Comparison of Cepheid Xpert Flu/RSV XC and BioFire FilmArray for Detection of Influenza A, Influenza B, and Respiratory Syncytial Virus

Comparative analysis of RSV-related hospitalisations in children and adults over a 7 year-period before, during and after the COVID-19 pandemic

BACKGROUND

RSV is an important cause for respiratory illness in children and the elderly. We analysed RSV seasons since 2016 in both age groups for differences, similarities and timely associations before, during and after the COVID-19 pandemic.

METHODS

We studied epidemiological and clinical features of seven consecutive RSV seasons since 2016 retrospectively in children and adults who were systematically monitored for RSV infections by PCR when hospitalized in Regensburg, Germany.

RESULTS

Data from 1903 RSV positive, hospitalised patients were analysed (1446 children, 457 adults). We observed a complete absence of RSV associated hospitalizations in season 2020/2021. While in the season of 2021/2022, RSV associated hospitalizations in children returned to considerable numbers earlier than expected, hospitalizations in the elderly were still mitigated during that season in temporal association with the continuation of NPI measures for COVID-19 in the elderly until summer of 2022. Overall, children were hospitalized more often for RSV, while the elderly showed more severe outcomes. RSV hospitalisations continuously increase in both age groups, following a bi-annual pattern of severe and less severe seasons, which was not altered by the COVID-19 pandemic.

CONCLUSION

We demonstrate the relation between RSV waves in children and the elderly. NPI measures may protect the elderly from RSV infections and epidemiological data could be used to predict RSV waves early enough to prepare countermeasures.

Advanced Point-of-Care Testing Technologies for Human Acute Respiratory Virus Detection

The ever-growing global threats to human life caused by the human acute respiratory virus (RV) infections have cost billions of lives, created a significant economic burden, and shaped society for centuries. The timely response to emerging RVs could save human lives and reduce the medical care burden. The development of RV detection technologies is essential for potentially preventing RV pandemic and epidemics. However, commonly used detection technologies lack sensitivity, specificity, and speed, thus often failing to provide the rapid turnaround times. To address this problem, new technologies are devised to address the performance inadequacies of the traditional methods. These emerging technologies offer improvements in convenience, speed, flexibility, and portability of point-of-care test (POCT). Herein, recent developments in POCT are comprehensively reviewed for eight typical acute respiratory viruses. This review discusses the challenges and opportunities of various recognition and detection strategies and discusses these according to their detection principles, including nucleic acid amplification, optical POCT, electrochemistry, lateral flow assays, microfluidics, enzyme-linked immunosorbent assays, and microarrays. The importance of limits of detection, throughput, portability, and specificity when testing clinical samples in resource-limited settings is emphasized. Finally, the evaluation of commercial POCT kits for both essential RV diagnosis and clinical-oriented practices is included.

Current Status of Clinical Application of Point-of-Care Testing

CONTEXT.—

The clinical applications of point-of-care testing (POCT) are gradually increasing in many health care systems. Recently, POCT devices using molecular genetic method techniques have been developed. We need to examine clinical pathways to see where POCT can be applied to improve them.

OBJECTIVE.—

To introduce up-to-date POCT items and equipment and to provide the content that should be prepared for clinical application of POCT.

DATA SOURCES.—

Literature review based on PubMed searches containing the terms point-of-care testing, clinical chemistry, diagnostic hematology, and clinical microbiology.

CONCLUSIONS.—

If medical resources are limited, POCT can help clinicians make quick medical decisions. As POCT technology improves and menus expand, areas where POCT can be applied will also increase. We need to understand the limitations of POCT so that it can be optimally used to improve patient management.

Fluorescent and Opt-Electric Recording Bacterial Identification Device for Ultrasensitive and Specific Detection of Microbials

Since microbial detection is an important aspect for the prevention and control of foodborne diseases, an ideal detection system with high sensitivity, strong specificity, and timeliness is needed. Here, we proposed a fluorescent and opt-electric recording bacterial identification device (FORBID) for fully automatic real-time photoelectric sensing analysis of microbials by integrating the metabolic characteristics of microbial and selective substrate catalysis. It simplifies the testing process (one-step) and decreases the need of professional technicians. Besides, the system exhibits ultrasensitive (1 CFU/mL) and specific detection (99%) in both microbials, Escherichia coli and Pseudomonas aeruginosa. More importantly, the timeliness of this system is even better than that of the traditional culture methods. It is believed that this system can be extended to the detection of other microorganisms and provide a potential alternative for the detection of pathogens.

Multiplex Molecular Point-of-Care Test for Syndromic Infectious Diseases

Point-of-care (POC) molecular diagnostics for clinical microbiology and virology has primarily focused on the detection of a single pathogen. More recently, it has transitioned into a comprehensive syndromic approach that employs multiplex capabilities, including the simultaneous detection of two or more pathogens. Multiplex POC tests provide higher accuracy to for actionable decisionmaking in critical care, which leads to pathogen-specific treatment and standardized usages of antibiotics that help prevent unnecessary processes. In addition, these tests can be simple enough to operate at the primary care level and in remote settings where there is no laboratory infrastructure. This review focuses on state-of-the-art multiplexed molecular point-of-care tests (POCT) for infectious diseases and efforts to overcome their limitations, especially related to inadequate throughput for the identification of syndromic diseases. We also discuss promising and imperative clinical POC approaches, as well as the possible hurdles of their practical applications as front-line diagnostic tests.

Respiratory pathogen diversity and co-infections in rural Zambia

Objectives:

The role of respiratory co-infections in modulating disease severity remains understudied in southern Africa, particularly in rural areas. This study was performed to characterize the spectrum of respiratory pathogens in rural southern Zambia and the prognostic impact of co-infections.

Methods:

Respiratory specimens collected from inpatient and outpatient participants in a viral surveillance program in 2018–2019 were tested for selected viruses and a typical bacteria using the Xpert Xpress Flu/RSV assay and FilmArray Respiratory Panel EZ. Participants were followed for 3–5 weeks to assess their clinical course. Multivariable regression was used to examine the role of co-infections in influencing disease severity.

Results:

A respiratory pathogen was detected in 63.2% of samples from 671 participants who presented with influenza-like illness. Common pathogens identified included influenza virus (18.2% of samples), respiratory syncytial virus (RSV) (11.8%), rhinovirus (26.4%), and coronavirus (6.0%). Overall, 6.4% of participants were co-infected with multiple respiratory pathogens. Compared to mono-infections, co-infections were found not to be associated with severe clinical illness either overall (relative risk (RR) 0.72, 95% confidence interval (CI) 0.39–1.32) or specifically with influenza virus (RR 0.80, 95% CI 0.14–4.46) or RSV infections (RR 0.44, 95% CI 0.17–1.11).

Conclusions:

Respiratory infections in rural southern Zambia were associated with a wide range of viruses. Respiratory co-infections in this population were not associated with clinical severity.

Repeat Molecular Testing for Respiratory Pathogens: Diagnostic Gain or Diminishing Returns?

BACKGROUND

Upper respiratory tract infections are common, and the ability to accurately and rapidly diagnose the causative pathogen has important implications for patient management.

METHODS

We evaluated the test-ordering practices for 2 commonly utilized nucleic acid amplification tests (NAATs) for the detection of respiratory pathogens: the Xpert Flu Assay for influenza A/B (Flu assay) and the Biofire FilmArray respiratory panel assay (RP assay), which detects 20 different targets. Our study examined repeat testing; that is, testing within 7 days from an initial test.

RESULTS

Our study found that repeat testing is common for each of the individual assays: 3.0% of all Flu assays and 10.0% of all RP assays were repeat testing. Of repeat testing, 8/293 (2.7%) of repeat Flu assays and 75/1257 (6.0%) of RP assays resulted diagnostic gains, i.e., new detections. However, for the RP assay, these new detections were not always clinically actionable. The most frequently discrepant organisms were rhinovirus/enterovirus (28/102, 27.5%), followed by respiratory syncytial virus (12/102, 11.8%) and coronavirus OC43 (11/102, 10.8%). Furthermore, there were 3,336 instances in which a patient was tested using both a Flu assay and RP assay, of which only 44 (1.3%) had discrepant influenza results.

CONCLUSIONS

Our findings suggest opportunities exist to better guide ordering practices for respiratory pathogen testing, including limiting repeat testing, with the goal of optimization of clinical yield, and diagnostic stewardship.

Cepheid Xpert® Flu/RSV and Seegene Allplex™ RP1 show high diagnostic agreement for the detection of influenza A/B and respiratory syncytial viruses in clinical practice

Background

Molecular assays based on reverse transcription‐polymerase chain reaction (RT‐PCR) provide reliable results for the detection of respiratory pathogens, although diagnostic agreement varies. This study determined the agreement between the RT‐PCR assays (Xpert^® Flu/RSV vs Allplex^™ RP1) in detecting influenza A, influenza B, and respiratory syncytial viruses (RSVs) in clinical practice.

Methods

We retrospectively identified 914 patient encounters where testing with both Xpert^® Flu/RSV and Allplex^™ RP1 was undertaken between October 2015 and September 2019 in seven hospitals across New South Wales, Australia. The diagnostic agreement of the two assays was evaluated using positive percent agreement, negative percent agreement, and prevalence and bias‐adjusted kappa.

Results

The positive percent agreement was 95.1% for influenza A, 87.5% for influenza B, and 77.8% for RSV. The negative percent agreement was 99.4% for influenza A, 99.9% for influenza B, and 100% for RSV. The prevalence and bias‐adjusted kappa was 0.98 for influenza A, 0.99 for influenza B, and 0.97 for RSV. In a sensitivity analysis, the positive percent agreement values were significantly higher during the non‐influenza season than the influenza season for influenza B and RSV.

Conclusions

The Xpert^® Flu/RSV and Allplex^™ RP1 demonstrated a high diagnostic agreement for all three viruses assessed. The seasonal variation in the positive percent agreement of the two assays for influenza B and RSV may have been due to lower numbers assessed, variability in the virology of infections outside the peak season, or changes in the physiology of the infected host in different seasons.

Diagnostic and economic evaluation of a point-of-care test for respiratory syncytial virus

Respiratory syncytial virus is a common cause of bronchiolitis. Historically, point-of-care tests have involved antigen detection technology with limited sensitivity. The aim of this study was to prospectively evaluate the diagnostic accuracy and model the economic impact of the Roche cobas® Liat® point-of-care influenza A/B and respiratory syncytial virus test.

The “DEC-RSV” study was a multi-centre, prospective, observational study in children under 2 years presenting with viral respiratory symptoms. A nasopharyngeal aspirate sample was tested using the point-of-care test and standard laboratory-based procedures. The primary outcome was accuracy of respiratory syncytial virus detection. The cost implications of adopting a point-of-care test were modelled using study data.

A total of 186 participants were recruited, with both tests performed on 177 samples. The point-of-care test was invalid for 16 samples (diagnostic yield 91%) leaving 161 available for primary analysis. After resolving discrepancies, the cobas® Liat® respiratory syncytial virus test had 100.00% (95% CI 96.07%–100.00%) sensitivity and 98.53% (95% CI 92.08%–99.96%) specificity. Median time to result was 0.6 h (interquartile range (IQR) 0.5–1) for point-of-care testing and 28.9 h (IQR 26.3–48.1) for standard laboratory testing. Estimated non-diagnostic cost savings for 1000 patients, based on isolation decision-making on point-of-care test result, were £57 010, which would increase to £94 847 when cohort nursing is used.

In young children the cobas® Liat® point-of-care respiratory syncytial virus test has high diagnostic accuracy using nasopharyngeal aspirates (currently an off-licence sample type). Time to result is clinically important and was favourable compared to laboratory-based testing. The potential exists for cost savings when adopting the point-of-care test.

This prospective evaluation of the cobas Liat point-of-care RSV test in children demonstrated high diagnostic accuracy using nasopharyngeal aspirate samples, with favourable time to result compared to usual laboratory-based testing procedureshttps://bit.ly/2yKKmUB

A deep dive into testing and management of COVID-19 for Australian high performance and professional sport

The purpose of testing for any communicable disease is to support clinicians in the diagnosis and management of individual patients and to describe transmission dynamics. The novel coronavirus is formally named SARS-CoV-2 and the clinical disease state resulting from an infection is known as COVID-19. Control of the COVID-19 pandemic requires clinicians, epidemiologists, and public health officials to utilise the most comprehensive, accurate and timely information available to manage the rapidly evolving COVID-19 environment. High performance sport is a unique context that may look towards comprehensive testing as a means of risk mitigation. Characteristics of the common testing options are discussed including the circumstances where additional testing may be of benefit and considerations for the associated risks. Finally, a review of the available technology that could be considered for use by medical staff at the point of care (PoC) in a high-performance sporting context is included.

A Meta-Analysis of Multiple Whole Blood Gene Expression Data Unveils a Diagnostic Host-Response Transcript Signature for Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) is one of the major causes of acute lower respiratory tract infection worldwide. The absence of a commercial vaccine and the limited success of current therapeutic strategies against RSV make further research necessary. We used a multi-cohort analysis approach to investigate host transcriptomic biomarkers and shed further light on the molecular mechanism underlying RSV-host interactions. We meta-analyzed seven transcriptome microarray studies from the public Gene Expression Omnibus (GEO) repository containing a total of 922 samples, including RSV, healthy controls, coronaviruses, enteroviruses, influenzas, rhinoviruses, and coinfections, from both adult and pediatric patients. We identified > 1500 genes differentially expressed when comparing the transcriptomes of RSV-infected patients against healthy controls. Functional enrichment analysis showed several pathways significantly altered, including immunologic response mediated by RSV infection, pattern recognition receptors, cell cycle, and olfactory signaling. In addition, we identified a minimal 17-transcript host signature specific for RSV infection by comparing transcriptomic profiles against other respiratory viruses. These multi-genic signatures might help to investigate future drug targets against RSV infection.

Improvement in turnaround time for rapid respiratory virus testing using Xpert® Flu/RSV: a retrospective cohort study during a high incidence influenza season

Seasonal influenza like illness results in increased hospital presentations and unnecessary antibiotic use. Recent availability of rapid respiratory virus PCR testing allows rapid, accurate influenza diagnosis. A retrospective audit of turnaround time from sample collection to result availability after introduction of Xpert® Flu/RSV in a tertiary healthcare institution during a high incidence influenza season is described.

Comparative analysis of Four sample-to-answer influenza A/B and RSV nucleic acid amplification assays using adult respiratory specimens

BACKGROUND

The use of Sample-to-answer (STA) platforms for the detection of influenza A/B and respiratory syncytial virus (RSV) have greatly improved patient care. These diagnostic assays based on nucleic acid amplification are rapid, accurate and relatively easy to perform.

OBJECTIVES

We compared four such platforms for detecting FluA, FluB, and RSV from adult respiratory specimens: Hologic Panther Fusion® Flu A/B/RSV (Fusion), Cobas® Influenza A/B & RSV (Liat), Luminex Aries® Flu A/B & RSV (Aries), and Diasorin SimplexaTM Flu A/B & RSV (Simplexa).

STUDY DESIGN

Nasopharyngeal (NP) swabs (n = 224) from adults were tested on these platforms and results were compared to Center for Disease Control and Prevention recommended real-time RT-PCR assay for influenza A/B and RSV. Subtyping for FluA and FluB was performed for discrepant analysis where applicable.

RESULTS

Of the 82 FluA, 26 FluB, 15 RSV-positive specimens tested, the positive and negative percentage agreements (PPA and NPA respectively) for FluA detection were 100/100 (Fusion), 95.1/100 (Liat), 92.5/100 (Aries), and 84.1/99.3 (Simplexa); PPA and NPA for FluB detection were 92.3/99.5 (Fusion), 96/99.5 (Liat), 100/99.5 (Aries), and 80.8/100 (Simplexa); and for RSV detection were 100/100 (Fusion), 100/100 (Liat), 88.6/99.5 (Aries), and 73.3/100 (Simplexa). 82 confirmed FluA included 23 pH1N1 and 57 H3N2 strains with 2 strains remaining untyped. Of the 26 confirmed FluB, 25 were of the Yamagata lineage and 1 of unknown lineage.

CONCLUSION

Only 2 STA platforms demonstrated >95% PPA for the detection of all three targets while all the 4 platforms demonstrated >95% NPA for FluA, FluB and RSV.

Comparison of Six Sample-to-Answer Influenza A/B and Respiratory Syncytial Virus Nucleic Acid Amplification Assays Using Respiratory Specimens from Children

The rapid and accurate detection of influenza A virus (FluA), influenza B virus (FluB), and respiratory syncytial virus (RSV) improves patient care. Sample-to-answer (STA) platforms based on nucleic acid amplification and detection of these viruses are simple, automated, and accurate. We compared six such platforms for the detection of FluA, FluB, and RSV: Cepheid GeneXpert Xpress Flu/RSV (Xpert), Hologic Panther Fusion Flu A/B/RSV (Fusion), Cobas influenza A/B & RSV (Liat), Luminex Aries Flu A/B & RSV (Aries), BioFire FilmArray respiratory panel (RP), and Diasorin Simplexa Flu A/B & RSV (Simplexa). Nasopharyngeal (NP) swab specimens (n = 225) from children previously tested by RP were assessed on these platforms. The results were compared to those of the Centers for Disease Control and Prevention (CDC)-developed real-time reverse transcription-PCR (rRT-PCR) assay for influenza A/B viruses and RSV. Subtyping for FluA and FluB was performed for discrepant analysis where applicable. The percent sensitivities/specificities for FluA detection were 100/100 (Fusion), 98.6/99.3 (Xpert), 100/100 (Liat), 98.6/100 (Aries), 98.6/100 (Simplexa), and 100/100 (RP). The percent sensitivities/specificities for FluB detection were 100/100 (Fusion), 97.9/99.4 (Xpert), 97.9/98.3 (Liat), 93.7/99.4 (Aries), 85.4/99.4 (Simplexa), and 95.8/97.7 (RP); and those for RSV detection were 98.1/99.4 (Xpert), 98.1/99.4 (Liat), 96.3/100 (Fusion), 94.4/100 (Aries), 87/94.4 (Simplexa), and 94.4/100 (RP). The 75 strains confirmed to be FluA included 29 pH1N1, 39 H3N2, 4 sH1N1, and 3 untyped strains. The 48 strains confirmed to be FluB included 33 strains of the Yamagata lineage, 13 of the Victoria lineage, 1 of both the Yamagata and Victoria lineages, and 1 of an unknown lineage. All six STA platforms demonstrated >95% sensitivity for FluA detection, while three platforms (Fusion, Xpert, and Liat) demonstrated >95% sensitivity for FluB and RSV detection.

Rapid detection of respiratory organisms with the FilmArray respiratory panel in a large children's hospital in China

BACKGROUND

Respiratory tract infections (RTIs) are the most common illness in children, and rapid diagnosis is required for the optimal management of RTIs, especially severe infections.

METHODS

Nasopharyngeal swab or sputum specimens were collected from children aged 19 days to 15 years who were admitted to a hospital in Shanghai and diagnosed with RTIs. The specimens were tested with the FilmArray Respiratory Panel, a multiplex PCR assay that detects 16 viruses, Mycoplasma pneumoniae (M. pneumoniae), Bordetella pertussis (B. pertussis) and Chlamydophila pneumoniae (C. pneumoniae).

RESULTS

Among the 775 children studied, 626 (80.8%, 626/775) tested positive for at least one organism, and multiple organisms were detected in 198 (25.5%). Rhinoviruses/enteroviruses (25.5%, 198/775) were detected most often, followed by respiratory syncytial virus (19.5%, 151/775), parainfluenza virus 3 (14.8%, 115/775), influenza A or B (10.9%), adenovirus (10.8%), M. pneumoniae (10.6%) and B. pertussis (6.3%). The prevalence of organisms differed by age, and most of the viruses were more common in winter. Of the 140 children suspected of having pertussis, 35.0% (49/140) tested positive for B. pertussis.

CONCLUSIONS

FilmArray RP allows the rapid simultaneous detection of a wide number of respiratory organisms, with limited hands-on time, in Chinese pediatric patients with RTIs.

Systematic review of the impact of point-of-care testing for influenza on the outcomes of patients with acute respiratory tract infection

Acute respiratory tract infections are a major cause of morbidity and mortality and represent a significant burden on the health care system. Laboratory testing is required to definitively distinguish infecting influenza virus from other pathogens, resulting in prolonged emergency department (ED) visits and unnecessary antibiotic use. Recently available rapid point-of-care tests (POCT) may allow for appropriate use of antiviral and antibiotic treatments and decrease patient lengths of stay. We undertook a systematic review to assess the effect of POCT for influenza on three outcomes: (1) antiviral prescription, (2) antibiotic prescription, and (3) patient length of stay in the ED. The databases Medline and Embase were searched using MeSH terms and keywords for influenza, POCT, antivirals, antibiotics, and length of stay. Amongst 245 studies screened, 30 were included. The majority of papers reporting on antiviral prescription found that a positive POCT result significantly increased use of antivirals for influenza compared with negative POCT results and standard supportive care. A positive POCT result also led to decreased antibiotic use. The results of studies assessing the effect of POCT on ED length of stay were not definitive. The studies assessed in this systematic review support the use of POCT for diagnosis of influenza in patients suffering an acute respiratory infection. Diagnosis using POCT may lead to more appropriate prescription of treatments for infectious agents. Further studies are needed to assess the effect of POCT on the length of stay in ED.

Evaluation of FilmArray respiratory panel multiplex polymerase chain reaction assay for detection of pathogens in adult outpatients with acute respiratory tract infection

Although viruses are the major pathogen that causes upper respiratory tract infection (URTI) and acute bronchitis, antibiotics have been prescribed. This was a prospective observational study in influenza epidemics that enrolled adult outpatients who visited a hospital with respiratory tract infection symptoms. In this study, we evaluated the usefulness of FilmArray respiratory panel (RP). Fifty patients were enrolled. FilmArray RP detected the pathogens in 28 patients. The common pathogens were influenza virus (n = 14), respiratory syncytial virus (n = 6), and human rhinovirus (n = 6). Of the 14 patients with influenza virus, 6 were negative for the antigen test. The physicians diagnosed and treated the patients without the result of FilmArray in this study. Of the patients with positive FilmArray RP, 9 were treated with antibiotics; however, bacteria were detected in only 3 patients. By implementing FilmArray RP, URTI and acute bronchitis would be precisely diagnosed, and inappropriate use of antibiotics can be reduced.

Profile of the Alere i Influenza A & B assay: a pioneering molecular point-of-care test

INTRODUCTION

The Alere i Influenza A & B assay incorporates the Nicking Enzyme Amplification Reaction technique on the Alere i instrument to detect and differentiate influenza virus (Flu) A and B nucleic acids in specific specimens. Areas covered: The Alere i Influenza A & B assay was cleared by the US Food and Drug Administration for use with nasal swabs (NS) and nasopharyngeal swabs, either directly or in viral transport medium. Notably, direct use on NS was the first ever CLIA-waived nucleic acid-based test. Previously published evaluations have reported sensitivities and specificities of 55.2-100% and 62.5-100% for Flu A and 45.2-100% and 53.6-100% for Flu B, respectively. Expert commentary: The Alere i Influenza A & B assay provides a rapid and simple platform for detection and differentiation of Flu A and B. Efforts are expected to further improve sensitivity and user-friendliness for effective and widespread use in the true point-of-care setting.

A Multifunctional Reactor with Dry-Stored Reagents for Enzymatic Amplification of Nucleic Acids

To enable inexpensive molecular detection at the point-of-care and at home with minimal or no instrumentation, it is necessary to streamline unit operations and store reagents refrigeration-free. To address this need, a multifunctional enzymatic amplification reactor that combines solid-phase nucleic acid extraction, concentration, and purification; refrigeration-free storage of reagents with just-in-time release; and enzymatic amplification is designed, prototyped, and tested. A nucleic acid isolation membrane is placed at the reactor's inlet, and paraffin-encapsulated reagents are prestored within the reactor. When a sample mixed with chaotropic agents is filtered through the nucleic acid isolation membrane, the membrane binds nucleic acids from the sample. Importantly, the sample volume is decoupled from the reaction volume, enabling the use of relatively large sample volumes for high sensitivity. When the amplification reactor's temperature increases to its operating level, the paraffin encapsulating the reagents melts and moves out of the way. The reagents are hydrated, just-in-time, and the polymerase reaction proceeds. The amplification process can be monitored, in real-time. We demonstrate our reactors' ability to amplify both DNA and RNA targets using polymerase with both reverse-transcriptase and strand displacement activities to obtain sensitivities on-par with benchtop equipment and a shelf life exceeding 6 months.

Performance of the Alere i RSV assay for point-of-care detection of respiratory syncytial virus in children

BACKGROUND

Respiratory syncytial virus (RSV) is the most important cause of severe acute respiratory tract infection in young children. Alere i RSV is a novel molecular rapid test which identifies respiratory syncytial virus in less than 13 min.

METHODS

We evaluated the clinical performance of the Alere i RSV assay in a pediatric point-of-care setting during winter season 2016 / 2017. Test results from 518 nasopharyngeal swab samples were compared to a real-time reverse transcription PCR reference standard.

RESULTS

The overall sensitivity and specificity of the Alere i RSV test assay was 93% (CI⁹⁵ 89% - 96%) and 96% (CI⁹⁵ 93% - 98%), respectively. Alere i RSV performed well in children of all age groups. An optimal sensitivity of 98% (CI⁹⁵ 94% - 100%) and specificity of 96% (CI⁹⁵ 90% - 99%) was obtained in children < 6 months. In children ≥ 2 years, sensitivity and specificity remained at 87% (CI⁹⁵ 73% - 96%) and 98% (CI⁹⁵ 92% - 100%), respectively. False negative Alere i RSV test results mostly occurred in samples with low viral load (mean CT value 31.1; CI⁹⁵ 29.6 - 32.6). The Alere i RSV assay is easy to use and can be operated after minimal initial training. Test results are available within 13 min, with most RSV positive samples being identified after approximately 5 min.

CONCLUSION

The Alere i RSV assay has the potential to facilitate the detection of RSV in pediatric point-of-care settings.

Evaluation of the molecular Xpert Xpress Flu/RSV assay vs. Alere i Influenza A & B assay for rapid detection of influenza viruses

A new FDA-approved Xpert Xpress Flu/RSV assay has been released for rapid influenza virus detection. We collected 134 nasopharyngeal specimens to compare the diagnostic performance of the Xpert assay and the Alere i Influenza A & B assay for influenza A and B virus detection. The Xpert assay demonstrated 100% and 96.3% sensitivity to influenza A and influenza B virus respectively. Its specificity was 100% for both viruses. The Alere i assay demonstrated slightly lower sensitivity but similar specificity to the Xpert Xpress assay. Although the Xpert assay (30 min) required longer processing time than the Alere assay (15 min), the handling procedure of the Alere assay was more complicated than the Xpert assay. As the GenXpert system has higher throughput than the Alere system, it is more suitable for hospital clinical laboratories. Overall, the new Xpert Xpress Flu/RSV assay is a reliable and useful tool for rapid influenza detection.

The performance of Luminex ARIES® Flu A/B & RSV and Cepheid Xpert® Flu/RSV XC for the detection of influenza A, influenza B, and respiratory syncytial virus in prospective patient samples

BACKGROUND

The demand for rapid, accurate viral testing has increased the number of assays available for the detection of viral pathogens. One of the newest FDA cleared platforms is the Luminex ARIES^® Flu A/B & RSV, which is a fully automated, real-time PCR-based assay used for detection of influenza A, influenza B, and respiratory syncytial virus (RSV).

OBJECTIVES

We sought to compare the performance of Luminex ARIES^® Flu A/B & RSV assay to the Cepheid Xpert^® Flu/RSV XC assay for rapid Flu and RSV testing.

STUDY DESIGN

A series of consecutive nasopharyngeal specimens received in the clinical microbiology laboratory during peak influenza season at a major academic center in Chicago, IL, were prospectively tested, using both the ARIES^® Flu A/B & RSV and Xpert^® Flu/RSV XC assays, side by side. Discrepant results were tested on the BioFire FilmArray^® Respiratory Panel for resolution.

RESULTS

A total of 143 consecutive nasopharyngeal specimens, obtained from patients ranging from six months to ninety-three years in age were received between January 1st, 2017 and March 21st, 2017. There was 96.6% agreement between the two assays for detection influenza A, 100% agreement for detection influenza B and RSV, and 98.9% agreement for negative results. The Xpert^® Flu/RSV XC performed with an average turn-around time of approximately 60min, compared to the ARIES^® Flu A/B & RSV of approximately 120min. Both assays were equally easy to perform, with a similar amount of hands-on technologist time for each platform.

CONCLUSIONS

Overall, these results indicate that both tests are comparable in terms of result agreement and technical ease-of-use. The Xpert^® Flu/RSV XC assay did produce results with less turn-around-time, approximately 60min quicker than the ARIES^® Flu A/B & RSV.

Reducing Uncertainty for Acute Febrile Illness in Resource-Limited Settings: The Current Diagnostic Landscape

AbstractDiagnosing the cause of acute febrile illness in resource-limited settings is important-to give the correct antimicrobials to patients who need them, to prevent unnecessary antimicrobial use, to detect emerging infectious diseases early, and to guide vaccine deployment. A variety of approaches are yielding more rapid and accurate tests that can detect more pathogens in a wider variety of settings. After decades of slow progress in diagnostics for acute febrile illness in resource-limited settings, a wave of converging advancements will enable clinicians in resource-limited settings to reduce uncertainty for the diagnosis of acute febrile illness.

Reverse-transcription loop-mediated isothermal amplification for rapid detection of respiratory syncytial virus directly from nasopharyngeal swabs

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in young infants and a major cause of nosocomial infection in pediatric care. Currently available RSV point-of-care tests are of limited sensitivity and relatively expensive. We developed and evaluated a novel RSV rapid test for use at point-of-care, based on reverse-transcription loop-mediated isothermal amplification (RT-LAMP) for direct testing of nasopharyngeal swab specimens. RT-LAMP can detect RSV within 30min, without the need for RNA extraction. The sensitivity of our RT-LAMP assay was 70-80% in comparison to RT-PCR. The RT-LAMP test sensitivity is at least equivalent to currently available rapid antigen detection tests (RADT), and the cost of RT-LAMP test reagents is only approximately 10% of that of commercially available RADT tests. RT-LAMP appears to be an attractive alternative to RADT, particularly in settings with limited financial resources. Future improvements could include lyophilization of test reagents and automated read-out of RT-LAMP results.

Evaluation of Alere i RSV for Rapid Detection of Respiratory Syncytial Virus in Children Hospitalized with Acute Respiratory Tract Infection

Alere i RSV is a novel rapid test which applies a nicking enzyme amplification reaction to detect respiratory syncytial virus in point-of-care settings. In this study, we evaluated the Alere i RSV assay by using frozen nasopharyngeal swab samples that were collected in viral transport medium from children hospitalized with acute respiratory tract infection during the 2015-2016 winter season. Alere i RSV assay results were compared to those for Altona RealStar RSV real-time reverse transcription-PCR (RT-PCR). We found that the overall sensitivity and specificity of the Alere i RSV test was 100% (95% confidence intervals [CI], 93% to 100%) and 97% (95% CI, 89% to 100%), respectively. Positive samples were identified within 5 to 7 min from sample collection. Overall, the Alere i RSV test performed well compared to the RT-PCR assay and has the potential to facilitate the detection of RSV in point-of-care settings.