Point-of-care urine culture for managing urinary tract infection in primary care: a randomised controlled trial of clinical and cost-effectiveness

Cost-effectiveness of point-of-care diagnostics for AMR: a systematic review

BACKGROUND

Antimicrobial resistance (AMR) is a major threat to global health. By 2050, it is forecast that AMR will cause 10 million deaths and cost 100 trillion USD annually. Point-of-care tests (POCTs) may represent a cost-effective approach to reduce AMR.

OBJECTIVES

We systematically reviewed which POCTs addressing AMR have undergone economic evaluation in primary and secondary healthcare globally, how these POCTs have been economically evaluated, and which are cost-effective in reducing antimicrobial prescribing or the burden of AMR. Clinical cost-effectiveness was additionally addressed.

METHODS

This systematic review, accordant with PRISMA guidelines, was pre-registered on PROSPERO (CRD42022315192). MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched from 2000 to 2023 for relevant publications. Quality assessment was performed using the Consensus of Health Economic Criteria.

RESULTS

The search strategy identified 1421 studies, of which 20 met the inclusion criteria. The most common POCTs assessed were for respiratory infections (n = 10), STIs (n = 3), and febrile patients in low- and middle-income countries (n = 3). All studies assessed costs from a healthcare provider perspective; five additionally considered the societal cost of AMR.Eighteen studies identified POCT strategies that reduced antimicrobial prescribing. Of these, 10 identified POCTs that would be considered cost-effective at a willingness-to-pay (WTP) threshold of £33.80 per antibiotic prescription avoided. Most POCT strategies improved clinical outcomes (n = 14); the remainder were clinically neutral.

CONCLUSIONS

There is evidence that some POCTs are cost-effective in reducing antimicrobial prescribing, with potential concomitant clinical benefits. Such interventions-especially CRP POCTs in both high- and low-income settings-merit further, large-scale clinical evaluation.

Analysis and mapping of global research publications on point-of-care testing for infectious diseases

RATIONALE

This study presents the first comprehensive analysis and mapping of scientific research on point-of-care testing (POCT) in infectious diseases, filling a gap in understanding the evolving landscape of this field. The identification of research themes and global contributions offers valuable insights.

AIMS AND OBJECTIVES

This manuscript aims to analyse and map scientific research on POCT in the context of infectious diseases.

METHODS

The study employed a comprehensive search strategy using terms related to POCT and infectious diseases. The search was conducted on the Scopus database, refining results based on inclusion and exclusion criteria. The dataset of 1719 research articles was then subjected to descriptive analysis and mapping using VOSviewer.

RESULTS

The research findings indicate an exponential growth in POCT-related publications, with 46.8% published post the COVID-19 pandemic. Plos One journal led in publication frequency, and Biosensors and Bioelectronics received the highest citations per article. North America and Western Europe dominated contributions, with notable participation from China, South Africa, and India. The research landscape revealed the following research themes: detection technologies, human immunodeficiency virus (HIV)/sexually transmitted infection (STI) diagnosis, antibiotic optimisation, and schistosomiasis. Clinical trials focused on antibiotic prescribing, HIV, STIs, and specific infections. The findings suggest a shifting landscape towards POCT, emphasising the need for future planning and investment in healthcare systems. The research identifies areas for future exploration, such as the impact of POCT on antibiotic prescribing and its role in combating infectious diseases in low- and middle-income countries.

CONCLUSION

Implementation of POCT has the potential to revolutionise infectious disease management, improve patient outcomes, and reduce the global burden of diseases. Better public awareness, healthcare team management, and planning for POCT at entry points are crucial for societal benefit. Results demonstrated the evolving role of POCT in infectious disease management and prevention.

Dipsticks and point-of-care Microscopy to reduce antibiotic use in women with an uncomplicated Urinary Tract Infection (MicUTI): protocol of a randomised controlled pilot trial in primary care

INTRODUCTION

Uncomplicated urinary tract infections (uUTIs) in women are common infections encountered in primary care. Evidence suggests that rapid point-of-care tests (POCTs) to detect bacteria and erythrocytes in urine at presentation may help primary care clinicians to identify women with uUTIs in whom antibiotics can be withheld without influencing clinical outcomes. This pilot study aims to provide preliminary evidence on whether a POCT informed management of uUTI in women can safely reduce antibiotic use.

METHODS AND ANALYSIS

This is an open-label two-arm parallel cluster-randomised controlled pilot trial. 20 general practices affiliated with the Bavarian Practice-Based Research Network (BayFoNet) in Germany were randomly assigned to deliver patient management based on POCTs or to provide usual care. POCTs consist of phase-contrast microscopy to detect bacteria and urinary dipsticks to detect erythrocytes in urine samples. In both arms, urine samples will be obtained at presentation for POCTs (intervention arm only) and microbiological analysis. Women will be followed-up for 28 days from enrolment using self-reported symptom diaries, telephone follow-up and a review of the electronic medical record. Primary outcomes are feasibility of patient enrolment and retention rates per site, which will be summarised by means and SDs, with corresponding confidence and prediction intervals. Secondary outcomes include antibiotic use for UTI at day 28, time to symptom resolution, symptom burden, number of recurrent and upper UTIs and re-consultations and diagnostic accuracy of POCTs versus urine culture as the reference standard. These outcomes will be explored at cluster-levels and individual-levels using descriptive statistics, two-sample hypothesis tests and mixed effects models or generalised estimation equations.

ETHICS AND DISSEMINATION

The University of Würzburg institutional review board approved MicUTI on 16 December 2022 (protocol n. 109/22-sc). Study findings will be disseminated through peer-reviewed publications, conferences, reports addressed to clinicians and the local citizen's forums.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT05667207.

Clinical effectiveness of point of care tests for diagnosing urinary tract infection: a systematic review

BACKGROUND

Point of care tests (POCTs) have the potential to improve the urinary tract infection (UTI) diagnostic pathway, as they can provide a diagnosis quickly in near-patient settings, and some also identify causative pathogens/antimicrobial sensitivity.

OBJECTIVES

To assess the clinical impact, accuracy, and technical characteristics of POCT for diagnosing UTI.

METHODS OF DATA SYNTHESIS

Narrative summary and bivariate random effects meta-analyses to estimate summary sensitivity and specificity.

DATA SOURCES

Five electronic databases, two clinical trial registries, study reports and review reference lists, and websites.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials/non-randomized studies and diagnostic test accuracy studies published since 2000.

PARTICIPANTS

People with suspected UTI.

TESTS

Rapid tests (results <40 minutes): Astrego PA-100 system, Lodestar DX, Uriscreen, UTRiPLEX. Culture tests (results <24 hours): Flexicult Human, ID Flexicult, Diaslide, Dipstreak, Chromostreak, Uricult, Uricult Trio, Uricult Plus.

REFERENCE STANDARD

Any.

ASSESSMENT OF RISK OF BIAS

Risk of Bias-2, Quality Assessment of Diagnostic Accuracy Studies-2, Quality Assessment of Diagnostic Accuracy Studies-C.

RESULTS

Two randomized controlled trials evaluated Flexicult Human (one against standard care; one against ID Flexicult). No difference was reported in antibiotic use concordant with culture results (OR 0.84 95% CI 0.58-1.20) or appropriate antibiotic prescribing (OR 1.44 95% CI 1.03-1.99). Initial antibiotic prescribing was lower with Flexicult than standard care (OR 0.56 95% CI 0.35-0.88). No difference for other measures of antibiotic use, symptom duration, patient enablement, or resource use. Fifteen studies reported accuracy data. Limited data were available, with most POCT evaluated in single studies or not evaluated at all. Uriscreen (four studies), Uricult Trio (three studies), Flexicult Human (four studies), and ID Flexicult (two studies) had modest sensitivity and specificity. POCTs were easier to use and interpret than standard culture.

CONCLUSIONS

There is currently insufficient evidence to support the use of POCTs in UTI diagnosis. Due to the rapid development of POCT, this review should be updated regularly.

Delayed and Non-Antibiotic Therapy for Urinary Tract Infections: A Literature Review

Urinary tract infections are among the most common infections encountered in the clinic and remain a top indication for women to receive antibiotics. Delayed antibiotic prescribing and non-antibiotic symptomatic therapies are treatment paradigms common to other uncomplicated infectious diseases, such as upper respiratory infections. We aimed to review the literature on delayed antibiotics and non-antibiotic treatments as alternatives to immediate antibiotic prescriptions for uncomplicated cystitis. A literature search was performed in PubMed, Google Scholar, and Web of Science to identify relevant clinical trials and reference lists of included articles were examined to find additional studies. All published trials where same day treatment with antibiotics was compared to scenarios where antibiotics were intentionally delayed or withheld or where antibiotics were compared to non-antimicrobial agents or placebo were analyzed. A total of 13 articles were included. Trials were grouped into categories based on their comparator groups: placebo (n = 5), delayed antibiotic therapy (n = 3), and symptomatic treatment (n = 5). Antibiotic delay and ibuprofen, while less effective than antibiotics in early microbiologic and clinical cure, may still be considered plausible alternatives to immediate antibiotic treatment in non-pregnant women with cystitis. Day 7 and later symptomatic resolution ranges from 26-75% with delayed or placebo therapy and 70-83% with nonsteroidal anti-inflammatory drugs. Symptom improvement, however, may be delayed compared to immediate antibiotics. These approaches have shown to decrease antibiotic use in primary care settings with low rates of pyelonephritis. Methodology included in these studies may be considered in stewardship interventions for outpatient clinics.

Performance of an innovative culture-based digital dipstick for detection of bacteriuria

IMPORTANCE

In this study, we explore the transformative potential of UTI-lizer, an emerging technology not yet commercially available. Our manuscript shows that UTI-lizer is a promising alternative for detecting the five main pathogens that cause urinary tract infections (UTIs). The results also indicate that digital dipsticks have the potential to uniquely provide UTI diagnostic quality on par with that of gold-standard testing, with the added benefits of ease of testing, rapid test handling time, and simple test equipment. This technology can be helpful in quickly ruling out bacterial infections and reducing the unnecessary use of antibiotics, especially in primary care settings or at the point of care. Moreover, the UTI-lizer test can reduce the number of negative urine samples sent to central laboratories, thus easing the burden of UTI diagnostics on the healthcare system. We believe our study, as well as current and upcoming research based on this technology, is highly relevant for clinical microbiologists, microbiology scientists, general practitioners, and urologists.

Increased demand of urine cultures from Danish general practice: a five-year register-based study

OBJECTIVE

To characterise and explore the development in the number and content of urine samples sent from general practice in the North Denmark Region to the Department of Clinical Microbiology (DCM) at Aalborg University Hospital during a five-year period.

DESIGN

A register-based study.

SETTING

General practice.

SUBJECTS

Urine samples received at DCM, Aalborg University Hospital from general practice between 2017 and 2022.

MAIN OUTCOME MEASURES

Number and content of urine samples.

RESULTS

A total of 255,271 urine samples from general practice were received at DCM, with 76.1% being from female patients. Uropathogens were identified in 43.0% of the samples. During the five-year period, a 23.0% increase in the number of urine samples per person (incidence rate ratio (IRR) 1.23, 95% CI 1.21-1.25) was observed. A slight increase in the proportion of positive cultures (risk ratio (RR) 1.03, 95% CI 1.01-1.05) was seen. No notable change in the patient population (age, gender) was observed. Overall, Escherichia coli was the most identified uropathogen (60.4%) followed by Klebsiella spp. (8.7%) and Enterococcus spp. (7.7%). Distribution of the various uropathogens differed slightly depending on patient gender and age, importantly E. coli was less frequently observed in males aged >65 years.

CONCLUSION

During the past five years an increasing amount of urine cultures have been requested at DCM from general practice. Importantly, the cause(s) of this increasing demand needs to be explored further in future studies.

Economic evaluation of antimicrobial stewardship in primary care: a systematic review and quality assessment

Background

Primary care accounts for 80%–90% of antimicrobial prescriptions, making this setting an important focus for antimicrobial stewardship (AMS) interventions.

Objectives

To collate the findings and critically appraise the qualities of economic evaluation studies of AMS or related interventions aimed at reducing inappropriate antimicrobial prescribing in primary care.

Methods

A systematic review of economic evaluations of interventions aimed at reducing inappropriate antimicrobial prescribing in primary care was performed. Published literature were retrieved through a search of Medline, Embase, EconLit and Web of Science databases for the period 2010 to 2020. The quality of the studies was assessed using the Consensus on Health Economic Criteria checklist and Good Practice Guidelines for Decision-Analytic Modelling in Health Technology Assessment.

Results

Of the 2722 records identified, 12 studies were included in the review (8 trial-based and 4 modelled evaluations). The most common AMS interventions were communication skills training for health professionals and C-reactive protein point-of-care testing (CRP-POCT). Types of economic evaluations included in the review were cost-effectiveness (7 studies), cost-utility (1), cost-benefit (2), cost-effectiveness and cost-utility (1) and cost analysis (1). While six of the studies found AMS interventions to be cost-effective, the other six reported them as not cost-effective or inconclusive. The quality of the studies ranged from good to low.

Conclusions

There were significant variations in cost-effectiveness of AMS interventions across studies and depending on the inclusion of cost components such as the cost of antimicrobial resistance. However, communication skills training and CRP-POCT were frequently cost-effective or cost-beneficial for reducing inappropriate antimicrobial prescribing.

Use and quality of point-of-care microscopy, urine culture and susceptibility testing for urinalysis in general practice

Objective: To describe the use and quality of point-of-care (POC) microscopy, urine culture and susceptibility testing performed in general practice in Northern Denmark from 2013 to 2018.Design: Descriptive studySetting: General practices receiving a fee for examining urine samples.Subjects: Simulated urine samples containing uropathogenic bacteria distributed by the organisation for improvement of microbiological quality (MIKAP).Main outcome measures: Percentage of use and correct answers for microscopy, culture and susceptibility testing.Results: A total of 5361 samples were analysed by the use of microscopy (39.7%), culture (66.0%) and/or susceptibility testing (76.5%). For culture, Flexicult SSI urinary kittm (87.6%) demonstrated the highest percentage of correct answers followed by chromogenic agar (85.1%) and 2-plate dipslide (85.2%). Mueller Hinton agar with tablets had the highest percentage of correct answers for susceptibility testing of most bacterial strains (84.6%), followed by Flexicult (77.2%). Furthermore, susceptibility testing with tablets (range: 76.1-84.6%) was found to be more accurate than discs (range: 72.9-75.5%). Overall, the highest percentage of correct answers was obtained when examining urine samples containing Escherichia coli: Microscopy (78.3%), culture (87.0%) and susceptibility testing (range: 84.3-90.7%).Conclusion: The quality of POC testing in general practice was high when examining urine samples containing the most common uropathogen E. coli. Surprisingly, susceptibility testing was more frequently used than culture. This approach may compromise the treatment decision as only cultures contribute with information about the flora composition and bacterial quantification. Interestingly, microscopy was the least used method even though the result may be reached within a few minutes.Key pointsThe quality of POC tests (microscopy, urine culture, susceptibility testing) performed in general practice was high when examining urine containing E. coli, whereas difficulties were observed for samples including S. saprophyticus or K. pneumoniae.Susceptibility testing was more often performed than urine culture, which indicates a problem as only urine cultures contribute with information about the flora composition and bacterial quantification.

OUP accepted manuscript

Introduction

Antimicrobial stewardship interventions (ASIs) aim to reduce the emergence of antimicrobial resistance. We sought to systematically evaluate how microbiological outcomes have been handled and analysed in randomized controlled trials (RCTs) evaluating ASIs.

Methods

We searched PubMed and Embase from 2011–21. Studies were selected if they were RCTs evaluating ASIs. A narrative synthesis approach was taken, identifying whether the study reported any microbiological data (bacterial genus/species; bacterial colony counts; prevalence of bacterial, microbiologically defined infections; and antibiotic susceptibility, measured pre-randomization or post-randomization in one arm only) or outcomes (post-randomization data compared between arms). Studies with or without microbiological data/outcomes were summarized in terms of study characteristics, methods of reporting and analysis of these outcomes.

Results

We identified 117 studies, with 34 (29.1%) collecting microbiological data and 18 (15.4%) reporting microbiological outcomes. Most studies with microbiological outcomes were conducted in secondary care (12/18, 66.7%) and targeted adult populations (14/18, 77.8%), and the intervention involved biomarker-guided rapid diagnostic testing (7/18, 38.9%). The overall quality of reporting and analysing microbiological outcomes was low and inconsistent. The selected study population in analyses and methods of handling missing data were unclear.

Conclusions

This review demonstrates that the quality of handling and reporting microbiological outcomes in RCTs of ASIs was low. The lack of consistency and clarity made it difficult to compare the findings across studies, limiting policy- and clinical decision-making. Therefore, there is a clear need for the development of guidance for handling microbiological outcomes in RCTs and adopting appropriate methods to evaluate these data carefully.

OUP accepted manuscript

Background

Uncomplicated urinary tract infections (UTIs) are amongst the most frequent infections presenting in the outpatient setting. A growing number of clinical trials are assessing the most effective treatment interventions for uncomplicated UTI. Due to the heterogeneity of the outcomes reported in these trials, however, comparing these outcomes is challenging.

Objectives

Identify the core outcomes that have been reported in trials and systematic reviews of interventions treating uncomplicated UTI in adults.

Methods

We conducted a systematic search for core outcomes used to evaluate treatments of UTIs. We searched the Cochrane Database of Systematic Reviews, PubMed and Embase. One researcher independently screened each article for inclusion, and the Core Outcome Set for treatment of Urinary Tract Infections (COSUTI) team acted as second reviewers. All included articles were screened by two reviewers. All outcomes were extracted verbatim, and similar outcomes were grouped into domains and subdomains.

Results

In total, 334 outcomes were reported across 41 papers, the average number of outcomes reported being 8. Outcomes were categorized across 18 domains, the majority of which were related to clinical cure outcomes. Many outcomes varied in the timepoints within which the outcome was measured and reported.

Conclusions

Comparing the outcomes of trials investigating uncomplicated UTI treatment remains challenging due to the difference in outcomes currently reported. Consistency of reporting of outcomes would be improved by developing a minimum number of consistent outcomes that should be reported in all trials.

How Accurate Are Veterinary Clinicians Employing Flexicult Vet for Identification and Antimicrobial Susceptibility Testing of Urinary Bacteria?

Antibiotics are frequently used for treating urinary tract infections (UTI) in dogs and cats. UTI often requires time-consuming and expensive antimicrobial susceptibility testing (AST). Alternatively, clinicians can employ Flexicult Vet, an affordable chromogenic agar with added antibiotics for in-clinic AST. We investigated how well veterinary microbiologists and clinicians, without any prior experience, employ Flexicult Vet for the identification and AST of the most common canine and feline urinary pathogenic bacteria. We prepared 47 monoculture plates containing 10 bacterial species. The test’s mean accuracy was 75.1% for bacteria identification (84.6% and 68.7% for microbiologists and clinicians, respectively) and 79.2% for AST (80.7% and 78.2%). All evaluators employed Flexicult Vet with the accuracies over 90% for the distinctively colored bacteria like Escherichia coli (red), Enterococcus faecalis (turquoise), and Proteus spp. (pale brown). However, the evaluators’ experience proved important in recognizing lightly colored bacteria like Staphylococcus pseudintermedius (accuracies of 82.6% and 40.3%). Misidentifications of E. faecium additionally worsened AST performance since bacterial intrinsic resistance could not be considered. Finally, only 33.3% (3/9) of methicillin-resistant S. pseudintermedius (MRSP) were correctly detected. To conclude, Flexicult Vet proved reliable for certain urinary pathogens. In contrast, light-colored bacteria (e.g., Staphylococcus), often misidentified, require a standard AST.

Antibiotic procurement and ABC analysis for a comprehensive primary health care clinic in the Eastern Cape province, South Africa

BACKGROUND

Antimicrobial resistance (AMR), a major threat to global public health, can be addressed using a managed care approach. This includes timely analysis of antibiotic consumption and procurement data to drive evidence-based policies and practices in healthcare facilities. 'ABC analysis' presents an opportunity for this.

METHODS

ABC analysis data for a comprehensive Primary Health Care (PHC) clinic in the Eastern Cape province of South Africa was obtained from the Provincial Department of Health for 01 April 2015 to 31 March 2018. Procured antibiotics were analysed on the quantities purchased, total cost, route of administration and spectrum of activity. Antibiotic categorization was also carried out according to the World Health Organization Model List of Essential Medicines (WHO EML) 2017.

RESULTS

Antibiotics made up approximately 7% of the total annual pharmaceutical expenditure. A total of 31, 35 and 34 antibiotics were procured in the first, second and third years, respectively. The most procured antibiotics were: (1) isoniazid, (2) flucloxacillin, (3) azithromycin, (4) a combination of rifampicin, isoniazid, pyrazinamide, and ethambutol and (5) amoxicillin. Overall, 55%, 2% and 15% of antibiotics accounted for the 'Access', 'Watch' and 'Access and Watch' categories, respectively, of the WHO EML. No 'Reserve' antibiotics were procured. The remaining 28% were antituberculosis medicines. Altogether, 89%, 8% and 3% of the antibiotics were respectively administered orally, systemically, and topically. A total of 58% were broad-spectrum and 42% were narrow-spectrum antibiotics.

CONCLUSION

Oral antibiotics in the 'Access' category presented favourable usage of antibiotics. Decreasing the use of broad-spectrum antibiotics requires consideration.

Digital dipstick: miniaturized bacteria detection and digital quantification for the point-of-care

Established digital bioassay formats, digital PCR and digital ELISA, show extreme limits of detection, absolute quantification and high multiplexing capabilities. However, they often require complex instrumentation, and extensive off-chip sample preparation. In this study, we present a dipstick-format digital biosensor (digital dipstick) that detects bacteria directly from the sample liquid with a minimal number of steps: dip, culture, and count. We demonstrate the quantitative detection of Escherichia coli (E. coli) in urine in the clinically relevant range of 102-105 CFU ml-1 for urinary tract infections. Our format shows 89% sensitivity to detect E. coli in clinical urine samples (n = 28) when it is compared to plate culturing (gold standard). The significance and uniqueness of this diagnostic test format is that it allows a non-trained operator to detect urinary tract infections in the clinically relevant range in the home setting.

Diagnosis and Management of UTI in Primary Care Settings-A Qualitative Study to Inform a Diagnostic Quick Reference Tool for Women Under 65 Years

Background: To inform interventions to improve antimicrobial use in urinary tract infections (UTIs) and contribute to a reduction in Escherichia coli bloodstream infection, we explored factors influencing the diagnosis and management of UTIs in primary care. Design: Semi-structured focus groups informed by the Theoretical Domains Framework. Setting: General practice (GP) surgeries in two English clinical commissioning groups (CCGs), June 2017 to March 2018. Participants: A total of 57 GP staff within 8 focus groups. Results: Staff were very aware of common UTI symptoms and nitrofurantoin as first-line treatment, but some were less aware about when to send a urine culture, second-line and non-antibiotic management, and did not probe for signs and symptoms to specifically exclude vaginal causes or pyelonephritis before prescribing. Many consultations were undertaken over the phone, many by nurse practitioners, and followed established protocols that often included urine dipsticks and receptionists. Patient expectations increased use of urine dipsticks, and immediate and 5 days courses of antibiotics. Management decisions were also influenced by patient co-morbidities. No participants had undertaken recent UTI audits. Patient discussions around antibiotic resistance and back-up antibiotics were uncommon compared to consultations for respiratory infections. Conclusions: Knowledge and skill gaps could be addressed with education and clear, accessible, UTI diagnostic and management guidance and protocols that are also appropriate for phone consultations. Public antibiotic campaigns and patient-facing information should cover UTIs, non-pharmaceutical recommendations for "self-care", prevention and rationale for 3 days antibiotic courses. Practices should be encouraged to audit UTI management.

Point-of-Care Testing in Microbiology: A Mechanism for Improving Patient Outcomes

BACKGROUND

Increasingly, demands for improved health and quality of life conflict with the realities of delivering healthcare in an environment of higher expenditures, adherence to test utilization, and patient-centered experience. Patient-centered care is commonly identified as a goal of healthcare delivery, and yet healthcare systems struggle with delivery of care to patients, often failing to identify the seriously ill and capitalize on the predictive qualities of diagnostic testing. Point-of-care (POC) testing provides access to rapid diagnosis and predictive value key to realizing patient outcomes. An evaluation of cost-effective models and the clinical impact of POC testing for clinical microbiology is needed.

CONTENT

Accurate and rapid diagnostics have the potential to affect healthcare decisions to a degree well out of proportion to their cost. Contemporary healthcare models increasingly view POC testing as a mechanism for efficient deployment of healthcare. POC testing can deliver rapid diagnosis in environments where testing results can be used to direct management during patient visits and in areas where centralized laboratory testing may limit access to care. Nucleic acid assays, designed for POC testing, can match, or exceed, the sensitivity of conventional laboratory-based testing, eliminating the need for confirmation testing. Here, the goals of POC testing for microbiology, applications, and technologies, as well as outcomes and value propositions, are discussed.

SUMMARY

The combination of rapid reporting, an increasing array of organisms capable of causing disease, actionable resulting, and improved patient outcomes is key in the evolution of POC testing in clinical microbiology.

A new point-of-care test for the rapid detection of urinary tract infections

Urinary tract infections (UTIs) are among the most common infections in all age groups. Fast and accurate diagnosis is essential to ensure a timely and effective therapy. Alongside with reference culture-based methods, several point-of-care tests (POCTs) for early detection of UTIs have been developed, but they have not been significantly implemented in current clinical practice. The Micro Biological Survey (MBS) POCT is a simple test developed by MBS Diagnostics Ltd. (London, UK) for the detection and management of UTIs. The present study has been undertaken to investigate the potentials and limits of the MBS POCT. A total of 349 patients were enrolled in two open-label, monocentric, non-interventional clinical trials in collaboration with an Emergency Medicine department and the outpatient clinic of two hospitals in Rome. Results of urine analysis using the MBS POCT were compared with those of the routine culture-based tests for UTI diagnosis performed by the hospital laboratory. The MBS POCT provided fast results revealing high bacterial count UTIs (≥ 105 CFU/ml) with 97% accuracy, 92% sensitivity, 100% specificity, 99% PPV, and 96% NPV within a 5-h analytical time threshold.

Identification of clinical and urine biomarkers for uncomplicated urinary tract infection using machine learning algorithms

Women with uncomplicated urinary tract infection (UTI) symptoms are commonly treated with empirical antibiotics, resulting in overuse of antibiotics, which promotes antimicrobial resistance. Available diagnostic tools are either not cost-effective or diagnostically sub-optimal. Here, we identified clinical and urinary immunological predictors for UTI diagnosis. We explored 17 clinical and 42 immunological potential predictors for bacterial culture among women with uncomplicated UTI symptoms using random forest or support vector machine coupled with recursive feature elimination. Urine cloudiness was the best performing clinical predictor to rule out (negative likelihood ratio [LR−] = 0.4) and rule in (LR+ = 2.6) UTI. Using a more discriminatory scale to assess cloudiness (turbidity) increased the accuracy of UTI prediction further (LR+ = 4.4). Urinary levels of MMP9, NGAL, CXCL8 and IL-1β together had a higher LR+ (6.1) and similar LR− (0.4), compared to cloudiness. Varying the bacterial count thresholds for urine culture positivity did not alter best clinical predictor selection, but did affect the number of immunological predictors required for reaching an optimal prediction. We conclude that urine cloudiness is particularly helpful in ruling out negative UTI cases. The identified urinary biomarkers could be used to develop a point of care test for UTI but require further validation.

Exploiting open source 3D printer architecture for laboratory robotics to automate high-throughput time-lapse imaging for analytical microbiology

Growth in open-source hardware designs combined with the low-cost of high performance optoelectronic and robotics components has supported a resurgence of in-house custom lab equipment development. We describe a low cost (below $700), open-source, fully customizable high-throughput imaging system for analytical microbiology applications. The system comprises a Raspberry Pi camera mounted on an aluminium extrusion frame with 3D-printed joints controlled by an Arduino microcontroller running open-source Repetier Host Firmware. The camera position is controlled by simple G-code scripts supplied from a Raspberry Pi singleboard computer and allow customized time-lapse imaging of microdevices over a large imaging area. Open-source OctoPrint software allows remote access and control. This simple yet effective design allows high-throughput microbiology testing in multiple formats including formats for bacterial motility, colony growth, microtitre plates and microfluidic devices termed ‘lab-on-a-comb’ to screen the effects of different culture media components and antibiotics on bacterial growth. The open-source robot design allows customization of the size of the imaging area; the current design has an imaging area of ~420 × 300mm, which allows 29 ‘lab-on-a-comb’ devices to be imaged which is equivalent 3480 individual 1μl samples. The system can also be modified for fluorescence detection using LED and emission filters embedded on the PiCam for more sensitive detection of bacterial growth using fluorescent dyes.

Challenges in managing urinary tract infection and the potential of a point-of-care test guided care in primary care: an international qualitative study

BACKGROUND

Little is known about clinicians' experiences of using a point-of-care test (POCT) to inform management of urinary tract infection (UTI) in general practice.

AIM

To explore experiences of using the Flexicult test to inform management of UTI and views on requirements for an optimal POCT to inform successful implementation.

DESIGN & SETTING

Telephone interviews with 35 primary care clinicians and healthcare professionals in Wales, England, Spain, and the Netherlands, who had participated in a trial of the Flexicult POCT for UTI based on urine culture.

METHOD

Thematic analysis of semi-structured interviews.

RESULTS

Most primary care clinicians interviewed agreed on the need for a POCT in UTI management, and that the Flexicult POCT delivered quicker results than laboratory results used in usual care, reassured patients, boosted their confidence in decision-making, and reminded them about antibiotic stewardship. However, clinicians also reported difficulties in interpreting results, limitations on when the Flexicult could be used, and concerns that testing all patients would strain care delivery and prolong patient discomfort when delaying decisions until a non-rapid POCT result was available. An optimal POCT would produce more rapid results, and be reliable and easy to use. Uptake into routine care would be enhanced by: clear guidance on which patients should be tested; training for interpreting 'grey area' results; reiterating that even 'straightforward' cases might be better managed with a test; clear messages about stopping unnecessary antibiotics versus completing a course; and better self-management strategies to accompany implementation of delayed, or non-prescription of, antibiotics.

CONCLUSION

Primary care clinicians believe that POCT tests could play a useful role in the management of UTI and gave clear recommendations for successful implementation.