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

Burden of RSV infections among young children in primary care: a prospective cohort study in five European countries (2021-23)

BACKGROUND

The majority of respiratory syncytial virus (RSV) infections in young children are managed in primary care, however, the disease burden in this setting remains poorly defined.

METHODS

We did a prospective cohort study in primary care settings in Belgium, Italy, Spain, the Netherlands, and the UK during the RSV seasons of 2020-21 (UK only; from Jan 1, 2021), 2021-22, and 2022-23. Children aged younger than 5 years presenting to their general practitioner or primary care paediatrician with symptoms of an acute respiratory tract infection were eligible for RSV testing. Children who tested positive for RSV were consented and followed up for 30 days via a physician clinical report (initial primary care visit on day 1) and two parent-report questionnaires (days 14 and 30). We assessed the burden of RSV in terms of clinical course (symptoms, illness duration, and complications), health-care resource utilisation (primary care visits, emergency department visits, hospitalisation rate, and medication use), and societal impact (daycare or school absence and parental work absence) for the 30-day follow-up period.

FINDINGS

Among 3414 tested children, 1124 (32·9%; 95% CI 31·3-34·5) tested positive for RSV. Among children with data on age, RSV positivity rate was 38·9% (36·1-41·7; n=466 of 1198) in children younger than 1 year and 25·9% (24·0-27·9; n=513 of 1979) in those aged 1 to <5 years. Of the 1124 RSV-positive children, 878 (78·1%) were enrolled and had day 1 data collected (median age 11·1 months [IQR 6·0-22·0]; 446 [50·9%] boys and 431 [49·1%] girls [N=877]). RSV illness lasted a mean of 11·7 days (95% CI 11·2-12·2; n=794). At day 14 and day 30, any remaining symptoms were reported in 451 of 804 (56·1% [95% CI 52·6-59·6]) and 261 of 724 (36·0% [32·6-39·7]) children. The mean number of primary care visits per child ranged from 1·4 (95% CI 1·2-1·6; the Netherlands) to 3·0 (2·8-3·3; Spain), and was higher in children younger than 1 year (2·7 visits [2·4-2·9]) than in those aged 1 to <5 years (2·1 [1·9-2·2]). Prescribed medication use varied, from 25 of 96 children (26·0% [95% CI 17·6-36·0]; the UK) to 228 of 297 children (76·8% [71·5-81·5]; Italy), with bronchodilators and antibiotics being the most commonly prescribed medicines across all countries. Prescribed medication use was reported in 258 of 418 children aged 1 to <5 years (61·7% [56·9-66·4]) and 196 of 394 children younger than 1 year (49·7% [44·7-54·8]). Missed working days by parents due to their child's RSV illness were reported in 340 of 744 cases (45·7% [42·1-49·4]); the mean number of missed workdays ranged from 1·3 days (95% CI 0·5-2·2) in Spain to 4·1 days (3·3-5·0) in Belgium.

INTERPRETATION

RSV infections in children younger than 5 years in primary care are associated with substantial symptomatology, health-care utilisation, and parental work absence. Notable differences in RSV burden existed across countries, likely due to differences in primary health-care systems, clinical practice, and health-care-seeking behaviour. This study emphasises the importance of considering country-specific primary care burden estimates when considering the implementation of RSV immunisations programmes.

FUNDING

Sanofi and AstraZeneca.

At-home testing for respiratory viruses: a minireview of the current landscape

The landscape of at-home testing using over-the-counter (OTC) tests has been evolving over the last decade. The United States Food and Drug Administration Emergency Use Authorization rule has been in effect since the early 2000s, and it was widely employed during the severe acute respiratory syndrome coronavirus 2 pandemic to authorize antigen and nucleic acid detection tests for use in central laboratories as well as OTC. During the pandemic, the first at-home tests for respiratory viruses became available for consumer use, which opened the door for additional respiratory virus OTC tests. Concerns may exist regarding the public's ability to properly collect samples, perform testing, interpret results, and report results to public health authorities. However, favorable comparison studies between OTC testing and centralized laboratory test results suggest that OTC testing may have a place in healthcare, and it is likely here to stay. This mini-review of OTC tests for viral respiratory diseases will briefly cover the regulatory and reimbursement environment, current OTC test availability, as well as the advantages and limitations of OTC tests.

Summarizing Study Characteristics and Diagnostic Performance of Commercially Available Tests for Respiratory Syncytial Virus: A Scoping Literature Review in the COVID-19 Era

BACKGROUND

Nonpharmaceutical interventions to prevent the spread of coronavirus disease 2019 also decreased the spread of respiratory syncytial virus (RSV) and influenza. Viral diagnostic testing in patients with respiratory tract infections (RTI) is a necessary tool for patient management; therefore, sensitive and specific tests are required. This scoping literature review aimed to summarize the study characteristics of commercially available sample-to-answer RSV tests.

CONTENT

PubMed and Embase were queried for studies reporting on the diagnostic performance of tests for RSV in patients with RTI (published January 2005-January 2021). Information on study design, patient and setting characteristics, and published diagnostic performance of RSV tests were extracted from 77 studies that met predefined inclusion criteria. A literature gap was identified for studies of RSV tests conducted in adult-only populations (5.3% of total subrecords) and in outpatient (7.5%) or household (0.8%) settings. Overall, RSV tests with analytical time >30 min had higher published sensitivity (62.5%-100%) vs RSV tests with analytical time ≤30 min (25.7%-100%); this sensitivity range could be partially attributed to the different modalities (antigen vs molecular) used. Molecular-based rapid RSV tests had higher published sensitivity (66.7%-100%) and specificity (94.3%-100%) than antigen-based RSV tests (sensitivity: 25.7%-100%; specificity:80.3%-100%).

SUMMARY

This scoping review reveals a paucity of literature on studies of RSV tests in specific populations and settings, highlighting the need for further assessments. Considering the implications of these results in the current pandemic landscape, the authors preliminarily suggest adopting molecular-based RSV tests for first-line use in these settings.

Describing global pediatric RSV disease at intensive care units in GAVI-eligible countries using molecular point-of-care diagnostics: the RSV GOLD-III study protocol

Background

Respiratory syncytial virus (RSV) infection is an important cause of hospitalization and death in young children. The majority of deaths (99%) occur in low- and lower-middle-income countries (LMICs). Vaccines against RSV infection are underway. To obtain access to RSV interventions, LMICs depend on support from Gavi, the Vaccine Alliance. To identify future vaccine target populations, information on children with severe RSV infection is required. However, there is a lack of individual patient-level clinical data on instances of life-threatening RSV infection in LMICs. The RSV GOLD III—ICU Network study aims to describe clinical, demographic and socioeconomic characteristics of children with life-threatening RSV infection in Gavi-eligible countries.

Methods

The RSV GOLD-III—ICU Network study is an international, prospective, observational multicenter study and will be conducted in 10 Gavi-eligible countries at pediatric intensive care units and high-dependency units (PICUs/HDUs) during local viral respiratory seasons for 2 years. Children younger than 2 years of age with respiratory symptoms fulfilling the World Health Organization (WHO) “extended severe acute respiratory infection (SARI)” case definition will be tested for RSV using a molecular point-of-care (POC) diagnostic device. Patient characteristics will be collected through a questionnaire. Mortality rates of children admitted to the PICU and/or HDU will be calculated.

Discussion

This multicenter descriptive study will provide a better understanding of the characteristics and mortality rates of children younger than 2 years with RSV infection admitted to the PICU/HDU in LMICs. These results will contribute to knowledge on global disease burden and awareness of RSV and will directly guide decision makers in their efforts to implement future RSV prevention strategies.

Trial registration number: NL9519, May 27, 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06544-3.

Low Sensitivity of BinaxNOW RSV in Infants

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of hospitalization in infants. Early detection of RSV can optimize clinical management and minimize use of antibiotics. BinaxNOW RSV (BN) is a rapid antigen detection test that is widely used. We aimed to validate the sensitivity of BN in hospitalized and nonhospitalized infants against the gold standard of molecular diagnosis.

METHODS

We evaluated the performance of BN in infants with acute respiratory tract infections with different degrees of disease severity. Diagnostic accuracy of BN test results were compared with molecular diagnosis as reference standard.

RESULTS

One hundred sixty-two respiratory samples from 148 children from October 2017 to February 2019 were studied. Sixty-six (40.7%) samples tested positive for RSV (30 hospitalizations, 31 medically attended episodes not requiring hospitalization, and 5 nonmedically attended episodes). Five of these samples tested positive with BN, leading to an overall sensitivity of BN of 7.6% (95% confidence interval [CI], 3.3%-16.5%) and a specificity of 100% (95% CI, 96.2%-100%). Sensitivity was low in all subgroups.

CONCLUSIONS

We found a low sensitivity of BN for point-of-care detection of RSV infection. BinaxNOW RSV should be used and interpreted with caution.

Group B Streptococcus Meningitis in an Infant with Respiratory Syncytial Virus Detection

We report our experience caring for an infant with respiratory syncytial virus infection (RSV) and group B Streptococcus (GBS) bacteremia and meningitis. Concurrent GBS meningitis and RSV is rare but highlights the importance of correlating clinical symptoms with viral diagnostic testing during the evaluation of infants at risk for serious bacterial infection.

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

Evaluation of a commercial latex agglutination test for detecting rotavirus A and human adenovirus in children's stool specimens

Objectives

Rotavirus A and human adenovirus are the two most common causes of infantile diarrhea; thus, it is of great importance to find out a rapid and accurate diagnostic method. This study aimed to evaluate the diagnostic significance of latex agglutination test for detection of rotavirus A and human adenovirus.

Methods

A prospective study was conducted on 214 diarrhea children from September 2018 to March 2019 in our hospital. Fresh stool samples were collected for detection of rotavirus A and human adenovirus by latex agglutination test and quantitative reverse transcription polymerase chain reaction (RT‐qPCR). Then, the consistency of results detected by these two methods was analyzed．

Results

With performing the latex agglutination test, it was revealed that positive rates for detecting rotavirus A virus and human adenovirus were 23.83% (51/214) and 25.24% (54/214), respectively. Meanwhile, results of RT‐qPCR showed that positive rates for detecting rotavirus A virus and human adenovirus were 58 (27.10%) and 59 (27.57%), respectively. Using RT‐qPCR as the gold standard, the sensitivity and specificity of the latex agglutination test for detecting rotavirus A were 81.03% and 97.44%, and the corresponding values for detecting human adenovirus were 76.27% and 94.19%, respectively.

Conclusion

This latex agglutination test showed a satisfactory consistency with RT‐qPCR for detecting rotavirus A and human adenovirus. The mentioned commercial assay may be highly appropriate for rapid screening of rotavirus A and human adenovirus.

Developmental roadmap for antimicrobial susceptibility testing systems

Antimicrobial susceptibility testing (AST) technologies help to accelerate the initiation of targeted antimicrobial therapy for patients with infections and could potentially extend the lifespan of current narrow-spectrum antimicrobials. Although conceptually new and rapid AST technologies have been described, including new phenotyping methods, digital imaging and genomic approaches, there is no single major, or broadly accepted, technological breakthrough that leads the field of rapid AST platform development. This might be owing to several barriers that prevent the timely development and implementation of novel and rapid AST platforms in health-care settings. In this Consensus Statement, we explore such barriers, which include the utility of new methods, the complex process of validating new technology against reference methods beyond the proof-of-concept phase, the legal and regulatory landscapes, costs, the uptake of new tools, reagent stability, optimization of target product profiles, difficulties conducting clinical trials and issues relating to quality and quality control, and present possible solutions.

This Consensus Statement presents the barriers that currently prevent the timely development and implementation of novel and rapid antimicrobial susceptibility testing platforms, including the costs involved, uptake of new tools, legal and regulatory aspects, difficulties conducting clinical trials and quality control, and presents possible solutions.

RSVpredict: An Online Tool to Calculate the Likelihood of Respiratory Syncytial Virus Infection in Children Hospitalized With Acute Respiratory Disease

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in young children. Early detection of RSV infection can avoid unnecessary diagnostic and therapeutic intervention and is required to prevent the nosocomial spread of RSV infection in pediatric hospitals. We developed a web tool to calculate the probability of RSV infection in children hospitalized with acute respiratory tract infection (ARTI) (RSVpredict).

METHODS

During winter seasons 2014/2015 to 2017/2018, 1545 children hospitalized with clinical symptoms of ARTI at the University Hospital Heidelberg/Germany were prospectively included. Medical information was reported on a standardized data sheet, and nasopharyngeal swabs were obtained for multiplex real-time polymerase chain reaction analyses. We applied logistic regression to develop a prediction model and developed a web-based application to predict the individual probability of RSV infection.

RESULTS

Duration of clinical symptoms ≥2 days on admission, calendar month of admission, admission for lower respiratory tract infection, the presence of cough and rale and younger age were associated with RSV infection (P < 0.05). Those data were included in the prediction model (RSVpredict, https://web.imbi.uni-heidelberg.de/rsv/). RSVpredict is a web-based application to calculate the risk of RSV infection in children hospitalized with ARTI. The prediction model is based on easily accessible clinical symptoms and predicts the individual probability of RSV infection risk immediately.

CONCLUSIONS

Pediatricians might use the RSVpredict to take informed decisions on further diagnostic and therapeutic intervention, including targeted RSV testing in children with relevant RSV infection risk.

Development of a Rapid Fluorescent Immunochromatographic Test to Detect Respiratory Syncytial Virus

Human respiratory syncytial virus (RSV) is one of the most common viruses infecting the respiratory tracts of infants. The rapid and sensitive detection of RSV is important to minimize the incidence of infection. In this study, novel monoclonal antibodies (mAbs; B11A5 and E8A11) against RSV nucleoprotein (NP) were developed and applied to develop a rapid fluorescent immunochromatographic strip test (FICT), employing europium nanoparticles as the fluorescent material. For the FICT, the limits of detection of the antigen and virus were 1.25 µg/mL and 4.23 × 10⁶ TCID₅₀/mL, respectively, corresponding to 4.75 × 10⁶ ± 5.8 ×10⁵ (mean ± SD) RNA copy numbers per reaction mixture for RSV NP. A clinical study revealed a sensitivity of 90% (18/20) and specificity of 98.18% (108/110) for RSV detection when comparing the performance to that of reverse transcription polymerase chain reaction (RT-PCR), representing a 15% improvement in sensitivity over the SD Bioline rapid kit. This newly developed FICT could be a useful tool for the rapid diagnosis of RSV infection.

Rapid and simple molecular tests for the detection of respiratory syncytial virus: a review

INTRODUCTION

Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infections. The clinical manifestations of RSV are indistinguishable from other etiologies of acute respiratory infection. Therefore, accurate and timely laboratory testing is needed to impact clinical management. There are now multiple rapid, low-complexity, commercially available assays for RSV. These tests present significant performance advantages compared to older antigen detection tests. Accurate and rapid diagnosis of RSV has the potential for enabling timely cessation of unnecessary antibiotics and implementation of good infection control practices. Furthermore, a recently approved RSV diagnostic assay can reduce the test turnaround time to 13 min or less. Areas covered: The authors aim to review the importance of rapid and accurate testing for RSV and will describe the available molecular RSV diagnostic assays approved for use at the point-of-care. Expert commentary: Further independent evaluations are needed to confirm that the accuracy of the low-complexity assays is indeed similar to reverse transcriptase polymerase chain reaction across the age spectrum, and in immunosuppressed hosts. In the future, the challenge will be to achieve a balance between increasingly sophisticated multiplex diagnostic platforms and tests that are sufficiently simple to be used at the point-of-care.

Detection of Influenza A and B Viruses and Respiratory Syncytial Virus by Use of Clinical Laboratory Improvement Amendments of 1988 (CLIA)-Waived Point-of-Care Assays: a Paradigm Shift to Molecular Tests

An accurate laboratory diagnosis of influenza, respiratory syncytial virus (RSV), and other respiratory viruses can help to guide patient management, antiviral therapy, infection prevention strategies, and epidemiologic monitoring. Influenza has been the primary driver of rapid laboratory testing due to its morbidity and mortality across all ages, the availability of antiviral therapy, which must be given early to have an effect, and the constant threat of new pandemic strains. Over the past 30 years, there has been an evolution in viral diagnostic testing, from viral culture to rapid antigen detection, and more recently, to highly sensitive nucleic acid amplification tests (NAAT), as well as a trend to testing at the point of care (POC). Simple rapid antigen immunoassays have long been the mainstay for POC testing for influenza A and B viruses and respiratory syncytial virus (RSV) but have been faulted for low sensitivity. In 2015, the first POC NAAT for the detection of influenza was approved by the Food and Drug Administration (FDA), ushering in a new era. In 2017, the FDA reclassified rapid influenza diagnostic tests (RIDTs) from class I to class II devices with new minimum performance standards and a requirement for annual reactivity testing. Consequently, many previously available RIDTs can no longer be purchased in the United States. In this review, recent developments in Clinical Laboratory Improvement Amendments of 1988 (CLIA)-waived testing for respiratory virus infections will be presented, with the focus on currently available FDA-cleared rapid antigen and molecular tests primarily for influenza A and B viruses and RSV.

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.

Clinical evaluation of a novel and simple-to-use molecular platform for diagnosis of respiratory syncytial virus

Rapid molecular diagnostic testing for respiratory infections can improve patient care and minimize unnecessary prescriptions of antibiotics. We present the preliminary clinical evaluation of Orion GenRead^® RSV, a novel, rapid, and easy-to-use molecular test for the diagnosis of respiratory syncytial virus (RSV) infection. The sensitivity and specificity of Orion GenRead RSV were 99% and 100%, respectively. Orion GenRead RSV detected RSV-positive specimens within 15 min. The performance of Orion GenRead RSV was similar to that of the reference method and this test could rapidly detect RSV within minutes. Orion GenRead RSV is applicable for near-patient testing.