Evaluating an extraction-free sample preparation method for multiplex detection of SARS-Cov-2, influenza A/B, and RSV with implementation on a microfluidic chip

Following the relaxation of COVID-19 restrictions, other respiratory viruses such as influenza and respiratory syncytial virus (RSV), whose transmission were decreased due to COVID-19 precautions, are rising again. Because of similar clinical features and reported co-infections, multiplex detection of SARS-CoV-2, influenza A/B, and RSV is required to use specific treatments. This study assessed an extraction-free sample preparation (heat treatment at 95°C for 3 minutes) for multiplex detection using rRT-PCR. Despite an observed Ct-delay (∆Ct) averageing 1.26 compared to the standard method, an acceptable total sensitivity of 92 % and a negative predictive value (NPV) of 96 % were obtained. Moreover, Implementation on a microfluidic chip demonstrated efficiency, maintaining an excellent correlation (R2=0.983) with the standard method. Combining this extraction-free procedure with rRT-PCR on a microfluidic chip seems promising, because it simplifies the design and reduces the cost and complexity of the integrated assay for multiplex detection of SARS-CoV-2, influenza A/B, and RSV.

Adoption of C-reactive protein rapid tests for the management of acute childhood infections in hospitals in the Netherlands and England: a comparative health systems analysis

BACKGROUND

The adoption of C-reactive protein point-of-care tests (CRP POCTs) in hospitals varies across Europe. We aimed to understand the factors that contribute to different levels of adoption of CRP POCTs for the management of acute childhood infections in two countries.

METHODS

Comparative qualitative analysis of the implementation of CRP POCTs in the Netherlands and England. The study was informed by the non-adoption, abandonment, spread, scale-up, and sustainability (NASSS) framework. Data were collected through document analysis and qualitative interviews with stakeholders. Documents were identified by a scoping literature review, search of websites, and through the stakeholders. Stakeholders were sampled purposively initially, and then by snowballing. Data were analysed thematically.

RESULTS

Forty-one documents resulted from the search and 46 interviews were conducted. Most hospital healthcare workers in the Netherlands were familiar with CRP POCTs as the tests were widely used and trusted in primary care. Moreover, although diagnostics were funded through similar Diagnosis Related Group reimbursement mechanisms in both countries, the actual funding for each hospital was more constrained in England. Compared to primary care, laboratory-based CRP tests were usually available in hospitals and their use was encouraged in both countries because they were cheaper. However, CRP POCTs were perceived as useful in some hospitals of the two countries in which the laboratory could not provide CRP measures 24/7 or within a short timeframe, and/or in emergency departments where expediting patient care was important.

CONCLUSIONS

CRP POCTs are more available in hospitals in the Netherlands because of the greater familiarity of Dutch healthcare workers with the tests which are widely used in primary care in their country and because there are more funding constraints in England. However, most hospitals in the Netherlands and England have not adopted CRP POCTs because the alternative CRP measurements from the hospital laboratory are available in a few hours and at a lower cost.

The diagnostic Accuracy of Visual versus automated dipstick proteinuria testing in Pregnancy: A systematic review and Meta-Analysis

OBJECTIVE

To evaluate the diagnostic accuracy of point-of-care (POC) tests for detecting proteinuria in pregnant women.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE and EMBASE databases were searched from inception to 13 November 2020.

ELIGIBILITY CRITERIA AND DATA ANALYSIS

Included studies measured the sensitivity and specificity ofPOC proteinuria testing compared to laboratory reference standards (protein-creatinine ratio (PCR), 24-hour urine collection). Bivariate meta-analyses determined pooled sensitivity and specificity. Random-effects inverse-variance model determinedheterogeneity.

MAIN OUTCOME MEASURES

The primary outcome was overall sensitivity and specificity, stratified by method of POC testing and reference standard. Secondary outcomes were sensitivity and specificity within thesubgroupstest brand, reference standard, and hypertension status.

RESULTS

1078 studies were identified, 17 studies comprising 23 comparisons were included. The meta-analysis included 13 studies with 19 comparisons. Pooled sensitivity and specificity of visual dipsticks against PCR was 72 % (95 % CI: 56 % to 84 %) and 92 % (95 % CI: 76 % to 98 %), respectively. Pooled sensitivity and specificity of visual dipsticks against 24-hour collection was 69 % (55 % to 80 %) and 70 % (51 % to 84 %), respectively. Pooled sensitivity and specificity for automated readers against PCR was 73 % (53 % to 86 %) and 91 % (83 % to 95 %), respectively. Pooled sensitivity and specificity of automated readers against 24-hour collection was 65 % (42 % to 83 %) and 82 % (46 % to 96 %), respectively.

CONCLUSION

Visual dipsticks have comparable accuracy to automated readers, yet are notadequate as a rule-out test for proteinuria. Proteinuria POC testing maybe beneficial inantenatal care when repeatfollow-up tests are performed. PROSPERO Registration Number: CRD42021231914.

Changes in coagulation and temperature management in burn patients - A survey of burn centers in Switzerland, Austria and Germany

BACKGROUND

Severely burned patients suffer from both coagulopathy and hypothermia, with a lack of international consensus and appropriate treatment guidelines. This study examines recent developments and trends in coagulation and temperature management in European burn centers.

METHODS

A survey was sent to burn centers in Switzerland, Austria and Germany in 2016 and again in 2021. The analysis was performed using descriptive statistics, with categorical data reported in absolute numbers (n) and percentages (%) and numerical data reported as mean and standard deviation.

RESULTS

The rate of completed questionnaires was 84 % (16 of 19 questionnaires) in 2016 and 91 % (21 of 22 questionnaires) in 2021. The number of global coagulation tests performed has decreased over the observation period in favor of single factor determination and bed-side point-of-care coagulation tests. This has also led to increased administration of single factor concentrates in therapy. Although many centers had a defined treatment protocol for hypothermia in 2016, coverage increased such that in 2021 all centers surveyed had such a protocol. The body temperature was measured more consistently in 2021; thus, hypothermia was more actively sought, detected and treated.

CONCLUSION

A point-of-care guided, factor-based coagulation management and the maintenance of normothermia have gained importance in the care of burn patients in recent years.

Engineering Innovative Interfaces for Point-of-Care Diagnostics

The ongoing Coronavirus disease 2019 (COVID-19) pandemic illustrates the need for sensitive and reliable tools to diagnose and monitor diseases. Traditional diagnostic approaches rely on centralized laboratory tests that result in long wait times to results and reduce the number of tests that can be given. Point-of-care tests (POCTs) are a group of technologies that miniaturize clinical assays into portable form factors that can be run both in clinical areas --in place of traditional tests-- and outside of traditional clinical settings --to enable new testing paradigms. Hallmark examples of POCTs are the pregnancy test lateral flow assay and the blood glucose meter. Other uses for POCTs include diagnostic assays for diseases like COVID-19, HIV, and malaria but despite some successes, there are still unsolved challenges for fully translating these lower cost and more versatile solutions. To overcome these challenges, researchers have exploited innovations in colloid and interface science to develop various designs of POCTs for clinical applications. Herein, we provide a review of recent advancements in lateral flow assays, other paper based POCTs, protein microarray assays, microbead flow assays, and nucleic acid amplification assays. Features that are desirable to integrate into future POCTs, including simplified sample collection, end-to-end connectivity, and machine learning, are also discussed in this review.

Plasmonic optical fiber biosensor development for point-of-care detection of malondialdehyde as a biomarker of oxidative stress

Numerous pieces of evidence demonstrate that oxidative stress impairs biological functions, speeds up aging, and has a role in a variety of human diseases, including systemic and oral inflammatory disorders, and even cancer. Therefore, technologies providing accurate measures of oxidative stress indicators or biomarkers appear essential in the identification/prevention of such diseases, and in their management. Particularly advantageous is the employement of point-of-care tests based on affordable and small biochips since they can quickly process biological samples and deliver results near the point of care for a prompt therapeutic intervention. Malondialdehyde (MDA) is a key byproduct of oxidative reaction and has been identified as an effective marker of oxidative stress. Herein, we describe the detection of MDA in buffer and in a complex matrix such as saliva, using a plasmonic optical fiber device combined with a highly selective anti-MDA antibody. The experimental results highlight the excellent performance of the proposed biosensor, as well as its ability to provide a low-cost point-of-care test (PoC-T) to be used in real life situations. We demonstrated that a single saliva dilution step and a short incubation time are required for the accurate detection of low concentrations of total MDA (free and conjugated). As a proof-of-concept of future biomedical applications, the method has been tested to determine MDA concentration in saliva of a periodontitis patient compared to that of a healthy control. The obtained findings represent the basis for developing PoC-Ts to be employed in monitoring oral diseases like periodontitis, oral cancers or systemic oxidative-stress associated pathologies. Conclusively, our study puts the ground for an oxidative stress biosensor widely-applicable to different scenarios.

Adoption of C-reactive protein point-of-care tests for the management of acute childhood infections in primary care in the Netherlands and England: a comparative health systems analysis

BACKGROUND

The use of point of care (POC) tests varies across Europe, but research into what drives this variability is lacking. Focusing on CRP POC tests, we aimed to understand what factors contribute to high versus low adoption of the tests, and also to explore whether they are used in children.

METHODS

We used a comparative qualitative case study approach to explore the implementation of CRP POC tests in the Netherlands and England. These countries were selected because although they have similar primary healthcare systems, the availability of CRP POC tests in General Practices is very different, being very high in the former and rare in the latter. The study design and analysis were informed by the non-adoption, abandonment, spread, scale-up and sustainability (NASSS) framework. Data were collected through a review of documents and interviews with stakeholders. Documents were identified through a scoping literature review, search of websites, and stakeholder recommendation. Stakeholders were selected purposively initially, and then by snowballing. Data were analysed thematically.

RESULTS

Sixty-five documents were reviewed and 21 interviews were conducted. The difference in the availability of CRP POC tests is mainly because of differences at the wider national context level. In the two countries, early adopters of the tests advocated for their implementation through the generation of robust evidence and by engaging with all relevant stakeholders. This led to the inclusion of CRP POC tests in clinical guidelines in both countries. In the Netherlands, this mandated their reimbursement in accordance with Dutch regulations. Moreover, the prevailing better integration of health services enabled operational support from laboratories to GP practices. In England, the funding constraints of the National Health Service and the prioritization of alternative and less expensive antimicrobial stewardship interventions prevented the development of a reimbursement scheme. In addition, the lack of integration between health services limits the operational support to GP practices. In both countries, the availability of CRP POC tests for the management of children is a by-product of the test being available for adults. The tests are less used in children mainly because of concerns regarding their accuracy in this age-group.

CONCLUSIONS

The engagement of early adopters combined with a more favourable and receptive macro level environment, including the role of clinical guidelines and their developers in determining which interventions are reimbursed and the operational support from laboratories to GP practices, led to the greater adoption of the tests in the Netherlands. In both countries, CRP POC tests, when available, are less used less in children. Organisations considering introducing POC tests into primary care settings need to consider how their implementation fits into the wider health system context to ensure achievable plans.

Research on point-of-care tests in outpatient care in Germany: A scoping review and definition of relevant endpoints in evaluation studies

BACKGROUND

The fast turnaround time and user-friendliness of point-of-care tests (POCTs) offer a great potential to improve outpatient health care where clinical decisions have to be made during the physician-patient encounter and time resources are limited. The aim of this scoping review is to describe the extent and nature as well as gaps in German research activities on POCT in outpatient care. In addition, we define research endpoints that should be addressed in the comprehensive evaluation of POCTs targeted for outpatient care.

METHODS

We performed a scoping review with a systematic literature search in Medline (via PubMed), Scopus, Web of Science, Cochrane library and Google Scholar for German publications on POCT with relevance to German outpatient care published from January 2005 to November 2020.

RESULTS

Our literature search identified 2,200 unique records. After literature selection 117 articles were included in this scoping review. Just over half of the articles (67/117, 57.3%) were primary research studies with original data, while one third of all the studies (33.3%) were secondary research articles (e.g., review articles). The remaining articles were clinical recommendations / position papers (7/117, 6.0%) and other types of articles (3.4%). The majority of articles focused on POCT use in infectious diseases (44/117, 37.6%), diabetic syndromes (15.4%), cardiac disease (12.0%) or coagulopathies and thrombosis (10.3%), while the remaining articles did not specify the disease (13.7%) or investigated other diseases (11.1%). Similar to international studies, most primary research studies investigated the diagnostic performance of POCT (e.g., sensitivity, specificity). Evidence beyond diagnostic accuracy remains scarce, such as the impact on therapeutic decisions and practice routines, clinical effectiveness, and user perspectives. In line with this, interventional studies (such as RCTs) on the effectiveness of POCT use in German outpatient care are limited. We define six endpoint domains that should be addressed in the evaluation of POCTs targeted for outpatient care: (i) diagnostic performance, (ii) clinical performance, (iii) time and costs, (iv) impact on clinical routines / processes, (v) perspectives of medical professionals and patients, and (vi) broader aspects.

CONCLUSION

There is considerable research activity on POCTs targeted for use in outpatient care in Germany. Data on their potential benefits beyond diagnostic accuracy is often lacking and should be addressed in future POCT research studies.

Point-of-care HIV and hepatitis screening in community pharmacies: a quantitative and qualitative study

Background

Point-of-care tests can contribute to earlier diagnosis and treatment of infectious diseases, thereby affording the opportunity to prevent chronic stages and the spread to others. As part of the Fast-Track Cities initiative, a pilot study was initiated in community pharmacies in Portugal.

Aim

To characterize the individuals choosing to have point-of-care testing or screening for human immunodeficiency virus, hepatitis C, and hepatitis B virus infections in community pharmacies, their risk behaviours and motivations to perform the tests, as well as to understand the facilitators and barriers from the perspective of pharmacists.

Method

A quantitative and qualitative study was conducted. A survey was applied to test users in pharmacies between May and December 2019, and three focus groups were conducted with six, four, and five pharmacists involved in the initiative. Qualitative data were analysed according to thematic content analysis.

Results

A total of 210 questionnaires were collected (57.9% response rate). Point-of-care test users were predominantly male, mean age of 35 (± 13.0) years, the majority had higher education level, and 22.8% were born outside of Portugal. Almost half of the users were first time tested and the main reason for screening was unprotected sexual intercourse. Pharmacists identified speed, confidentiality, counselling provided to users, pharmacists’ initial training to perform the tests, and trust in the pharmacist as facilitators of these tests. Stigma associated with infections, the procedure, logistical conditions, and the referral process were considered as barriers.

Conclusion

Pharmacies are a screening site with special importance for individuals who are first tested, heterosexuals, and some migrants. Nevertheless, it is necessary to understand and reduce barriers and increase the support to specific groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11096-022-01444-1.

"It was difficult to offer same day results": evaluation of community-based point-of-care testing for sexually transmitted infections among youth using the GeneXpert platform in Zimbabwe

BACKGROUND

Point-of-care testing for sexually transmitted infections (STIs) may improve diagnosis and treatment of STIs in low- and middle-income counties. We explored the facilitators and barriers to point-of-care testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG) for youth in community-based settings in Zimbabwe.

METHODS

This study was nested within a cluster randomised trial of community-based delivery of integrated HIV and sexual and reproductive health services for youth aged 16 to 24 years. On-site CT/NG testing on urine samples using the Xpert® CT/NG test was piloted in four intervention clusters, with testing performed by service providers. On-site testing was defined as sample processing on the same day and site as sample collection. Outcomes included proportion of tests processed on-site, time between sample collection and collection of results, and proportion of clients receiving treatment. In-depth interviews were conducted with nine service providers and three staff members providing study co-ordination or laboratory support to explore facilitators and barriers to providing on-site CT/NG testing.

RESULTS

Of 847 Xpert tests, 296 (35.0%) were performed on-site. Of these, 61 (20.6%) were positive for CT/NG; one (1.6%) received same day aetiological treatment; 33 (54.1%) presented later for treatment; and 5 (8.2%) were treated as a part of syndromic management. There was no difference in the proportion of clients who were treated whether their sample was processed on or off-site (64% (39/61) vs 60% (66/110); p = 0.61). The median (IQR) number of days between sample collection and collection of positive results was 14 (7-35) and 14 (7-52.5) for samples processed on and off-site, respectively, The interviews revealed four themes related to the provision of on-site testing associated with the i) diagnostic device ii) environment, iii) provider, and iv) clients. Some of the specific barriers identified included insufficient testing capacity, inadequate space, as well as reluctance of clients to wait for their results.

CONCLUSIONS

In addition to research to optimise the implementation of point-of-care tests for STIs in resource-limited settings, the development of new platforms to reduce analytic time will be necessary to scale up STI testing and reduce the attrition between testing and treatment.

TRIAL REGISTRATION

Registered in clinical trials.gov ( NCT03719521 ).

Metabolomics for personalized medicine: the input of analytical chemistry from biomarker discovery to point-of-care tests

Metabolomics refers to the large-scale detection, quantification, and analysis of small molecules (metabolites) in biological media. Although metabolomics, alone or combined with other omics data, has already demonstrated its relevance for patient stratification in the frame of research projects and clinical studies, much remains to be done to move this approach to the clinical practice. This is especially true in the perspective of being applied to personalized/precision medicine, which aims at stratifying patients according to their risk of developing diseases, and tailoring medical treatments of patients according to individual characteristics in order to improve their efficacy and limit their toxicity. In this review article, we discuss the main challenges linked to analytical chemistry that need to be addressed to foster the implementation of metabolomics in the clinics and the use of the data produced by this approach in personalized medicine. First of all, there are already well-known issues related to untargeted metabolomics workflows at the levels of data production (lack of standardization), metabolite identification (small proportion of annotated features and identified metabolites), and data processing (from automatic detection of features to multi-omic data integration) that hamper the inter-operability and reusability of metabolomics data. Furthermore, the outputs of metabolomics workflows are complex molecular signatures of few tens of metabolites, often with small abundance variations, and obtained with expensive laboratory equipment. It is thus necessary to simplify these molecular signatures so that they can be produced and used in the field. This last point, which is still poorly addressed by the metabolomics community, may be crucial in a near future with the increased availability of molecular signatures of medical relevance and the increased societal demand for participatory medicine.

A systematic review and meta-analysis

BACKGROUND

Point-of-care tests could be essential in differentiating bacterial and viral acute community-acquired lower respiratory tract infections and driving antibiotic stewardship in the community.

OBJECTIVES

To assess diagnostic test accuracy of point-of-care tests in community settings for acute community-acquired lower respiratory tract infections.

DATA SOURCES

Multiple databases (MEDLINE, EMBASE, Web of Science, Cochrane Library, Open Gray) from inception to 31 May 2021, without language restrictions.

STUDY ELIGIBILITY CRITERIA

Diagnostic test accuracy studies involving patients at primary care, outpatient clinic, emergency department and long-term care facilities with a clinical suspicion of acute community-acquired lower respiratory tract infections. The comparator was any test used as a comparison to the index test. In order not to limit the study inclusion, the comparator was not defined a priori.

ASSESSMENT OF RISK OF BIAS

Four investigators independently extracted data, rated risk of bias, and assessed the quality using QUADAS-2.

METHODS OF DATA SYNTHESIS

The measures of diagnostic test accuracy were calculated with 95% CI.

RESULTS

A total of 421 studies addressed at least one point-of-care test. The diagnostic performance of molecular tests was higher compared with that of rapid diagnostic tests for all the pathogens studied. The accuracy of stand-alone signs and symptoms or biomarkers was poor. Lung ultrasound showed high sensitivity and specificity (90% for both) for the diagnosis of bacterial pneumonia. Rapid antigen-based diagnostic tests for influenza, respiratory syncytial virus, human metapneumovirus, and Streptococcus pneumoniae had sub-optimal sensitivity (range 49%-84%) but high specificity (>80%).

DISCUSSION

Physical examination and host biomarkers are not sufficiently reliable as stand-alone tests to differentiate between bacterial and viral pneumonia. Lung ultrasound shows higher accuracy than chest X-ray for bacterial pneumonia at emergency department. Rapid antigen-based diagnostic tests cannot be considered fully reliable because of high false-negative rates. Overall, molecular tests for all the pathogens considered were found to be the most accurate.

Can we trust in Sars-CoV-2 rapid antigen testing? Preliminary results from a paediatric cohort in the emergency department

Background

Rapid identification of Covid-19 in the paediatric emergency department is critical; Antigen tests are fast but poorly investigated in children.

Aims

To investigate Sars-CoV-2 antigen rapid test in children.

Methods

We compare the performance of LumiraDx with molecular tests in a paediatric emergency department.

Results

A retrospective cohort of 191 patients with AT and PCR tests performed in the same episode was analysed; 16% resulted positive for Sars-CoV-2. Using the PCR test as the gold standard, we calculated antigen testing overall sensitivity of 94.1%, specificity of 91.9%, and NPV of 99.4%. Only one false-negative test was found.

Conclusions

AT may be helpful in the initial screening of patients at PED.

Development of an Integrated Optical Sensor for Determination of β-Hydroxybutyrate Within the Microplatform

Ketone bodies (acetoacetate, beta-hydroxybutyrate (βHB), acetone) are generated as a result of fatty acid oxidation in the liver and exist at low concentrations in urine and blood. Elevated concentrations can indicate health problems such as diabetes, childhood hypoglycemia, alcohol, or salicylate poisoning. Development of portable and cost-effective bedside point-of-care (POC) tests to detect such compounds can help to reduce the risk of disease progression. In this study, βHB was chosen as a model molecule for developing an optical sensor-integrated microplatform. Prior to sensor optimization, βHB levels were measured at a concentration range of 0.02 and 0.1 mM spectrophotometrically, which is far below the reported elevated ranges of 1-2 mM and resulting absorbance changes were converted into an Arduino microcontroller code for the correlation. Measurements performed with the designed integrated microplatform were found significant. Integrated microplatform was verified with the benchtop spectrophotometer. Measurements between 0.02 and 0.1 mM substrate concentration were found highly sensitive with "y = 0.7347x + 0.00184" with R² value of 0.9796, and the limit of detection was determined as 0.02 mM. Based on these results, the proposed system will allow on-site and early intervention.

Rapid community point-of-care testing for COVID-19 (RAPTOR-C19): protocol for a platform diagnostic study

BACKGROUND

The aim of RApid community Point-of-care Testing fOR COVID-19 (RAPTOR-C19) is to assess the diagnostic accuracy of multiple current and emerging point-of-care tests (POCTs) for active and past SARS-CoV2 infection in the community setting. RAPTOR-C19 will provide the community testbed to the COVID-19 National DiagnOstic Research and Evaluation Platform (CONDOR).

METHODS

RAPTOR-C19 incorporates a series of prospective observational parallel diagnostic accuracy studies of SARS-CoV2 POCTs against laboratory and composite reference standards in patients with suspected current or past SARS-CoV2 infection attending community settings. Adults and children with suspected current SARS-CoV2 infection who are having an oropharyngeal/nasopharyngeal (OP/NP) swab for laboratory SARS-CoV2 reverse transcriptase Digital/Real-Time Polymerase Chain Reaction (d/rRT-PCR) as part of clinical care or community-based testing will be invited to participate. Adults (≥ 16 years) with suspected past symptomatic infection will also be recruited. Asymptomatic individuals will not be eligible. At the baseline visit, all participants will be asked to submit samples for at least one candidate point-of-care test (POCT) being evaluated (index test/s) as well as an OP/NP swab for laboratory SARS-CoV2 RT-PCR performed by Public Health England (PHE) (reference standard for current infection). Adults will also be asked for a blood sample for laboratory SARS-CoV-2 antibody testing by PHE (reference standard for past infection), where feasible adults will be invited to attend a second visit at 28 days for repeat antibody testing. Additional study data (e.g. demographics, symptoms, observations, household contacts) will be captured electronically. Sensitivity, specificity, positive, and negative predictive values for each POCT will be calculated with exact 95% confidence intervals when compared to the reference standard. POCTs will also be compared to composite reference standards constructed using paired antibody test results, patient reported outcomes, linked electronic health records for outcomes related to COVID-19 such as hospitalisation or death, and other test results.

DISCUSSION

High-performing POCTs for community use could be transformational. Real-time results could lead to personal and public health impacts such as reducing onward household transmission of SARS-CoV2 infection, improving surveillance of health and social care staff, contributing to accurate prevalence estimates, and understanding of SARS-CoV2 transmission dynamics in the population. In contrast, poorly performing POCTs could have negative effects, so it is necessary to undertake community-based diagnostic accuracy evaluations before rolling these out.

TRIAL REGISTRATION

ISRCTN, ISRCTN14226970.

Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies Evaluating Point-of-Care Tests of Coagulopathy in Cardiac Surgery

Treatment guidelines recommend the routine use of point-of-care diagnostic tests for coagulopathy in the management of cardiac surgery patients at risk of severe bleeding despite uncertainty as to their diagnostic accuracy. We performed a systematic review and meta-analysis of studies that evaluated the diagnostic accuracy of viscoelastometry, platelet function tests, and modified thromboelastography (TEG) tests, for coagulopathy in cardiac surgery patients. The reference standard included resternotomy for bleeding, transfusion of non-red cell components, or massive transfusion. We searched MEDLINE, EMBASE, CINAHL, and Clinical Trials.gov, from inception to June 2019. Study quality was assessed using QUADAS-2. Bivariate models were used to estimate summary sensitivity and specificity with (95% confidence intervals). All 29 studies (7440 participants) included in the data synthesis evaluated the tests as predictors of bleeding. No study evaluated their role in the management of bleeding. None was at low risk of bias. Four were judged as low concern regarding applicability. Pooled estimates of diagnostic accuracy were; Viscoelastic tests, 12 studies, sensitivity 0.61 (0.44, 0.76), specificity 0.83 (0.70, 0.91) with significant heterogeneity. Platelet function tests, 12 studies, sensitivity 0.63 (0.53, 0.72), specificity 0.75 (0.64, 0.84) with significant heterogeneity. TEG modification tests, 3 studies, sensitivity 0.80 (0.67, 0.89), specificity 0.76 (0.69, 0.82) with no evidence of heterogeneity. Studies reporting the highest values for sensitivity and specificity had important methodological limitations. In conclusion, we did not demonstrate predictive accuracy for commonly used point-of-care devices for coagulopathic bleeding in cardiac surgery. However, the certainty of the evidence was low.

Laboratory diagnosis of novel corona virus (2019-nCoV)-present and the future

Background

In December 2019 a novel coronavirus SARS-CoV-2 emerged in the Hunan seafood market in Wuhan, China, and soon became a global health problem. Since its outbreak, SARS-CoV-2 has had a major impact on clinical diagnostic laboratories. The scientific community has quickly risen to the occasion and reports of new developments have arrived at an unprecedented scale. At present, there is a growing list of over 400 SARC-CoV-2 diagnostic tests either in development or approved for clinical use. This presentation reviews the current laboratory methods available for testing COVID- 19 in microbiology laboratories and also provides an insight into the future diagnostics approaches.

Methods

Proper respiratory specimen collected at the appropriate time and from the right anatomical site is critical in the accurate and timely diagnosis of SARSCoV2. While oropharyngeal and nasopharyngeal swabs are recommended for the detection of early infection, other lower respiratory tract specimens like the sputum and bronchoalveolar lavage are used for late detection and monitoring of patients with severe COVID-19 pneumonia.

Results and Conclusion

Real-time RT-PCR based molecular assay remains the test of choice for the etiological diagnosis of SARS-CoV-2 while serological tests are being introduced as supplementary tools. Finally, there is an urgent need for scaling up the diagnostic capacity by the introduction of reliable and accurate point-of-care tests which will assist in effective control of this outbreak. These assays can be used in the local hospitals and clinics bearing the burden of identifying and treating patients.

•

At present, there is a growing list of over 400 SARC-CoV-2 diagnostic tests either in development or approved for clinical use.

•

Real-time RT-PCR based molecular assay remains the test of choice for the etiological diagnosis of SARS-CoV-2.

•

Oropharyngeal and nasopharyngeal swabs are recommended for the detection of early infection.

•

Lower respiratory tract specimens can be used for late detection and monitoring of patients with severe COVID-19 pneumonia.

•

There is an urgent need for scaling up the diagnostic capacity by the introduction of reliable POC tests.

Urine protein biomarkers for the detection, surveillance, and treatment response prediction of bladder cancer

The "gold standard" diagnostic procedure for bladder cancer is cystoscopy, a technique that can be invasive, expensive, and a possible cause of urinary tract infection. Unlike techniques such as histology, PCR, and staining, assays for protein biomarkers lend themselves well to the creation of efficient point-of-care tests, which are easy to use and yield fast results. A couple of urine-based tests have been approved by the U.S. FDA, but these tests suffer from low sensitivity. Hence, there is clearly a need for more reliable non-invasive biomarkers of bladder cancer. Urinary biomarkers are particularly attractive due to the direct contact of the urine with the urothelial tumor and the ease of sample collection. With these considerations, this review aims to provide a comprehensive listing of the most promising protein biomarkers of bladder cancer in urine. Biomarkers are organized by their potential role in detection, surveillance, or monitoring of treatment response. The purpose of this review is to assess progress towards the goal of identifying ideal urinary proteins for use in each of the above three biomarker applications in bladder cancer.

Comparisons of New HIV Rapid Test Kit Performance

The development of rapid point-of-care tests for HIV infection has greatly reduced the problem of failure to return for test results. Test manufacturers are now developing test kits that can test for two or even three diseases at the same time, multiple-disease test kits. This study reports on the sensitivity and specificity of HIV tests when included on multi-disease test kits. 1029 participants were recruited from 2011 to 2014. HIV test kit sensitivities ranged from 91.1 to 100%, and the HIV test kit specificities from 99.5 to 100%. The two HIV kits which used oral fluid instead of blood performed well.

Understanding the adoption and use of point-of-care tests in Dutch general practices using multi-criteria decision analysis

BACKGROUND

The increasing number of available point-of-care (POC) tests challenges clinicians regarding decisions on which tests to use, how to efficiently use them, and how to interpret the results. Although POC tests may offer benefits in terms of low turn-around-time, improved patient's satisfaction, and health outcomes, only few are actually used in clinical practice. Therefore, this study aims to identify which criteria are, in general, important in the decision to implement a POC test, and to determine their weight. Two POC tests available for use in Dutch general practices (i.e. the C-reactive protein (CRP) test and the glycated haemoglobin (HbA_1c) test) serve as case studies. The information obtained from this study can be used to guide POC test development and their introduction in clinical practice.

METHODS

Relevant criteria were identified based on a literature review and semi-structured interviews with twelve experts in the field. Subsequently, the criteria were clustered in four groups (i.e. user, organization, clinical value, and socio-political context) and the relative importance of each criterion was determined by calculating geometric means as implemented in the Analytic Hierarchy Process. Of these twelve experts, ten participated in a facilitated group session, in which their priorities regarding both POC tests (compared to central laboratory testing) were elicited.

RESULTS

Of 20 criteria in four clusters, the test's clinical utility, its technical performance, and risks (associated with the treatment decision based on the test result) were considered most important for using a POC test, with relative weights of 22.2, 12.6 and 8.5%, respectively. Overall, the experts preferred the POC CRP test over its laboratory equivalent, whereas they did not prefer the POC HbA_1c test. This difference was mainly explained by their strong preference for the POC CRP test with regard to the subcriterion 'clinical utility'.

CONCLUSIONS

The list of identified criteria, and the insights in their relative impact on successful implementation of POC tests, may facilitate implementation and use of existing POC tests in clinical practice. In addition, having experts score new POC tests on these criteria, provides developers with specific recommendations on how to increase the probability of successful implementation and use.

Point-of-care diagnostics: needs of African health care workers and their role combating global antimicrobial resistance

Point-of-care tests (POCTs) offer the opportunity for increased diagnostic capacity in resource-limited settings, where there is lack of electricity, technical capacity, reagents, and infrastructure. Understanding how POCTs are currently used and determining what health care workers (HCWs) need is key to development of appropriate tests. In 2016, we undertook an email survey of 7584 HCWs who had received training at the Infectious Diseases Institute, Uganda, in a wide variety of courses. HCWs were contacted up to three times and asked to complete the survey using Qualtrics software. Of 555 participants answering the survey (7.3% response rate), 62% completed. Ninety-one percent were from Uganda and 50.3% were male. The most commonly-used POCTs were pregnancy tests (74%), urine dipstick (71%), syphilis rapid test (66%), and Gram stain (41%). The majority (74%) practiced syndromic diagnosis for sexually transmitted infections/HIV. Lack of availability of POCTs, increased patient wait time, and lack of training were the leading barriers for POCT use. Increasing POCT availability and training could improve uptake of POCTs for sexually transmitted infections in Africa and decrease syndromic management. This could reduce overtreatment and slow the emergence of antibiotic resistance. This is the first published email survey of HCWs in Uganda; mechanisms to increase the response rate should be evaluated.

Evaluation for occult sepsis incorporating NIRS and emergency sonography

PURPOSE

We aim to determine whether the combination of regional tissue oxygen saturation (StO₂) measurement using near-infrared spectroscopy (NIRS), inferior vena cava (IVC) collapsibility and ejection fraction (EF) is able to detect occult sepsis.

METHODS

We included adult patients in the emergency department with at least one of the following: fever; any one component of the quick sepsis-related organ function assessment (SOFA) score; heart rate≥100 beats per minute; or white cell count <4.0×10⁹/L or >12.0×10⁹/L. StO₂ parameters, IVC collapsibility and EF were assessed. Primary outcome was composite of admission to intensive care unit, hypotension requiring fluid resuscitation or vasopressor use, and antibiotic escalation.

RESULTS

We included 184 patients with mean age of 55.4years and slight male predominance (51.6%). Increase in temperature (adjusted odds ratio [aOR] 3.05; 95% confidence interval [CI] 1.16 to 8.02), higher white cell counts (aOR 1.10; 95% CI 1.03 to 1.19), increase in time taken to new StO₂ baseline (aOR 1.03; 95% CI 1.01 to 1.06) and reduced EF (aOR 33.9; 95% CI 2.19 to 523.64) had higher odds of achieving the primary outcome.

CONCLUSION

Change in StO₂ and time taken to reach new StO₂ baseline, combined with EF could potentially predict sepsis among patients with infection.

Self-tests for influenza: an empirical ethics investigation

BACKGROUND

In this article we aim to assess the ethical desirability of self-test diagnostic kits for influenza, focusing in particular on the potential benefits and challenges posed by a new, mobile phone-based tool currently being developed by i-sense, an interdisciplinary research collaboration based (primarily) at University College London and funded by the Engineering and Physical Sciences Research Council.

METHODS

Our study adopts an empirical ethics approach, supplementing an initial review into the ethical considerations posed by such technologies with qualitative data from three focus groups.

RESULTS

Overall, we map a range of possible considerations both for and against the use of such technologies, synthesizing evidence from a range of secondary literature, as well as identifying several new considerations previously overlooked.

CONCLUSIONS

We argue that no single consideration marks these technologies as either entirely permissible or impermissible but rather tools which have the potential to incur certain costs and benefits, and that context is important in determining these. In the latter stages of the article, we explain how developers of such technologies might seek to mitigate such costs and reflect on the possible limitations of the empirical ethics method brought out during the study.

TRIAL REGISTRATION

Not applicable.

Exploring the barriers and facilitators to use of point of care tests in family medicine clinics in the United States

Background

Point-of-care tests (POCTs) are increasingly used in family medicine clinics in the United States. While the diagnostics industry predicts significant growth in the number and scope of POCTs deployed, little is known about clinic-level attitudes towards implementation of these tests. We aimed to explore attitudes of primary care providers, laboratory and clinic administrative/support staff to identify barriers and facilitators to use of POCTs in family medicine.

Methods

Seven focus groups and four semi-structured interviews were conducted with a total of 52 clinic staff from three family medicine clinics in two US states. Qualitative data from this exploratory study was analyzed using the constant comparison method.

Results

Five themes were identified which included the impact of POCTs on clinical decision-making; perceived inaccuracy of POCTs; impact of POCTs on staff and workflow; perceived patient experience and patient-provider relationship, and issues related to cost, regulation and quality control. Overall, there were mixed attitudes towards use of POCTs. Participants believed the added data provided by POCT may facilitate prompt clinical management, diagnostic certainty and patient-provider communication.

Perceived barriers included inaccuracy of POCT, shortage of clinic staff to support more testing, and uncertainty about their cost-effectiveness.

Conclusions

The potential benefits of using POCTs in family medicine clinics are countered by several barriers. Clinical utility of many POCTs will depend on the extent to which these barriers are addressed. Engagement between clinical researchers, industry, health insurers and the primary care community is important to ensure that POCTs align with clinic and patient needs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12875-016-0549-1) contains supplementary material, which is available to authorized users.

Estimating the uptake of maternal syphilis screening and other antenatal interventions before and after national rollout of syphilis point-of-care testing in Ghana

OBJECTIVE

To compare the uptake of maternal syphilis and HIV screening, intermittent preventive treatment for malaria, and tetanus toxoid administration in three regions of Ghana, before and after the rollout of syphilis point-of-care tests (POCTs).

METHODS

Antenatal register records were reviewed in 15 selected health facilities over an eight-month period, 16 months apart. Register records had been evaluated using the maternal record booklets as a gold standard in a separate prior survey.

RESULTS

In the evaluation study, the sensitivity of register data was low, ranging from 33.3% for tetanus toxoid administration to 53.8% for syphilis serology. In total, 8282 antenatal client records (4141 in each period) were reviewed. Less than a third of pregnant women received any single intervention at either period (ranging from 17.8% for tetanus toxoid to 29.8% for HIV testing). Overall, HIV screening had a marginal absolute increase of about 2% while the remaining interventions experienced non-significant absolute decreases of 4.1 to 11.1%. When adjusting for under-recording, syphilis screening uptake was 50% before and 33.6% after the introduction of POCTs.

CONCLUSION

Use of POCTs for syphilis did not result in increased uptake. Routine monitoring of antenatal interventions using the antenatal register may result in underestimation of their uptake.

Canadian Public Health Laboratory Network laboratory guidelines for the use of point-of-care tests for the diagnosis of syphilis in Canada

Syphilis point-of-care tests (POCT) are widely available in developing countries enabling early diagnosis, treatment and support. The majority of commercially available tests use treponemal antigens and the presence of antibodies does not distinguish between current and past infection, which may lead to unnecessary antibiotic use and stigmatization of having a current STI. In hard-to-reach populations, the benefits may outweigh the risks. Available studies show reasonable performance of POCT with median sensitivity of 86%, specificity of 99% and positive predictive values >80% when prevalence was >0.3%. Although no syphilis POCT are approved in Canada at this time, a single study in an outreach setting in Alberta showed limited benefit due to a high prevalence of previous infection but more studies are needed. Newer dual tests employing treponemal and nontreponemal antigens look promising.