Risk of cancer and serious disease in Danish patients with urgent referral for serious non-specific symptoms and signs of cancer in Funen 2014-2021

BACKGROUND

In 2011, as the first European country, Denmark introduced the non-organ-specific cancer patient pathway (CPP) for patients presenting with non-specific symptoms and signs of cancer (NSSC). The proportion of patients with cancer over time is unknown.

METHODS

A retrospective cohort study of all patients with a NSSC-CPP investigational course in the province of Funen to the Diagnostic Centre in Svendborg from 2014 to 2021 was performed to evaluate the proportion of patients with cancer and serious disease over time.

RESULTS

A total of 6698 patients were referred to the NSSC-CPP of which 20.2% had cancer. While the crude referral rate increased from 114 per 100,000 people in 2014 and stabilised to around 214 in 2017-2021, the cancer detection rate of the total yearly new cancers in Funen diagnosed through the NSSC-CPP in DC Svendborg increased from 3 to 6%.

CONCLUSIONS

With now high and stable conversion and crude referral rates, the NSSC-CPP is one of the largest CPPs in Denmark as measured by the number of new cancer cases found. Similar urgent referral programmes in other countries might fill an unmet medical need for patients presenting with serious non-specific symptoms and signs of cancer in general practice.

Clot time ratio (CTR) and treatment outcomes in Apixaban-treated atrial fibrillation patients

There are clinical situations where information about the anticoagulant effects of Apixaban could be useful. Specialised methods for measuring Apixaban concentrations are not available at all medical laboratories while methods for measuring the functional effects of Apixaban, using clot time ratio (CTR), can be performed in most medical laboratories around the clock using well-established measurement procedures. The aim of this study was to investigate CTR in trough and peak samples during Apixaban treatment of atrial fibrillation and to correlate the findings to bleeds and thrombotic events. Three trough- and three peak samples from 61 patients (31 on Apixaban 5 mg twice daily and 30 on Apixaban 2.5 mg twice daily) were analysed with MRX PT DOAC. Patients were followed for 30 + /-15 months, and bleeds and thrombotic events were documented. The effect of Apixaban could be measured with MRX PT DOAC and there was a statistically significant difference between CTR in trough samples compared to peak samples (p < 0.001). A total of 21 patients suffered bleeds during follow-up; two patients suffered major bleeds, and 19 suffered minor bleeds. Patients with major bleeds had both mean peak- and mean trough CTR above the respective first to third quartile (Q1-Q3) range. Four patients suffered thromboembolic events. Generally, the peak CTRs were below or in the lower end of the peak Q1-Q3 for these patients. The new test MRX PT DOAC can be used to measure the effect of Apixaban during the treatment of atrial fibrillation. High mean peak- and mean trough CTR were seen in 2 patients with major bleeds, and low peak CTR was seen in 4 patients with thromboembolic events.

Effect of hyperbilirubinemia on the accuracy of continuous non-invasive hemoglobin measurements in liver transplantation recipients

This study evaluated the effect of hyperbilirubinemia on the accuracy of continuous non-invasive hemoglobin (SpHb) measurements in liver transplantation recipients. Overall, 1465 SpHb and laboratory hemoglobin (Hb) measurement pairs (n = 296 patients) were analyzed. Patients were grouped into normal (< 1.2 mg/dL), mild-to-moderate (1.2-3.0 mg/dL), and severe (> 3.0 mg/dL) hyperbilirubinemia groups based on the preoperative serum total bilirubin levels. Bland-Altman analysis showed a bias of 0.20 (95% limit of agreement, LoA: - 2.59 to 3.00) g/dL, 0.98 (95% LoA: - 1.38 to 3.35) g/dL, and 1.23 (95% LoA: - 1.16 to 3.63) g/dL for the normal, mild-to-moderate, and severe groups, respectively. The four-quadrant plot showed reliable trending ability in all groups (concordance rate > 92%). The rates of possible missed transfusion (SpHb > 7.0 g/dL for Hb < 7.0 g/dL) were higher in the hyperbilirubinemia groups (2%, 7%, and 12% for the normal, mild-to-moderate, and severe group, respectively. all P < 0.001). The possible over-transfusion rate was less than 1% in all groups. In conclusion, the use of SpHb in liver transplantation recipients with preoperative hyperbilirubinemia requires caution due to the positive bias and high risk of missed transfusion. However, the reliable trending ability indicated its potential use in clinical settings.

A retrospective observational study of 1000 consecutive patients tested with the FilmArray® Meningitis/Encephalitis panel: clinical diagnosis at discharge and microbiological findings

FilmArray® Meningitis/Encephalitis panel (FAME-p) is used to diagnose central nervous system (CNS) infections. In this study, we investigated performance of FAME-p compared to comparator assays (CA), and for the first time, clinical diagnosis at discharge (CDD). 1000 consecutive patients with a cerebrospinal fluid (CSF) sample analyzed with FAME-p were identified. As CA, culture, polymerase chain reaction and cryptococcal antigen test were used. Medical records of patients were obtained. A CDD of CNS infection was made in 139 of 1000 CSF samples. FAME-p was positive in 66 samples with 44 viral and 22 bacterial agents. Thirteen FAME-p findings were not confirmed by CA, with four discrepant results remaining after comparison with the CDD. Positive percentage agreement (PPA) calculated against CA was 100%. Negative percentage agreement (NPA) calculated against CA was 94.4-99.8% for Haemophilus influenzae, Listeria monocytogenes, Streptococcus agalactiae, S. pneumoniae and varicella-zoster virus (VZV). NPA calculated against CDD was higher (compared to CA) for L. monocytogenes, S. agalactiae and VZV (100%), and lower for Escherichia coli, enterovirus and herpes simplex virus 2 (50-83.3%). NPA of FAME-p for human herpes virus 6 was difficult to interpret. Eighty-four cases received diagnosis of CNS-infection despite negative FAME-p. The four most common non-infectious etiologies were primary headache disorders, cranial nerve palsies, neuroinflammatory disorders and seizure. Although FAME-p shows good performance in diagnosis of CNS infections, result of FAME-p should be interpreted carefully. Considering infectious diseases not covered by FAME-p as well as non-infectious differential diagnoses is important in this context.

Early onset diagnosis in Alzheimer's disease patients via amyloid-β oligomers-sensing probe in cerebrospinal fluid

Amyloid-β (Aβ) oligomers are implicated in the onset of Alzheimer's disease (AD). Herein, quinoline-derived half-curcumin-dioxaborine (Q-OB) fluorescent probe was designed for detecting Aβ oligomers by finely tailoring the hydrophobicity of the biannulate donor motifs in donor-π-acceptor structure. Q-OB shows a great sensing potency in dynamically monitoring oligomerization of Aβ during amyloid fibrillogenesis in vitro. In addition, we applied this strategy to fluorometrically analyze Aβ self-assembly kinetics in the cerebrospinal fluids (CSF) of AD patients. The fluorescence intensity of Q-OB in AD patients' CSF revealed a marked change of log (I/I0) value of 0.34 ± 0.13 (cognitive normal), 0.15 ± 0.12 (mild cognitive impairment), and 0.14 ± 0.10 (AD dementia), guiding to distinguish a state of AD continuum for early diagnosis of AD. These studies demonstrate the potential of our approach can expand the currently available preclinical diagnostic platform for the early stages of AD, aiding in the disruption of pathological progression and the development of appropriate treatment strategies.

A digital image colorimetry system based on smart devices for immediate and simultaneous determination of enzyme-linked immunosorbent assays

Standard enzyme-linked immunosorbent assays based on microplates are frequently utilized for various molecular sensing, disease screening, and nanomedicine applications. Comparing this multi-well plate batched analysis to non-batched or non-standard testing, the diagnosis expenses per patient are drastically reduced. However, the requirement for rather big and pricey readout instruments prevents their application in environments with limited resources, especially in the field. In this work, a handheld cellphone-based colorimetric microplate reader for quick, credible, and novel analysis of digital images of human cancer cell lines at a reasonable price was developed. Using our in-house-developed app, images of the plates are captured and sent to our servers, where they are processed using a machine learning algorithm to produce diagnostic results. Using FDA-approved human epididymis protein of ovary IgG (HE4), prostate cancer cell line (PC3), and bladder cancer cell line (5637) ELISA tests, we successfully examined this mobile platform. The accuracies for the HE4, PC3, and 5637 tests were 93%, 97.5%, and 97.2%, respectively. By contrasting the findings with the measurements made using optical absorption EPOCH microplate readers and optical absorption Tecan microplate readers, this approach was found to be accurate and effective. As a result, digital image colorimetry on smart devices offered a practical, user-friendly, affordable, precise, and effective method for quickly identifying human cancer cell lines. Thus, healthcare providers might use this portable device to carry out high-throughput illness screening, epidemiological investigations or monitor vaccination campaigns.

Rapid and visual identification of β-lactamase subtypes for precision antibiotic therapy

The abuse of antibiotics urgently requires rapid identification of drug-resistant bacteria at the point of care (POC). Here we report a visual paper sensor that allows rapid (0.25-3 h) discrimination of the subtypes of β-lactamase (the major cause of bacterial resistance) for precision antibiotic therapy. The sensor exhibits high performance in identifying antibiotic-resistant bacteria with 100 real samples from patients with diverse bacterial infections, demonstrating 100% clinical sensitivity and specificity. Further, this sensor can enhance the accuracy of antibiotic use from 48% empirically to 83%, and further from 50.6% to 97.6% after eliminating fungal infection cases. Our work provides a POC testing platform for guiding effective management of bacterial infections in both hospital and community settings.

On the prediction of tibiofemoral contact forces for healthy individuals and osteoarthritis patients during gait: a comparative study of regression methods

Knee osteoarthritis (OA) is a public health problem affecting millions of people worldwide. The intensity of the tibiofemoral contact forces is related to cartilage degeneration, and so is the importance of quantifying joint loads during daily activities. Although simulation with musculoskeletal models has been used to calculate joint loads, it demands high-cost equipment and a very time-consuming process. This study aimed to evaluate consolidated machine learning algorithms to predict tibiofemoral forces during gait analysis of healthy individuals and knee OA patients. Also, we evaluated three different datasets to train each model, considering different combinations of primary kinematic and kinetic data, and post-processing data. We evaluated 14 patients with severe unilateral knee OA and 14 healthy individuals during 3-5 gait trials. Data were split into 70% and 30% of the samples as training and test data. Test data was independently evaluated considering a mixture of pathological and healthy individuals, and only OA and Control patients. The main results showed that accurate predictions of the tibiofemoral contact forces were achieved using machine learning methods and that the predictions were sensitive to changes in the input data as training. The present study provided insights into the most promising regressions methods to predict knee contact forces representing an important starting point for the broader application of biomechanical analysis in clinical environments.

Novel rapid method for identifying and quantifying pathogenic bacteria within four hours of blood collection

Sepsis is life-threatening organ dysfunction and is considered a major cause of health loss. However, since the current biomarkers of sepsis reflect the host's immune response to microorganisms, they would inevitably cause a time-lag. This means that there is still no truly reliable biomarker of sepsis. In the present study, we developed a novel method for identifying and quantifying unknown pathogenic bacteria within four hours of sample collection. The most important point of this study is that the novel method can be used to determine the number of bacteria in a sample as a novel biomarker of infectious diseases. Indeed, based on the number of bacteria, we were able to accurately estimate the severity of microbial infection. Furthermore, using the time-dependent changes in the number of bacteria, we were able to monitor the therapeutic effect accurately. The rapid identification and quantification of bacteria may change our approach to medical care.

Autonomous artificial intelligence increases screening and follow-up for diabetic retinopathy in youth: the ACCESS randomized control trial

Diabetic retinopathy can be prevented with screening and early detection. We hypothesized that autonomous artificial intelligence (AI) diabetic eye exams at the point-of-care would increase diabetic eye exam completion rates in a racially and ethnically diverse youth population. AI for Children's diabetiC Eye ExamS (NCT05131451) is a parallel randomized controlled trial that randomized youth (ages 8-21 years) with type 1 and type 2 diabetes to intervention (autonomous artificial intelligence diabetic eye exam at the point of care), or control (scripted eye care provider referral and education) in an academic pediatric diabetes center. The primary outcome was diabetic eye exam completion rate within 6 months. The secondary outcome was the proportion of participants who completed follow-through with an eye care provider if deemed appropriate. Diabetic eye exam completion rate was significantly higher (100%, 95%CI: 95.5%, 100%) in the intervention group (n = 81) than the control group (n = 83) (22%, 95%CI: 14.2%, 32.4%)(p < 0.001). In the intervention arm, 25/81 participants had an abnormal result, of whom 64% (16/25) completed follow-through with an eye care provider, compared to 22% in the control arm (p < 0.001). Autonomous AI increases diabetic eye exam completion rates in youth with diabetes.

Quick model-based viscoelastic clot strength predictions from blood protein concentrations for cybermedical coagulation control

Cybermedical systems that regulate patient clotting in real time with personalized blood product delivery will improve treatment outcomes. These systems will harness popular viscoelastic assays of clot strength such as thromboelastography (TEG), which help evaluate coagulation status in numerous conditions: major surgery (e.g., heart, vascular, hip fracture, and trauma); liver cirrhosis and transplants; COVID-19; ICU stays; sepsis; obstetrics; diabetes; and coagulopathies like hemophilia. But these measurements are time-consuming, and thus impractical for urgent care and automated coagulation control. Because protein concentrations in a blood sample can be measured in about five minutes, we develop personalized, phenomenological, quick, control-oriented models that predict TEG curve outputs from input blood protein concentrations, to facilitate treatment decisions based on TEG curves. Here, we accurately predict, experimentally validate, and mechanistically justify curves and parameters for common TEG assays (Functional Fibrinogen, Citrated Native, Platelet Mapping, and Rapid TEG), and verify results with trauma patient clotting data.

Serious Adverse Events and Laboratory Monitoring Regimens for Outpatient Parenteral Antimicrobial Therapy With Cefazolin and Ceftriaxone

The optimal laboratory monitoring frequency for outpatient parenteral antimicrobial therapy-related adverse events (OPAT-AEs) during cefazolin and ceftriaxone therapy is not well defined. We identified 2.7 OPAT-AEs per 1000 sets of weekly laboratory tests in this population, suggesting that less intensive laboratory monitoring may be safe and reasonable.

High prevalence group testing in epidemiology with geometrically inspired algorithms

Demand for mass surveillance during peak times of the SARS-CoV-2 pandemic caused high workload for clinical laboratories. Efficient and cost conserving testing designs by means of group testing can substantially reduce resources during possible future emergency situations. The novel hypercube algorithm proposed by Mutesa et al. 2021 published in Nature provides methodological proof of concept and points out the applicability to epidemiological testing. In this work, the algorithm is explored and expanded for settings with high group prevalence. Numerical studies investigate the limits of the adapted hypercube methodology, allowing to optimize pooling designs for specific requirements (i.e. number of samples and group prevalence). Hyperparameter optimization is performed to maximize test-reduction. Standard deviation is examined to investigate resilience and precision. Moreover, empirical validation was performed by elaborately pooling SARS-CoV-2 virus samples according to numerically optimized pooling designs. Laboratory experiments with SARS-CoV-2 sample groups, ranging from 50 to 200 items, characterized by group prevalence up to 10%, are successfully processed and analysed. Test-reductions from 50 to 72.5% were achieved in the experimental setups when compared to individual testing. Higher theoretical test-reduction is possible, depending on the number of samples and the group prevalence, indicated by simulation results.

Diagnostic accuracy of point-of-care ultrasound with artificial intelligence-assisted assessment of left ventricular ejection fraction

Focused cardiac ultrasound (FoCUS) is becoming standard practice in a wide spectrum of clinical settings. There is limited data evaluating the real-world use of FoCUS with artificial intelligence (AI). Our objective was to determine the accuracy of FoCUS AI-assisted left ventricular ejection fraction (LVEF) assessment and compare its accuracy between novice and experienced users. In this prospective, multicentre study, participants requiring a transthoracic echocardiogram (TTE) were recruited to have a FoCUS done by a novice or experienced user. The AI-assisted device calculated LVEF at the bedside, which was subsequently compared to TTE. 449 participants were enrolled with 424 studies included in the final analysis. The overall intraclass coefficient was 0.904, and 0.921 in the novice (n = 208) and 0.845 in the experienced (n = 216) cohorts. There was a significant bias of 0.73% towards TTE (p = 0.005) with a level of agreement of 11.2%. Categorical grading of LVEF severity had excellent agreement to TTE (weighted kappa = 0.83). The area under the curve (AUC) was 0.98 for identifying an abnormal LVEF (<50%) with a sensitivity of 92.8%, specificity of 92.3%, negative predictive value (NPV) of 0.97 and a positive predictive value (PPV) of 0.83. In identifying severe dysfunction (<30%) the AUC was 0.99 with a sensitivity of 78.1%, specificity of 98.0%, NPV of 0.98 and PPV of 0.76. Here we report that FoCUS AI-assisted LVEF assessments provide highly reproducible LVEF estimations in comparison to formal TTE. This finding was consistent among senior and novice echocardiographers suggesting applicability in a variety of clinical settings.

The contribution of human conflict to the development of antimicrobial resistance

Pallet et al. discuss the impact of human conflict on development of antimicrobial resistance. They overview approaches to limit the spread of antimicrobial resistance, using the ongoing conflict in Ukraine as an example of the challenges and opportunities.

Theoretical analysis of immunochromatographic assay and consideration of its operating parameters for efficient designing of high-sensitivity cardiac troponin I (hs-cTnI) detection

Troponin is the American College of Cardiology and American Heart Association preferred biomarker for diagnosing acute myocardial infarction (MI). We provide a modeling framework for high sensitivity cardiac Troponin I (hs-cTnI) detection in chromatographic immunoassays (flow displacement mode) with an analytical limit of detection, i.e., LOD < 10 ng/L. We show that each of the various control parameters exert a significant influence over the design requirements to reach the desired LOD. Additionally, the design implications in a multiplexed fluidic network, as in the case of Simple Plex™ Ella instrument, are significantly affected by the choice of the number of channels or partitions in the network. We also provide an upgrade on the existing LOD equation to evaluate the necessary minimum volume to detect a particular concentration by considering the effects of stochastics and directly incorporating the target number of copies in each of the partitions in case of multiplexed networks. Even though a special case of cTnI has been considered in this study, the model and analysis are analyte agnostic and may be applied to a wide class of chromatographic immunoassays. We believe that this contribution will lead to more efficient designing of the immunochromatographic assays.

Implementation of large-scale pooled testing to increase rapid molecular diagnostic test coverage for tuberculosis: a retrospective evaluation

In 2021, only 6.4 million of the 10.6 million people with tuberculosis (TB) were diagnosed and treated for the disease. Although the World Health Organization recommends initial diagnostic testing using a rapid sensitive molecular assay, only 38% of people diagnosed with TB benefited from these, due to barriers including the high cost of available assays. Pooled testing has been used as an approach to increase testing efficiency in many resource-constrained situations, such as the COVID-19 pandemic, but it has not yet been widely adopted for TB diagnostic testing. Here we report a retrospective analysis of routine pooled testing of 10,117 sputum specimens using the Xpert MTB/RIF and Xpert MTB/RIF Ultra assays that was performed from July 2020 to February 2022. Pooled testing saved 48% of assays and enabled rapid molecular testing for 4156 additional people as compared to individual testing, with 6.6% of specimens positive for TB. From an in silico analysis, the positive percent agreement of pooled testing in pools of 3 as compared with individual testing for the Xpert MTB/RIF Ultra assay was estimated as 99.4% (95% CI, 96.6% to 100%). These results support the scale-up of pooled testing for efficient TB diagnosis.

Metagenomic sequencing of post-mortem tissue samples for the identification of pathogens associated with neonatal deaths

Postmortem minimally invasive tissue sampling together with the detailed review of clinical records has been shown to be highly successful in determining the cause of neonatal deaths. However, conventional tests including traditional culture methods and nucleic acid amplification tests have periodically proven to be insufficient to detect the causative agent in the infectious deaths. In this study, metagenomic next generation sequencing was used to explore for putative pathogens associated with neonatal deaths in post-mortem blood and lung tissue samples, in Soweto, South Africa. Here we show that the metagenomic sequencing results corroborate the findings using conventional methods of culture and nucleic acid amplifications tests on post-mortem samples in detecting the pathogens attributed in the causal pathway of death in 90% (18/20) of the decedents. Furthermore, metagenomic sequencing detected a putative pathogen, including Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, and Serratia marcescens, in a further nine of 11 (81%) cases where no causative pathogen was identified. The antimicrobial susceptibility profile was also determined by the metagenomic sequencing for all pathogens with numerous multi drug resistant organism identified. In conclusion, metagenomic sequencing is able to successfully identify pathogens contributing to infection associated deaths on postmortem blood and tissue samples.

Data treatment methods for real-time colorimetric loop-mediated isothermal amplification reactions

With the SARS-CoV-2 pandemic and the need for affordable and rapid mass testing, colorimetric isothermal amplification reactions such as Loop-Mediated Isothermal Amplification (LAMP) are quickly rising in importance. The technique generates data that is similar to quantitative Polymerase Chain Reaction (qPCR), but instead of an endpoint color visualization, it is possible to construct a signal over a time curve. As the number of works using time-course analysis of isothermal reactions increases, there is a need to analyze data and standardize their related treatments quantitatively. Here, we take a step forward toward this goal by evaluating different available data treatments (curve models) for amplification curves, which allows for a cycle threshold-like parameter extraction. In this study, we uncover evidence of a double sigmoid equation as the most adequate model to describe amplification data from our remote diagnostics system and discuss possibilities for similar setups. We also demonstrate the use of multimodal Gompertz regression models. Thus, this work provides advances toward standardized and unbiased data reporting of Reverse Transcription (RT) LAMP reactions, which may facilitate and quicken assay interpretation, potentially enabling the application of machine learning techniques for further optimization and classification.

A pipeline for the fully automated estimation of continuous reference intervals using real-world data

Reference intervals are essential for interpreting laboratory test results. Continuous reference intervals precisely capture physiological age-specific dynamics that occur throughout life, and thus have the potential to improve clinical decision-making. However, established approaches for estimating continuous reference intervals require samples from healthy individuals, and are therefore substantially restricted. Indirect methods operating on routine measurements enable the estimation of one-dimensional reference intervals, however, no automated approach exists that integrates the dependency on a continuous covariate like age. We propose an integrated pipeline for the fully automated estimation of continuous reference intervals expressed as a generalized additive model for location, scale and shape based on discrete model estimates using an indirect method (refineR). The results are free of subjective user-input, enable conversion of test results into z-scores and can be integrated into laboratory information systems. Comparison of our results to established and validated reference intervals from the CALIPER and PEDREF studies and manufacturers' package inserts shows good agreement of reference limits, indicating that the proposed pipeline generates high-quality results. In conclusion, the developed pipeline enables the generation of high-precision percentile charts and continuous reference intervals. It represents the first parameter-less and fully automated solution for the indirect estimation of continuous reference intervals.

Results of German external quality assessment schemes for SARS-CoV-2 antigen detection

The COVID-19 pandemic illustrated the important role of diagnostic tests, including lateral flow tests (LFTs), in identifying patients and their contacts to slow the spread of infections. INSTAND performed external quality assessments (EQA) for SARS-CoV-2 antigen detection with lyophilized and chemically inactivated cell culture supernatant of SARS-CoV-2 infected Vero cells. A pre-study demonstrated the suitability of the material. Participants reported qualitative and/or quantitative antigen results using either LFTs or automated immunoassays for five EQA samples per survey. 711 data sets were reported for LFT detection in three surveys in 2021. This evaluation focused on the analytical sensitivity of different LFTs and automated immunoassays. The inter-laboratory results showed at least 94% correct results for non-variant of concern (VOC) SARS-CoV-2 antigen detection for viral loads of ≥ 4.75 × 106 copies/mL and SARS-CoV-2 negative samples. Up to 85% had success for a non-VOC viral load of ~ 1.60 × 106 copies/mL. A viral load of ~ 1.42 × 107 copies/mL of the Delta VOC was reported positive in > 96% of results. A high specificity was found with almost 100% negative SARS-CoV-2 antigen results for HCoV 229E and HCoV NL63 positive samples. Quantitative results correlated with increasing SARS-CoV-2 viral load but showed a broad scatter. This study shows promising SARS-CoV-2 antigen test performance of the participating laboratories, but further investigations with the now predominant Omicron VOC are needed.

Pooled RNA-extraction-free testing of saliva for the detection of SARS-CoV-2

The key to limiting SARS-CoV-2 spread is to identify virus-infected individuals (both symptomatic and asymptomatic) and isolate them from the general population. Hence, routine weekly testing for SARS-CoV-2 in all asymptomatic (capturing both infected and non-infected) individuals is considered critical in situations where a large number of individuals co-congregate such as schools, prisons, aged care facilities and industrial workplaces. Such testing is hampered by operational issues such as cost, test availability, access to healthcare workers and throughput. We developed the SalivaDirect RT-qPCR assay to increase access to SARS-CoV-2 testing via a low-cost, streamlined protocol using self-collected saliva. To expand the single sample testing protocol, we explored multiple extraction-free pooled saliva testing workflows prior to testing with the SalivaDirect RT-qPCR assay. A pool size of five, with or without heat inactivation at 65 °C for 15 min prior to testing resulted in a positive agreement of 98% and 89%, respectively, and an increased Ct value shift of 1.37 and 1.99 as compared to individual testing of the positive clinical saliva specimens. Applying this shift in Ct value to 316 individual, sequentially collected, SARS-CoV-2 positive saliva specimen results reported from six clinical laboratories using the original SalivaDirect assay, 100% of the samples would have been detected (Ct value < 45) had they been tested in the 1:5 pool strategy. The availability of multiple pooled testing workflows for laboratories can increase test turnaround time, permitting results in a more actionable time frame while minimizing testing costs and changes to laboratory operational flow.

Performance evaluation of newly developed surrogate virus neutralization tests for detecting neutralizing antibodies against SARS-CoV-2

We evaluated newly developed surrogate virus neutralization tests (sVNT) for detecting neutralizing antibodies (NAbs) against the receptor binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). VERI-Q SARS-CoV-2 Neutralizing Antibody Detection ELISA Kit (MiCo BioMed, Gyeonggi-do, Republic of Korea, hereafter, "eCoV-CN") is an enzyme-linked immunosorbent assay-based sVNT, and VERI-Q SARS-CoV-2 Neutralizing Antibody Rapid Test Kit (MiCo BioMed, hereafter, "rCoV-RN") is a point-of-care lateral-flow immunochromatography test with auto-scanner. A total of 411 serum samples were evaluated. Both evaluations used a 50% plaque reduction neutralization test (PRNT₅₀) as the gold standard. Compared with PRNT₅₀, the eCoV-CN showed 98.7% positive percent agreement (PPA), 96.8% negative percent agreement (NPA), 97.4% total percent agreement (TPA), with kappa values of 0.942. The rCoV-RN showed 98.7% PPA, 97.4% NPA, 97.8% TPA, and kappa values of 0.951, comparing to PRNT₅₀. Neither assay indicated cross-reactivity for other pathogens, and the signal indexes were statistically significantly correlated to the PRNT₅₀ titer. The two evaluated sVNTs show comparable performances to the PRNT₅₀ with the advantages of technical simplicity, speed, and do not require cell culture facilities.

Extraction-free clinical detection of SARS-CoV-2 virus from saline gargle samples using Hamilton STARlet liquid handler

As part of the COVID-19 pandemic, clinical laboratories have been faced with massive increases in testing, resulting in sample collection systems, reagent, and staff shortages. We utilized self-collected saline gargle samples to optimize high throughput SARS-CoV-2 multiplex polymerase chain reaction (PCR) testing in order to minimize cost and technologist time. This was achieved through elimination of nucleic acid extraction and automation of sample handling on a widely available robotic liquid handler, Hamilton STARlet. A customized barcode scanning script for reading the sample ID by the Hamilton STARlet's software system was developed to allow primary tube sampling. Use of pre-frozen SARS-CoV-2 assay reaction mixtures reduced assay setup time. In both validation and live testing, the assay produced no false positive or false negative results. Of the 1060 samples tested during validation, 3.6% (39/1060) of samples required retesting as they were either single gene positive, had internal control failure or liquid aspiration error. Although the overall turnaround time was only slightly faster in the automated workflow (185 min vs 200 min), there was a 76% reduction in hands-on time, potentially reducing staff fatigue and burnout. This described process from sample self-collection to automated direct PCR testing significantly reduces the total burden on healthcare systems in terms of human resources and reagent requirements.

Smartphone-based platforms implementing microfluidic detection with image-based artificial intelligence

The frequent outbreak of global infectious diseases has prompted the development of rapid and effective diagnostic tools for the early screening of potential patients in point-of-care testing scenarios. With advances in mobile computing power and microfluidic technology, the smartphone-based mobile health platform has drawn significant attention from researchers developing point-of-care testing devices that integrate microfluidic optical detection with artificial intelligence analysis. In this article, we summarize recent progress in these mobile health platforms, including the aspects of microfluidic chips, imaging modalities, supporting components, and the development of software algorithms. We document the application of mobile health platforms in terms of the detection objects, including molecules, viruses, cells, and parasites. Finally, we discuss the prospects for future development of mobile health platforms.

Serum lactate monitoring may help to predict neurological function impairment caused by acute metabolism crisis

To investigate the predictive value of serum lactate on neurological function impairment and the possible etiology. In this retrospective study, all the adult patients admitted to ICU more than 24 h after general anesthesia elective neurosurgery from January 2018 to January 2019 were recruited. The data of the serum lactate every 8 h during the 24 h of ICU admission were acquired and analyzed. 169 patients were included in the outcomes analysis. The average serum lactate after ICU admission was 3.7(3.4-4.1) mmol/L, higher than normal, and serum lactate elevated commonly after neurosurgery. The serum lactate at ICU admission (lactate_serum0h) was not correlated with the outcomes, whereas the predictive value increased as the monitoring time was extended. The result indicated that lactate_serum8h, the lactate_serum16h, and the lactate_serum24h were correlated with the primary outcome (difference of GCS scores before the surgery and after 24 h of ICU admission (ΔGCS_24h) (p < 0.05). The lactate_serum16h and the lactate_serum 24 h were correlated with all the outcomes except for the hospital LOS. The ROC curve suggested that the lactate_serum24h achieved the best predictive value. Patients with serum lactate non-recovered trend after 24 h of ICU stay had decreased GCS scores and vice versa, as indicated by the graph of the dynamic changes in the serum lactate. The predictive value of the serum glucose/serum lactate ratio at ICU admission (G/L_serum) was analyzed, and the result indicated that it was correlated with the ΔGCS_24h (p < 0.05), the G/L_serum can predict neurological impairment earlier. Dynamic serum lactate monitoring and the G/L_serum at ICU admission have predict value on neurological function impairment after neurosurgery which might be attributed to ACMC.

Semi-automated water sampling module for repeated sampling and concentration of Bacillus cereus group spores

Monitoring the presence of pathogenic Bacillus spores is important for industrial applications, as well as necessary for ensuring human health. Bacillus thuringiensis is used as a biopesticide against several insect pests. Bacillus cereus spores are a significant cause of food poisoning, and Bacillus anthracis is a recognized biosecurity threat. Laboratory-based methods, such as polymerase chain reaction, enzyme-linked immunosorbent assay, or matrix-assisted laser desorption ionization spectroscopy provide sensitive detection of bacteria and spores, but the application of those methods for quasi-continuous environmental monitoring presents a significant challenge requiring frequent human intervention. To address this challenge, we developed a workstation for quasi-autonomous monitoring of water reservoirs for the presence of bacteria and spores, and designed and validated the functionality of a microprocessor-controlled module capable of repetitive collection and pre-concentration of spores in liquid samples tested with fiberglass (FG), polyether sulfone and polyvinylidene fluoride filters. The best results were obtained with FG filters delivering a 20× concentration of B. thuringiensis and B. cereus spores from saline suspensions. The successful 20× pre-concentration of Bacillus spores demonstrated with FG filters could be repeated up to 3 times when bleach decontamination is applied between filtrations. Taken together, our results demonstrate an attractive instrument suitable for semi-automated, quasi-continuous sampling and pre-processing of water samples for biosensing of bacterial spores originating from a complex environment.

Differences in motor response to stability perturbations limit fall-resisting skill transfer

This study investigated transfer of improvements in stability recovery performance to novel perturbations. Thirty adults (20-53 yr) were assigned equally to three treadmill walking groups: groups exposed to eight trip perturbations of either low or high magnitude and a third control group that walked unperturbed. Following treadmill walking, participants were exposed to stability loss from a forward-inclined position (lean-and-release) and an overground trip. Lower limb joint kinematics for the swing phase of recovery steps was compared for the three tasks using statistical parametric mapping and recovery performance was analysed by margin of stability and base of support. The perturbation groups improved stability (greater margin of stability) over the eight gait perturbations. There was no group effect for stability recovery in lean-and-release. For the overground trip, both perturbation groups showed similar enhanced stability recovery (margin of stability and base of support) compared to controls. Differences in joint angle kinematics between treadmill-perturbation and lean-and-release were more prolonged and greater than between the two gait perturbation tasks. This study indicates that: (i) practising stability control enhances human resilience to novel perturbations; (ii) enhancement is not necessarily dependent on perturbation magnitude; (iii) differences in motor response patterns between tasks may limit transfer.

Label-free testing strategy to evaluate packed red blood cell quality before transfusion to leukemia patients

Patients worldwide require therapeutic transfusions of packed red blood cells (pRBCs), which is applied to the high-risk patients who need periodic transfusions due to leukemia, lymphoma, myeloma and other blood diseases or disorders. Contrary to the general hospital population where the transfusions are carried out mainly for healthy trauma patients, in case of high-risk patients the proper quality of pRBCs is crucial. This leads to an increased demand for efficient technology providing information on the pRBCs alterations deteriorating their quality. Here we present the design of an innovative, label-free, noninvasive, rapid Raman spectroscopy-based method for pRBCs quality evaluation, starting with the description of sample measurement and data analysis, through correlation of spectroscopic results with reference techniques' outcomes, and finishing with methodology verification and its application in clinical conditions. We have shown that Raman spectra collected from the pRBCs supernatant mixture with a proper chemometric analysis conducted for a minimum one ratio of integral intensities of the chosen Raman marker bands within the spectrum allow evaluation of the pRBC quality in a rapid, noninvasive, and free-label manner, without unsealing the pRBCs bag. Subsequently, spectroscopic data were compared with predefined reference values, either from pRBCs expiration or those defining the pRBCs quality, allowing to assess their utility for transfusion to patients with acute myeloid leukemia (AML) and lymphoblastic leukemia (ALL).

Prothrombotic state, endothelial injury, and echocardiographic changes in non-active sarcoidosis patients

Sarcoidosis is a multisystem inflammatory granulomatous disease of unknown cause that most commonly affects lungs and lymph nodes, with frequent yet asymptomatic cardiac involvement. The epidemiologically associated cardiovascular risk suggests an underlying prothrombotic state and endothelial dysfunction, currently understudied in the available literature. Therefore, we aimed to investigate prothrombotic plasma properties together with selected echocardiographic and laboratory biomarkers of cardiovascular injury in that disease. N = 53 patients with pulmonary sarcoidosis in clinical remission and N = 66 matched controls were assessed for inflammatory and endothelial injury biomarkers, plasma thrombin generation profile, and echocardiographic and lung function parameters. Sarcoidosis cases had impaired systolic and diastolic left ventricular function, higher concentrations of inflammatory markers, D-dimer and factor VIII activity compared to the controls. The coexistence of extrapulmonary disease was associated with elevated circulating vascular cell adhesion molecule 1, while cases with hypercalcemia had higher thrombomodulin concentration. Sarcoidosis was characterized by the unfavorably altered thrombin generation profile, reflected by the 16% higher endogenous thrombin potential (ETP), 24% increased peak thrombin concentration, and 12% shorter time to thrombin peak in comparison to the control group. ETP was higher in cases with proxies of pulmonary restriction, extrapulmonary-extracutaneous manifestation, and need for corticosteroids use. Despite the clinical remission, sarcoidosis is related to prothrombotic plasma properties and signs of endothelial injury, likely contributing to the higher risk of cardiovascular events. In addition, subclinical cardiac involvement may play an additional role, although further clinical and experimental studies are needed to verify these findings.

Rapid pathogen identification and phenotypic antimicrobial susceptibility directly from urine specimens

Implementing effective antimicrobial therapy close to the onset of infection lowers morbidity and mortality and attenuates the spread of antimicrobial resistance. Current antimicrobial susceptibility testing (AST) methods, however, require several days to determine optimal therapies. We present technology and an automated platform that identify (ID) Urinary Tract Infection pathogens in 45 min and provide phenotypic AST results in less than 5 h from urine specimens without colony isolation. The ID and AST tests count cells fluorescently labeled with specific rRNA probes using non-magnified digital imaging. The ID test detected five pathogens at ≤ 7,000 CFU/mL and had a linear range of ~ 4 orders of magnitude. For contrived specimens, AST tests gave 93.1% categorical agreement with 1.3% Very Major Errors (VME), 0.3% Major Errors (ME), and 6.3% minor Errors (mE) compared to the broth microdilution (BMD) reference method. For clinical specimens, the ID test had 98.6% agreement and the AST test had 92.3% categorical agreement with 4.2% mE, 3.4% ME and 4.0% VME compared to BMD. Data presented demonstrates that direct-from-specimen AST tests can accurately determine antimicrobial susceptibility/resistance for each pathogen in a specimen containing two pathogens. The method is robust to urine matrix effects and off-target commensal and contaminating bacteria.

Singleplex, multiplex and pooled sample real-time RT-PCR assays for detection of SARS-CoV-2 in an occupational medicine setting

For workplaces which cannot operate as telework or remotely, there is a critical need for routine occupational SARS-CoV-2 diagnostic testing. Although diagnostic tests including the CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel (CDC Diagnostic Panel) (EUA200001) were made available early in the pandemic, resource scarcity and high demand for reagents and equipment necessitated priority of symptomatic patients. There is a clearly defined need for flexible testing methodologies and strategies with rapid turnaround of results for (1) symptomatic, (2) asymptomatic with high-risk exposures and (3) asymptomatic populations without preexisting conditions for routine screening to address the needs of an on-site work force. We developed a distinct SARS-CoV-2 diagnostic assay based on the original CDC Diagnostic Panel (EUA200001), yet, with minimum overlap for currently employed reagents to eliminate direct competition for limited resources. As the pandemic progressed with testing loads increasing, we modified the assay to include 5-sample pooling and amplicon target multiplexing. Analytical sensitivity of the pooled and multiplexed assays was rigorously tested with contrived positive samples in realistic patient backgrounds. Assay performance was determined with clinical samples previously assessed with an FDA authorized assay. Throughout the pandemic we successfully tested symptomatic, known contact and travelers within our occupational population with a ~ 24-48-h turnaround time to limit the spread of COVID-19 in the workplace. Our singleplex assay had a detection limit of 31.25 copies per reaction. The three-color multiplexed assay maintained similar sensitivity to the singleplex assay, while tripling the throughput. The pooling assay further increased the throughput to five-fold the singleplex assay, albeit with a subtle loss of sensitivity. We subsequently developed a hybrid 'multiplex-pooled' strategy to testing to address the need for both rapid analysis of samples from personnel at high risk of COVID infection and routine screening. Herein, our SARS-CoV-2 assays specifically address the needs of occupational healthcare for both rapid analysis of personnel at high-risk of infection and routine screening that is essential for controlling COVID-19 disease transmission. In addition to SARS-CoV-2 and COVID-19, this work demonstrates successful flexible assays developments and deployments with implications for emerging highly transmissible diseases and future pandemics.

Clinical evaluation of a new rapid immunochromatographic test for detection of Bordetella pertussis antigen

A more rapid and less complicated test to diagnose pertussis is required in clinical settings. We need to detect Bordetella pertussis, which mainly causes pertussis, as early as possible, because pertussis is more likely to become severe in infants, and people around them can easily become a source of infection due to its strong infectivity. Nevertheless, methods that can detect B. pertussis rapidly and efficiently are lacking. Therefore, we developed a new immunochromatographic antigen kit (ICkit) for the early diagnosis of pertussis. The ICkit detects B. pertussis antigens in a nasopharyngeal swab without equipment and provides the result in about 15 min with a simple procedure. Additionally, a prospective study to evaluate the ICkit was conducted in 11 medical institutions, involving 195 cases with suspected pertussis. Compared with the real-time polymerase chain reaction (rPCR), the sensitivity and specificity of the ICkit were 86.4% (19/22) and 97.1% (168/173), respectively. The ICkit detected the antigen in both children and adults. Furthermore, the ICkit detected the antigen until the 25th day from the onset of cough, when rPCR detected the antigen. Thus, the ICkit demonstrated a high correlation with rPCR and would help diagnose pertussis more rapidly and efficiently.

Defining the area of mitoses counting in invasive breast cancer using whole slide image

Although counting mitoses is part of breast cancer grading, concordance studies showed low agreement. Refining the criteria for mitotic counting can improve concordance, particularly when using whole slide images (WSIs). This study aims to refine the methodology for optimal mitoses counting on WSI. Digital images of 595 hematoxylin and eosin stained sections were evaluated. Several morphological criteria were investigated and applied to define mitotic hotspots. Reproducibility, representativeness, time, and association with outcome were the criteria used to evaluate the best area size for mitoses counting. Three approaches for scoring mitoses on WSIs (single and multiple annotated rectangles and multiple digital high-power (×40) screen fields (HPSFs)) were evaluated. The relative increase in tumor cell density was the most significant and easiest parameter for identifying hotspots. Counting mitoses in 3 mm² area was the most representative regarding saturation and concordance levels. Counting in area <2 mm² resulted in a significant reduction in mitotic count (P = 0.02), whereas counting in area ≥4 mm² was time-consuming and did not add a significant rise in overall mitotic count (P = 0.08). Using multiple HPSF, following calibration, provided the most reliable, timesaving, and practical method for mitoses counting on WSI. This study provides evidence-based methodology for defining the area and methodology of visual mitoses counting using WSI. Visual mitoses scoring on WSI can be performed reliably by adjusting the number of monitor screens.

Limit of detection in different matrices of 19 commercially available rapid antigen tests for the detection of SARS-CoV-2

In the context of the coronavirus disease 2019 (COVID-19) pandemic there has been an increase of the use of antigen-detection rapid diagnostic tests (Ag-RDT). The performance of Ag-RDT vary greatly between manufacturers and evaluating their analytical limit of detection (LOD) has become high priority. Here we describe a manufacturer-independent evaluation of the LOD of 19 marketed Ag-RDT using live SARS-CoV-2 spiked in different matrices: direct culture supernatant, a dry swab, and a swab in Amies. Additionally, the LOD using dry swab was investigated after 7 days' storage at - 80 °C of the SARS-CoV-2 serial dilutions. An LOD of ≈ 5.0 × 102 pfu/ml (1.0 × 106 genome copies/ml) in culture media is defined as acceptable by the World Health Organization. Fourteen of 19 Ag-RDTs (ActiveXpress, Espline, Excalibur, Innova, Joysbio, Mologic, NowCheck, Orient, PanBio, RespiStrip, Roche, Standard-F, Standard-Q and Sure-Status) exceeded this performance criteria using direct culture supernatant applied to the Ag-RDT. Six Ag-RDT were not compatible with Amies media and a decreased sensitivity of 2 to 20-fold was observed for eleven tests on the stored dilutions at - 80 °C for 7 days. Here, we provide analytical sensitivity data to guide appropriate test and sample type selection for use and for future Ag-RDT evaluations.

Performance characteristics and costs of serological tests for brucellosis in a pastoralist community of northern Tanzania

The control of brucellosis across sub-Saharan Africa is hampered by the lack of standardized testing and the use of tests with poor performance. This study evaluated the performance and costs of serological assays for human brucellosis in a pastoralist community in northern Tanzania. Serum collected from 218 febrile hospital patients was used to evaluate the performance of seven index tests, selected based on international recommendation or current use. We evaluated the Rose Bengal test (RBT) using two protocols, four commercial agglutination tests and a competitive enzyme-linked immunosorbent assay (cELISA). The sensitivity, specificity, positive predictive value, negative predictive value, Youden's index, diagnostic accuracy, and per-sample cost of each index test were estimated. The diagnostic accuracy estimates ranged from 95.9 to 97.7% for the RBT, 55.0 to 72.0% for the commercial plate tests, and 89.4% for the cELISA. The per-sample cost range was $0.69-$0.79 for the RBT, $1.03-$1.14 for the commercial plate tests, and $2.51 for the cELISA. The widely used commercial plate tests performed poorly and cost more than the RBT. These findings provide evidence for the public health value of discontinuing the use of commercial agglutination tests for human brucellosis in Tanzania.

Digital PCR for high sensitivity viral detection in false-negative SARS-CoV-2 patients

Patients requiring diagnostic testing for coronavirus disease 2019 (COVID-19) are routinely assessed by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) amplification of Sars-CoV-2 virus RNA extracted from oro/nasopharyngeal swabs. Despite the good specificity of the assays certified for SARS-CoV-2 molecular detection, and a theoretical sensitivity of few viral gene copies per reaction, a relatively high rate of false negatives continues to be reported. This is an important challenge in the management of patients on hospital admission and for correct monitoring of the infectivity after the acute phase. In the present report, we show that the use of digital PCR, a high sensitivity method to detect low amplicon numbers, allowed us to correctly detecting infection in swab material in a significant number of false negatives. We show that the implementation of digital PCR methods in the diagnostic assessment of COVID-19 could resolve, at least in part, this timely issue.

Standardization of ELISA protocols for serosurveys of the SARS-CoV-2 pandemic using clinical and at-home blood sampling

The extent of SARS-CoV-2 infection throughout the United States population is currently unknown. High quality serology is key to avoiding medically costly diagnostic errors, as well as to assuring properly informed public health decisions. Here, we present an optimized ELISA-based serology protocol, from antigen production to data analyses, that helps define thresholds for IgG and IgM seropositivity with high specificities. Validation of this protocol is performed using traditionally collected serum as well as dried blood on mail-in blood sampling kits. Archival (pre-2019) samples are used as negative controls, and convalescent, PCR-diagnosed COVID-19 patient samples serve as positive controls. Using this protocol, minimal cross-reactivity is observed for the spike proteins of MERS, SARS1, OC43 and HKU1 viruses, and no cross reactivity is observed with anti-influenza A H1N1 HAI. Our protocol may thus help provide standardized, population-based data on the extent of SARS-CoV-2 seropositivity, immunity and infection.

Non-invasive carbon dioxide monitoring in neonates: methods, benefits, and pitfalls

Wide fluctuations in partial pressure of carbon dioxide (PaCO₂) can potentially be associated with neurological and lung injury in neonates. Blood gas measurement is the gold standard for assessing gas exchange but is intermittent, invasive, and contributes to iatrogenic blood loss. Non-invasive carbon dioxide (CO₂) monitoring has become ubiquitous in anesthesia and critical care and is being increasingly used in neonates. Two common methods of non-invasive CO₂ monitoring are end-tidal and transcutaneous. A colorimetric CO₂ detector (a modified end-tidal CO₂ detector) is recommended by the International Liaison Committee on Resuscitation (ILCOR) and the American Academy of Pediatrics to confirm endotracheal tube placement. Continuous CO₂ monitoring is helpful in trending PaCO₂ in critically ill neonates on respiratory support and can potentially lead to early detection and minimization of fluctuations in PaCO₂. This review includes a description of the various types of CO₂ monitoring and their applications, benefits, and limitations in neonates.

Automated identification of leukocyte subsets improves standardization of database-guided expert-supervised diagnostic orientation in acute leukemia: a EuroFlow study

Precise classification of acute leukemia (AL) is crucial for adequate treatment. EuroFlow has previously designed an AL orientation tube (ALOT) to guide toward the relevant classification panel and final diagnosis. In this study, we designed and validated an algorithm for automated (database-supported) gating and identification (AGI tool) of cell subsets within samples stained with ALOT. A reference database of normal peripheral blood (PB, n = 41) and bone marrow (BM; n = 45) samples analyzed with the ALOT was constructed, and served as a reference for the AGI tool to automatically identify normal cells. Populations not unequivocally identified as normal cells were labeled as checks and were classified by an expert. Additional normal BM (n = 25) and PB (n = 43) and leukemic samples (n = 109), analyzed in parallel by experts and the AGI tool, were used to evaluate the AGI tool. Analysis of normal PB and BM samples showed low percentages of checks (<3% in PB, <10% in BM), with variations between different laboratories. Manual analysis and AGI analysis of normal and leukemic samples showed high levels of correlation between cell numbers (r² > 0.95 for all cell types in PB and r² > 0.75 in BM) and resulted in highly concordant classification of leukemic cells by our previously published automated database-guided expert-supervised orientation tool for immunophenotypic diagnosis and classification of acute leukemia (Compass tool). Similar data were obtained using alternative, commercially available tubes, confirming the robustness of the developed tools. The AGI tool represents an innovative step in minimizing human intervention and requirements in expertise, toward a "sample-in and result-out" approach which may result in more objective and reproducible data analysis and diagnostics. The AGI tool may improve quality of immunophenotyping in individual laboratories, since high percentages of checks in normal samples are an alert on the quality of the internal procedures.

Massive and rapid COVID-19 testing is feasible by extraction-free SARS-CoV-2 RT-PCR

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is commonly diagnosed by reverse transcription polymerase chain reaction (RT-PCR) to detect viral RNA in patient samples, but RNA extraction constitutes a major bottleneck in current testing. Methodological simplification could increase diagnostic availability and efficiency, benefitting patient care and infection control. Here, we describe methods circumventing RNA extraction in COVID-19 testing by performing RT-PCR directly on heat-inactivated or lysed samples. Our data, including benchmarking using 597 clinical patient samples and a standardised diagnostic system, demonstrate that direct RT-PCR is viable option to extraction-based tests. Using controlled amounts of active SARS-CoV-2, we confirm effectiveness of heat inactivation by plaque assay and evaluate various generic buffers as transport medium for direct RT-PCR. Significant savings in time and cost are achieved through RNA-extraction-free protocols that are directly compatible with established PCR-based testing pipelines. This could aid expansion of COVID-19 testing.

Extract from used Xpert MTB/RIF Ultra cartridges is useful for accurate second-line drug-resistant tuberculosis diagnosis with minimal rpoB-amplicon cross-contamination risk

Xpert MTB/RIF Ultra (Ultra) detects Mycobacterium tuberculosis and rifampicin resistance. Follow-on drug susceptibility testing (DST) requires additional sputum. Extract from the diamond-shaped chamber of the cartridge (dCE) of Ultra's predecessor, Xpert MTB/RIF (Xpert), is useful for MTBDRsl-based DST but this is unexplored with Ultra. Furthermore, whether CE from non-diamond compartments is useful, the performance of FluoroType MTBDR (FT) on  CE, and rpoB cross-contamination risk associated with the extraction procedure are unknown. We tested MTBDRsl, MTBDRplus, and FT on CEs from chambers from cartridges (Ultra, Xpert) tested on bacilli dilution series. MTBDRsl on Ultra dCE on TB-positive sputa (n = 40) was also evaluated and, separately, rpoB amplicon cross-contamination risk . MTBDRsl on Ultra dCE from dilutions ≥103 CFU/ml (CTmin <25, >"low semi-quantitation") detected fluoroquinolone (FQ) and second-line injectable (SLID) susceptibility and resistance correctly (some SLIDs-indeterminate). At the same threshold (at which ~85% of Ultra-positives in our setting would be eligible), 35/35 (100%) FQ and 34/35 (97%) SLID results from Ultra dCE were concordant with sputa results. Tests on other chambers were unfeasible. No tubes open during 20 batched extractions had FT-detected rpoB cross-contamination. False-positive Ultra rpoB results was observed when dCE dilutions ≤10-3 were re-tested. MTBDRsl on Ultra dCE is concordant with isolate results. rpoB amplicon cross-contamination is unlikely. These data mitigate additional specimen collection for second-line DST and cross-contamination concerns.

Reality check of laboratory service effectiveness during pandemic (H1N1) 2009, Victoria, Australia

In Australia, the outbreak of pandemic (H1N1) 2009 began in Melbourne, Victoria; in the first 17 days, the Victorian Infectious Diseases Reference Laboratory detected 977 cases. Although the laboratory had a pandemic plan in place, a retrospective evaluation found 3 major variations from plan assumptions: 1) higher peak demand not limited by a case definition, 2) prolonged peak demand because containment attempts continued despite widespread influenza, and 3) unexpected influence of negative test results on public health actions. Although implementation of the plan was generally successful, the greatest challenges were limited availability of skilled staff and test reagents. Despite peak demand of 1,401 tests per day, results were provided within the usual 24 hours of specimen receipt; however, turnaround time seemed slower because of slow transport times (>3 days for 45% of specimens). Hence, effective laboratory capability might be enhanced by speeding transport of specimens and improving transmission of clinical data.

Adherence to laboratory test requests by patients with diabetes: the Diabetes Study of Northern California (DISTANCE)

OBJECTIVES

To estimate rates and predictors of clinical laboratory test completion by patients with diabetes after provider referral.

STUDY DESIGN

Prospective cohort study.

METHODS

Among 186,306 adult members with diabetes in Kaiser Permanente Northern California, we searched the electronic medical records (July 1, 2008, to June 30, 2009) of each patient for the first outpatient order to obtain the following laboratory tests commonly used to measure risk factor control or adverse effects of pharmacotherapy: levels of glycosylated hemoglobin, low density lipoprotein cholesterol, serum creatinine, urinary albumin, or creatine kinase (the latter only among persons using statins). We measured laboratory test attendance as completion of an order (including time to results) within 6 months of the referral date and looked for variations by subgroups.

RESULTS

Laboratory test attendance ranged from 86% for glycosylated hemoglobin level to 73% for serum creatinine level. Time to laboratory test attendance was a median of 7 to 11 days and a mean of 25 to 30 days. Laboratory test attendance was more likely for women and older patients or for orders after a face-to-face provider visit and was less likely for orders by a pharmacist. However, most variations (even by laboratory copayment) were small or not clinically substantive. In subanalyses, we observed no clinically significant variations by race/ethnicity, socioeconomic status, trust in provider, or patient-provider communication and found no association with depressive symptoms, health literacy, or English fluency.

CONCLUSION

The fact that 1 in 7 patients did not complete laboratory tests within 6 months of the provider referral may help explain why healthcare services seem to fall short of optimal diabetes care.

Analytical and clinical performance of blood glucose monitors

BACKGROUND

The objective of this study was to understand the level of performance of blood glucose monitors as assessed in the published literature.

METHODS

Medline from January 2000 to October 2009 and reference lists of included articles were searched to identify eligible studies. Key information was abstracted from eligible studies: blood glucose meters tested, blood sample, meter operators, setting, sample of people (number, diabetes type, age, sex, and race), duration of diabetes, years using a glucose meter, insulin use, recommendations followed, performance evaluation measures, and specific factors affecting the accuracy evaluation of blood glucose monitors.

RESULTS

Thirty-one articles were included in this review. Articles were categorized as review articles of blood glucose accuracy (6 articles), original studies that reported the performance of blood glucose meters in laboratory settings (14 articles) or clinical settings (9 articles), and simulation studies (2 articles). A variety of performance evaluation measures were used in the studies. The authors did not identify any studies that demonstrated a difference in clinical outcomes. Examples of analytical tools used in the description of accuracy (e.g., correlation coefficient, linear regression equations, and International Organization for Standardization standards) and how these traditional measures can complicate the achievement of target blood glucose levels for the patient were presented. The benefits of using error grid analysis to quantify the clinical accuracy of patient-determined blood glucose values were discussed.

CONCLUSIONS

When examining blood glucose monitor performance in the real world, it is important to consider if an improvement in analytical accuracy would lead to improved clinical outcomes for patients. There are several examples of how analytical tools used in the description of self-monitoring of blood glucose accuracy could be irrelevant to treatment decisions.

Evaluation of a dried blood spot HIV-1 RNA program for early infant diagnosis and viral load monitoring at rural and remote healthcare facilities

OBJECTIVE

To assess technical and operational performance of a dried blood spot (DBS)-based HIV-1 RNA service for remote healthcare facilities in a low-income country.

DESIGN

A method comparison and operational evaluation of DBS RNA against conventional tests for early infant diagnosis of HIV and HIV RNA quantitation under field conditions in Tanzania.

METHODS

DBSs were prepared and plasma was frozen at -80 degrees C. DBSs were mailed and plasma couriered to a central laboratory for testing using the Abbott m2000 system. Infant diagnosis DBSs were also tested for HIV-1 DNA by ROCHE COBAS AmpliPrep/COBAS TaqMan System. Results of DBS RNA were compared with conventional tests; program performance was described.

RESULTS

Among 176 infant diagnosis participants, using a threshold of at least 1000 copies/ml, sensitivity and specificity of DBS versus plasma RNA were 1.00 and 0.99, and of DBS RNA versus DBS DNA were 0.97 and 1.00. Among 137 viral load monitoring participants, when plasma and DBS RNA were compared, r value was 0.9709; r value was 0.9675 for at least 5000 copies/ml but was 0.7301 for less than 5000 copies/ml. The highest plasma RNA value at which DBS RNA was not detected was 2084 copies/ml. Median (range) turnaround time from sample collection to result receipt at sites was 23 (4-69) days. The Tanzania mail service successfully transmitted all DBS and results between sites and the central laboratory.

CONCLUSION

Under program conditions in Tanzania, DBS provided HIV-1 RNA results comparable to conventional methods to remote healthcare facilities. DBS RNA testing is an alternative to liquid plasma for HIV-1 RNA services in remote areas.

Influence of watchful waiting on satisfaction and anxiety among patients seeking care for unexplained complaints

PURPOSE

We undertook a study to determine whether test-ordering strategy and other consultation-related factors influence satisfaction with and anxiety after a consultation among patients seeking care for unexplained complaints.

METHODS

A cluster-randomized clinical trial was conducted in family medicine practices in the Netherlands. Participants were 498 patients with unexplained complaints seen by 63 primary care physicians. Physicians either immediately ordered a blood test for patients or followed a 4-week watchful waiting approach. Physicians and patients completed questionnaires asking about their characteristics, satisfaction with care, and anxiety, and aspects of the consultation. The main outcomes were patient satisfaction and anxiety. Data were analyzed by multilevel logistic regression analysis.

RESULTS

Patients were generally satisfied with their consultation and had moderately low anxiety afterward (mean scores on 11-point scales, 7.3 and 3.1, respectively), with no difference between the immediate testing and watchful waiting groups (chi(2) = 2.4 and 0.3, respectively). The factors associated with higher odds of satisfaction were mainly related to physician-patient communication: patients' satisfaction with their physician generally, feeling taken seriously, and knowing the seriousness of complaints afterward; physicians' discussing testing and not considering complaints bearable; and older physician age. The same was true for factors associated with higher odds of anxiety: patients expecting testing or referral, patients not knowing the seriousness of their complaints afterward, and physicians not seeing a cause for alarm.

CONCLUSIONS

Test-ordering strategy does not influence patients' satisfaction with and anxiety after a consultation. Instead, specific aspects of physician-patient communication are important. Apparently, primary care physicians underestimate how much they can contribute to the well-being of their patients by discussing their worries.