequate collection of human cellular material) in samples collected from 50 hospital staff members with standard and 3D-printed swabs was complete. Qualitative agreement with regard to SARS-CoV-2 detection in three pairs of 3D-printed mid-nasal and standard swab samples from two inpatients with laboratory-confirmed SARS-CoV-2 was also complete.

CONCLUSIONS

Using 3D-printed swabs to collect nasal samples for SARS-CoV-2 testing is feasible, acceptable to patients and health carers, and convenient.

The impact of biosensing in a pandemic outbreak: COVID-19

COVID-19 pandemic outbreak is the most astounding scene ever experienced in the XXI century. In this opinionated review, we underscore the crucial role of biosensing to handle with such situations. As a matter of fact, testing accelerates life-saving decisions on treatment and isolation of COVID-19 patients in an early stage, and thereby, decelerating or even preventing the spread of such emerging infectious diseases. Meanwhile, it is also proven that a timely and broad application of testing leads to lower mortality rates in countries like Germany or South Korea. Besides, biosensors are also powerful tools for effective assessment of clinical progress and to provide alertness on severity or critical trends of infection. In view hereof, we critically discuss the state-of-the-art biosensing devices for COVID-19 testing. We spot the urgent needs and highlight innovative diagnostic approaches for targeting various COVID-19 related biomarkers. Finally, we outline our recommendations on biosensors and biosensing-related issues towards pandemic outbreaks.

Open Development and Clinical Validation of Multiple 3D-Printed Nasopharyngeal Collection Swabs: Rapid Resolution of a Critical COVID-19 Testing Bottleneck

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a severe international shortage of the nasopharyngeal swabs that are required for collection of optimal specimens, creating a critical bottleneck blocking clinical laboratories' ability to perform high-sensitivity virological testing for SARS-CoV-2. To address this crisis, we designed and executed an innovative, cooperative, rapid-response translational-research program that brought together health care workers, manufacturers, and scientists to emergently develop and clinically validate new swabs for immediate mass production by 3D printing. We performed a multistep preclinical evaluation of 160 swab designs and 48 materials from 24 companies, laboratories, and individuals, and we shared results and other feedback via a public data repository (http://github.com/rarnaout/Covidswab/). We validated four prototypes through an institutional review board (IRB)-approved clinical trial that involved 276 outpatient volunteers who presented to our hospital's drive-through testing center with symptoms suspicious for COVID-19. Each participant was swabbed with a reference swab (the control) and a prototype, and SARS-CoV-2 reverse transcriptase PCR (RT-PCR) results were compared. All prototypes displayed excellent concordance with the control (κ = 0.85 to 0.89). Cycle threshold (CT ) values were not significantly different between each prototype and the control, supporting the new swabs' noninferiority (Mann-Whitney U [MWU] test, P > 0.05). Study staff preferred one of the prototypes over the others and preferred the control swab overall. The total time elapsed between identification of the problem and validation of the first prototype was 22 days. Contact information for ordering can be found at http://printedswabs.org Our experience holds lessons for the rapid development, validation, and deployment of new technology for this pandemic and beyond.

Clinical evaluation of a SARS-CoV-2 RT-PCR assay on a fully automated system for rapid on-demand testing in the hospital setting

BACKGROUND

The ongoing SARS-CoV-2 pandemic presents a unique challenge for diagnostic laboratories around the world. Automation of workflows in molecular diagnostics is instrumental for coping with the large number of tests ordered by clinicians, as well as providing fast-tracked rapid testing for highly urgent cases. In this study we evaluated a SARS-CoV-2 LDT for the NeuMoDx 96 system, a fully automated device performing extraction and real-time PCR.

METHODS

A publicly available SARS-CoV-2 RT-PCR assay was adapted for the automated system. Analytical performance was evaluated using in-vitro transcribed RNA and clinical performance was compared to the cobas 6800-based reference assay within the lab.

RESULTS

The Envelope (E) Gene-LDT displayed good analytical performance with an LoD of 95.55 cp/mL and no false positives during evaluation of cross-reactivity. A total of 176 patient samples were tested with both the E-Gene-LDT and the reference assay. Positive and negative agreement were 100 % and 99.2 % respectively. Invalid-rate was 6.3 %.

CONCLUSION

The E-Gene-LDT showed analytical and clinical performance comparable to the cobas6800-based reference assay. Due to its random-access workflow concept and rapid time-to-result of about 80 min, the system is very well suited for providing fast-tracked SARS-CoV-2 diagnostics for urgent clinical samples in the hospital setting.

Diagnostic accuracy of the FebriDx host response point-of-care test in patients hospitalised with suspected COVID-19

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Centralised laboratory PCR testing for COVID-19 is associated with long delays.

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The FebriDx POCT can detect an antiviral host response protein (MxA) in 10 min.

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We evaluated the diagnostic accuracy of FebriDx in 251 patients hospitalised with suspected COVID-19 during the first wave.

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Compared to PCR sensitivity of FebriDx was 93% and specificity was 86%.

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FebriDx could be used as a rapid front door triage tool in hospitals.

Introduction

Management 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.

Methods

We 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.

Results

FebriDx 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.

Conclusions

During 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 registration

ISRCTN14966673

Multicentre comparison of quantitative PCR-based assays to detect SARS-CoV-2, Germany, March 2020

Containment strategies and clinical management of coronavirus disease (COVID-19) patients during the current pandemic depend on reliable diagnostic PCR assays for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we compare 11 different RT-PCR test systems used in seven diagnostic laboratories in Germany in March 2020. While most assays performed well, we identified detection problems in a commonly used assay that may have resulted in false-negative test results during the first weeks of the pandemic.

Development of an ergonomic four-finger-push manual pipette design

The purpose of this study was to develop a new pipette design in which the pipette is operated by four fingers, taking into account the anatomy and anthropometry of the hand. The proposed new pipette designs were compared with a traditional thumb-push pipette based on muscle activity, wrist posture, subjective discomfort ratings for upper extremities, and user preference. The results of the study revealed that the four-finger, ergonomic pipette design reduced muscle exertion (25% reduction for aspiration and 35% reduction for dispensing), awkward wrist posture (33% reduction in wrist flexion, radial and ulnar deviation), and perceived discomfort in the wrist, hand and lower arm. Furthermore, most participants (9 of 10) who used a pipette in their daily work preferred the new pipette designs to a traditional thumb-push pipette design. Thus, we expect that this study will contribute to the reduction of WMSDs risk factors and pain.

Determination of Albumin, Glucose, and Creatinine Employing a Single Sequential Injection Lab-at-Valve with Mono-Segmented Flow System Enabling In-Line Dilution, In-Line Single-Standard Calibration, and In-Line Standard Addition

A mono-segmented sequential injection lab-at-valve (SI-LAV) system for the determination of albumin, glucose, and creatinine, three key biomarkers in diabetes screening and diagnosis, was developed as a single system for multi-analyte analysis. The mono-segmentation technique was employed for in-line dilution, in-line single-standard calibration, and in-line standard addition. This made adjustments to the sample preparation step easy unlike the batch-wise method. The results showed that the system could be used for both fast reaction (albumin) and slow reaction (glucose with enzymatic reaction and creatinine). In the case of slow reaction, the analysis time could be shortened by using the reaction rate obtained with the SI-LAV system. This proposed system is for cost-effective and downscaling analysis, which would be applicable for small hospitals and clinics in remote places with a small number of samples but relatively fast screening would be needed.

Structure-dependent retention of steroid hormones by common laboratory materials

The tendency of steroid molecules to adsorb to various materials, particularly plastics, has been known of for decades but has not received widespread attention in the scientific community, and a modern, systematic study is lacking. This adsorption is an important consideration for researchers working with steroid hormones as it could skew the results of various experiments. Here we show that steroids adsorb to various vessels used in experiments, including microcentrifuge tubes, glass vials, and cell culture plates, in a manner that depends on the steroid's molecular structure and on the type of vessel. The lipophilicity of steroids is a strong predictor of the degree of adsorption, with nearly 50 % of the most lipophilic steroid tested, pregnenolone, retained in a high-adsorbing microcentrifuge tube after one hour incubation of an aqueous pregnenolone solution followed by removal of the aqueous solvent. We also show the effects of other factors such as incubation time, centrifugation, and temperature on adsorption, and show that adsorption can be mostly prevented by the presence of serum proteins in steroid solutions and/or by the use of low-adsorbing tubes.

A Pre-Analytical Performance Evaluation for Measurement of Serum Creatinine in a Multicenter Clinical Trial Study

BACKGROUND

Our multicenter clinical trial study for stage 4 chronic kidney disease (CKD) populations was conducted at 21 centers in China during the period 2011 to 2016. The CKD definition is based on glomerular filtration rate (GFR) values which can be estimated by creatinine-based predictive formulas. The validity and reliability of GFR estimation is thus largely dependent on the accurate and precise serum creatinine (SCr) measurements. As an integral part of this multicenter study, it is important to ensure the precision, accuracy, and center-to-center comparability of the SCr results.

METHODS

Prior to initiating the study, we unified the measurement method of SCr determination as an enzymatic method and standardized the procedure in all of the laboratories. Then, the analytical performance of each analyzer at each laboratory was evaluated, including precision, accuracy, and comparability.

RESULTS

All within-run and total CVs of the low and high level internal quality control (IQC) were comprised between 0.2% and 4.1% (< 1/3 CLIA'88). Total error of the IQC fall within the maximum 12% at all centers. The analytical bias against the Standard Reference material 967a target was less than ± 0.5% at Central Laboratory, indicating good accuracy. Correlation between the analyzers and the reference method were very high (r > 0.99). Passing-Bablok regression showed no significant deviation from linearity (p > 0.05). Bland-Altman analysis also showed good agreement (≥ 95% of results fell within the 95% limits of agreement).

CONCLUSIONS

Performance evaluation helped in addressing preanalytical variations in measurement and gave op-timal quality assurance of laboratory measurement in the context of a multicenter clinical trial study.

Fractured aluminum nasopharyngeal swab during drive-through testing for COVID-19: radiographic detection of a retained foreign body

The ongoing coronavirus disease 2019 (COVID-19) pandemic has increased the need for safe and efficient testing as a key containment strategy. Drive-through testing with nasopharyngeal swab has been implemented in many places in the USA as it allows for expeditious testing of large numbers of patients, limits healthcare workers' risk of exposure, and minimizes the use of personal protective equipment. We present a case where the aluminum shaft of the nasopharyngeal swab fractured during specimen collection at a drive-through testing facility and was suspected to have remained in the asymptomatic patient. Initial evaluation with a series of radiographs covering the skull base, neck, chest, and abdomen did not reveal the swab. On further clinical evaluation, the swab was found endoscopically, lodged between the left inferior turbinate and nasal floor, and was removed by an otorhinolaryngologist. Using a phantom model, we aimed to delineate an imaging technique to better visualize the aluminum shaft of the nasopharyngeal swab on radiographs to help in identification. A technique using lower tube voltage (kVp) with tight collimation centered at the nasal bones area produced the best visualization of the aluminum shaft of the swab. Recognition that aluminum foreign bodies may be difficult to visualize radiographically and  optimization of radiograph acquisition technique may help guide clinical management in unusual cases. Further evaluation with computed tomography or endoscopy should be considered in suspected cases where radiographs are negative.

Too old to test? Prevalence and correlates of HIV testing among sexually active older adults

Older adults account for 17% of new HIV diagnoses in the US and are more likely to be diagnosed with HIV later in the course of the disease compared to younger people. We calculated the prevalence and associated factors of having ever been tested for HIV among sexually active older adults. We analyzed data from the 2008-2016 General Social Survey Limited to respondents ≥65 years of age who reported more than one sex partner(s) in past 12 months (n = 757). HIV testing prevalence, prevalence ratios, and 95% confidence intervals were calculated by demographic variables and HIV-related risk behaviors. An estimated 16.3% of sexually active older adults have tested for HIV, and 15.9% were at increased risk for HIV infection (reported injection drug and/or crack-cocaine use, exchanging money for sex, more than three sex partners in the past year, or men who reported having sex with another man). In the adjusted model, adults aged 65-70, not married, self-identified as gay/bisexual, and at increased risk for HIV infection were more likely to have tested for HIV. An estimated 83.7% of sexually active older adults never tested for HIV. Strategies are needed to increase HIV awareness and testing among potentially high-risk older adults.

Latent class analysis to evaluate performance of point-of-care CCA for low-intensity Schistosoma mansoni infections in Burundi

BACKGROUND

Kato-Katz examination of stool smears is the field-standard method for detecting Schistosoma mansoni infection. However, Kato-Katz misses many active infections, especially of light intensity. Point-of-care circulating cathodic antigen (CCA) is an alternative field diagnostic that is more sensitive than Kato-Katz when intensity is low, but interpretation of CCA-trace results is unclear. To evaluate trace results, we tested urine and stool specimens from 398 pupils from eight schools in Burundi using four approaches: two in Burundi and two in a laboratory in Leiden, the Netherlands. In Burundi, we used Kato-Katz and point-of-care CCA (CCAB). In Leiden, we repeated the CCA (CCAL) and also used Up-Converting Phosphor Circulating Anodic Antigen (CAA).

METHODS

We applied Bayesian latent class analyses (LCA), first considering CCA traces as negative and then as positive. We used the LCA output to estimate validity of the prevalence estimates of each test in comparison to the population-level infection prevalence and estimated the proportion of trace results that were likely true positives.

RESULTS

Kato-Katz yielded the lowest prevalence (6.8%), and CCAB with trace considered positive yielded the highest (53.5%). There were many more trace results recorded by CCA in Burundi (32.4%) than in Leiden (2.3%). Estimated prevalence with CAA was 46.5%. LCA indicated that Kato-Katz had the lowest sensitivity: 15.9% [Bayesian Credible Interval (BCI): 9.2-23.5%] with CCA-trace considered negative and 15.0% with trace as positive (BCI: 9.6-21.4%), implying that Kato-Katz missed approximately 85% of infections. CCAB underestimated disease prevalence when trace was considered negative and overestimated disease prevalence when trace was considered positive, by approximately 12 percentage points each way, and CAA overestimated prevalence in both models. Our results suggest that approximately 52.2% (BCI: 37.8-5.8%) of the CCAB trace readings were true infections.

CONCLUSIONS

Whether measured in the laboratory or the field, CCA outperformed Kato-Katz at the low infection intensities in Burundi. CCA with trace as negative likely missed many infections, whereas CCA with trace as positive overestimated prevalence. In the absence of a field-friendly gold standard diagnostic, the use of a variety of diagnostics with differing properties will become increasingly important as programs move towards elimination of schistosomiasis. It is clear that CCA is a valuable tool for the detection and mapping of S. mansoni infection in the field and CAA may be a valuable field tool in the future.

The power of solid supports in multiphase and droplet-based microfluidics: towards clinical applications

Multiphase and droplet microfluidic systems are growing in relevance in bioanalytical-related fields, especially due to the increased sensitivity, faster reaction times and lower sample/reagent consumption of many of its derived bioassays. Often applied to homogeneous (liquid/liquid) reactions, innovative strategies for the implementation of heterogeneous (typically solid/liquid) processes have recently been proposed. These involve, for example, the extraction and purification of target analytes from complex matrices or the implementation of multi-step protocols requiring efficient washing steps. To achieve this, solid supports such as functionalized particles (micro or nanometric) presenting different physical properties (e.g. magnetic, optical or others) are used for the binding of specific entities. The manipulation of such supports with different microfluidic principles has both led to the miniaturization of existing biomedical protocols and the development of completely new strategies for diagnostics and research. In this review, multiphase and droplet-based microfluidic systems using solid suspensions are presented and discussed with a particular focus on: i) working principles and technological developments of the manipulation strategies and ii) applications, critically discussing the level of maturity of these systems, which can range from initial proofs of concept to real clinical validations.

[Clinical governance and patient safety culture in clinical laboratories in the Spanish National Health System]

AIM

To conduct a situational analysis of patient safety culture in public laboratories in the Spanish National Health System and to determine the clinical governance variables that most strongly influence patient safety.

METHOD

A descriptive cross-sectional study was carried out, in which a Survey of Patient Safety in Clinical Laboratories was addressed to workers in 26 participating laboratories. In this survey, which consisted of 45 items grouped into 6 areas, scores were assigned on a scale from 0 to 100 (where 0 is the lowest perception of patient safety). Laboratory managers were asked specific questions about quality management systems and technology.

RESULTS

The mean scores for the 26 participating hospitals were evaluated, and the following results observed: in 4of the 6areas, the mean score was higher than 70 points. In the third area (equipment and resources) and the fourth area (working conditions), the scores were lower than 60 points. Every hospital had a digital medical record system. This 100% level of provision was followed by that of an electronic request management system, which was implemented in 82.6% of the hospitals.

CONCLUSIONS

The results obtained show that the culture of security is homogeneous and of high quality in health service laboratories, probably due to the steady improvement observed. However, in terms of clinical governance, there is still some way to go, as shown by the presence of weaknesses in crucial dimensions of safety culture, together with variable levels of implementation of fail-safe technologies and quality management systems.

Clinical Laboratory Improvement Amendments of 1988 (CLIA); Fecal Occult Blood (FOB) Testing. Final rule

This final rule amends the Clinical Laboratory Improvement Amendments of 1988 (CLIA) regulations to clarify that the waived test categorization applies only to non-automated fecal occult blood tests.

[ESTIMATE OF THE INTRINSIC ERROR OF THE MEASURING INSTRUMENT OF THE LABORATORY FOR ANALYTICAL DETERMINATIONS OF THE CRITICAL PATIENT]

Decrease blood loss associated with the analytical laboratory is a determinant of safety and quality in the preanalytical phase, in order to achieve an optimal level of care, where nurses have leading role to be responsible for the care of the critically ill patient.

Clinical instrumentation and applications of Raman spectroscopy

Clinical diagnostic devices provide new sources of information that give insight about the state of health which can then be used to manage patient care. These tools can be as simple as an otoscope to better visualize the ear canal or as complex as a wireless capsule endoscope to monitor the gastrointestinal tract. It is with tools such as these that medical practitioners can determine when a patient is healthy and to make an appropriate diagnosis when he/she is not. The goal of diagnostic medicine then is to efficiently determine the presence and cause of disease in order to provide the most appropriate intervention. The earliest form of medical diagnostics relied on the eye - direct visual observation of the interaction of light with the sample. This technique was espoused by Hippocrates in his 5th century BCE work Epidemics, in which the pallor of a patient's skin and the coloring of the bodily fluids could be indicative of health. In the last hundred years, medical diagnosis has moved from relying on visual inspection to relying on numerous technological tools that are based on various types of interaction of the sample with different types of energy - light, ultrasound, radio waves, X-rays etc. Modern advances in science and technology have depended on enhancing technologies for the detection of these interactions for improved visualization of human health. Optical methods have been focused on providing this information in the micron to millimeter scale while ultrasound, X-ray, and radio waves have been key in aiding in the millimeter to centimeter scale. While a few optical technologies have achieved the status of medical instruments, many remain in the research and development phase despite persistent efforts by many researchers in the translation of these methods for clinical care. Of these, Raman spectroscopy has been described as a sensitive method that can provide biochemical information about tissue state while maintaining the capability of delivering this information in real-time, non-invasively, and in an automated manner. This review presents the various instrumentation considerations relevant to the clinical implementation of Raman spectroscopy and reviews a subset of interesting applications that have successfully demonstrated the efficacy of this technique for clinical diagnostics and monitoring in large (n ≥ 50) in vivo human studies.

[Progress of researches on diagnostic methods of current Schistosoma infection]

Now schistosomiasis is still a serious zoonosis which affects human health and hinders the economy development in endemic areas. Accurate diagnosis of the infection of Schistosoma is very significant in reducing hazards to human health and controlling the epidemic of schistosomiasis. This review summarizes recent advances in the laboratory diagnostic methods for current schistosome infection (including pathogenic, immunologic and molecular biologic methods) so as to provide the reference for prevention and control of schistosomiasis in the field.

[Quality analysis of malaria blood smear preparations of febrile patients in Chenzhou Prefecture, 2014]

OBJECTIVE

To standardize the malaria smear preparations of febrile patients in Chenzhou Prefecture, Hunan Province, so as to provide the technical support for malaria elimination.

METHODS

According to the Technical Solutions to Eliminate Malaria (2011 edition) , the blood smear preparations of febrile patients from each county, included more than 3% negatives and all positives, were reviewed monthly in 2014. The quality of blood smear manufacture, dyeing, cleanliness and results was reviewed by malaria microscopic examination experts. The data were analyzed with the descriptive epidemiological methods.

RESULTS

Totally 231 blood smears were reviewed in 2014 with a reviewed rate of 6.91%. The blood smear production qualified rate was 80.52%, the dyeing pass rate was 84.42%, the cleanliness pass rate was 86.58%, and there were no false detections and no leak detections. The highest blood smear production qualified rate, dyeing pass rate and cleanliness pass rate were found in Guiyang County and Linwu County, with all the rates of 100% respectively. The lowest blood smear production qualified rate and cleanliness pass rate were found in Yizhang County, with the rates of 52.94 % and 70.59% respectively. The lowest blood smear dyeing pass rate was found in Yongxing County with the rate of 63.64%. There were statistically significant differences between Guiyang County and Yizhang County in the production qualified rates and cleanliness pass rates (χ2 = 18.60, 9.73, both P < 0.01). There was a statistically significant difference between Guiyang County and Yongxing County in the dyeing pass rates (χ2 = 11.43, P < 0.01).

CONCLUSION

Through the review of blood smears, the problems will be timely discovered. Therefore, the blood smear quality should improve, which is helpful for achieving the goal of malaria elimination.

Effects of Aggregation on Blood Sedimentation and Conductivity

The erythrocyte sedimentation rate (ESR) test has been used for over a century. The Westergren method is routinely used in a variety of clinics. However, the mechanism of erythrocyte sedimentation remains unclear, and the 60 min required for the test seems excessive. We investigated the effects of cell aggregation during blood sedimentation and electrical conductivity at different hematocrits. A sample of blood was drop cast into a small chamber with two planar electrodes placed on the bottom. The measured blood conductivity increased slightly during the first minute and decreased thereafter. We explored various methods of enhancing or retarding the erythrocyte aggregation. Using experimental measurements and theoretical calculations, we show that the initial increase in blood conductivity was indeed caused by aggregation, while the subsequent decrease in conductivity resulted from the deposition of erythrocytes. We present a method for calculating blood conductivity based on effective medium theory. Erythrocytes are modeled as conducting spheroids surrounded by a thin insulating membrane. A digital camera was used to investigate the erythrocyte sedimentation behavior and the distribution of the cell volume fraction in a capillary tube. Experimental observations and theoretical estimations of the settling velocity are provided. We experimentally demonstrate that the disaggregated cells settle much slower than the aggregated cells. We show that our method of measuring the electrical conductivity credibly reflected the ESR. The method was very sensitive to the initial stage of aggregation and sedimentation, while the sedimentation curve for the Westergren ESR test has a very mild slope in the initial time. We tested our method for rapid estimation of the Westergren ESR. We show a correlation between our method of measuring changes in blood conductivity and standard Westergren ESR method. In the future, our method could be examined as a potential means of accelerating ESR tests in clinical practice.

A toolkit for clinical statisticians to fix problems based on biomarker measurements subject to instrumental limitations: from repeated measurement techniques to a hybrid pooled-unpooled design

The aim of this chapter is to review and examine different methods in order to display correct and efficient statistical techniques based on complete/incomplete data subject to different sorts of measurement error (ME) problems. Instrument inaccuracies, biological variations, and/or errors in questionnaire-based self-report data can lead to significant MEs in various clinical experiments. Ignoring MEs can cause bias or inconsistency of statistical inferences. The biostatistical literature well addresses two categories of MEs: errors related to additive models and errors caused by the limit of detection (LOD). Several statistical approaches have been developed to analyze data affected by MEs, including the parametric/nonparametric likelihood methodologies, Bayesian methods, the single and multiple imputation techniques, and the repeated measurement design of experiment. We present a novel hybrid pooled-unpooled design as one of the strategies to provide correct statistical inferences when data is subject to MEs. This hybrid design and the classical techniques are compared to show the advantages and disadvantages of the considered methods.

[How Far We can Diagnose by Urine Sediment Tests?]

Morphological examinations for renal disease are mainly renal biopsy and urine sediment tests. Biopsy specimens are now evaluated in detail, and test items are evaluated as highly sensitive and specific compared with urine sediments, which reflect renal changes indirectly and are low in sensitivity and specificity. On the other hand, the standardization of urine sediment tests is now in progress, and some labs can provide sediment results beyond screening for distracted RBC, differential WBC, or atypical cells. The diagnostic importance of sediments is revisited.

Next generation platforms for high-throughput biodosimetry

Here the general concept of the combined use of plates and tubes in racks compatible with the American National Standards Institute/the Society for Laboratory Automation and Screening microplate formats as the next generation platforms for increasing the throughput of biodosimetry assays was described. These platforms can be used at different stages of biodosimetry assays starting from blood collection into microtubes organised in standardised racks and ending with the cytogenetic analysis of samples in standardised multiwell and multichannel plates. Robotically friendly platforms can be used for different biodosimetry assays in minimally equipped laboratories and on cost-effective automated universal biotech systems.

[The comparative characteristic of methods of laboratory diagnostic of opisthorchiasis]

The analysis of samples of blood serums and copromaterial from patients was carried out to evaluate effectiveness of diagnostic of opisthorchiasis invasion. The Kato-Miura technique of thick film under cellophane layer and sedimentation technique of acetic etheric precipitation were applied for parasitologic diagnostic. The technique of immunoenzymometric analysis was applied for serological diagnostic. The analysis of detection rate of eggs of opistorchis in copromaterial and level of anti-opistorchis antibodies in samples of blood serum of patients demonstrated the presence of strong direct correlation relationship between these indicators. It is demonstrated that for laboratory diagnostic of opisthorchiasis it is impossible to limit oneself to some single technique. It is established that on the territories with middle and low level of population infection rate of opistorchis it is appropriate to apply complex of methods including analysis of blood serum for presence of specific immunoglobulins to antigens of opistorchis and twice or thrice analysis of feces with copro-ovoscopic methods.