Comparison of the Luminex xTAG Respiratory Viral Panel Fast v2 Assay With Anyplex II RV16 Detection Kit and AdvanSure RV Real-Time RT-PCR Assay for the Detection of Respiratory Viruses

Respiratory Adenovirus Quantification with a Droplet Digital Polymerase Chain Reaction (ddPCR) Assay

Human adenoviruses (HAdVs) are double-stranded DNA viruses that can cause a wide spectrum of disease, including respiratory infections. Little is known about the value of respiratory HAdV quantification and its correlation with disease severity. In this study, we developed a quantitative HAdV droplet digital PCR (ddPCR) assay to study the association between viral loads, circulating types, and clinical outcomes. Remnant respiratory specimens positive for HAdV after the standard of care testing were collected from December 2020 to April 2022. A total of 129 samples were tested by a ddPCR method. Typing was performed using Nanopore sequencing of the hexon gene hypervariable region. Clinical chart reviews were performed to correlate the viral loads with the disease severity. The ddPCR assay showed an analytical sensitivity and a lower limit of quantification below 100 copies/mL. Of 129 positive clinical samples, 100 were quantified by ddPCR, 7 were too concentrated to be quantified, and 22 were negative. Of the 22 false negatives, only 3 were successfully typed; however, 99 of the 107 positive samples had a characterized genotype. The main HAdV types identified in this cohort were C1 (49.5%) followed by C2 (34.3%). No significant difference in HAdV loads was noted between patients who were admitted, those who required supplemental oxygen, and outpatients or between different HAdV types. HAdV ddPCR is a reliable absolute quantification approach for HAdV from respiratory samples. HAdV loads at initial presentation does not appear to differ between patients who require hospitalization versus outpatients. IMPORTANCE Measuring viral load using droplet digital PCR (ddPCR) is an absolute quantification approach that can facilitate comparability between different laboratories. This approach could prove valuable in studies that focus on the clinical utility of quantification. In this study, we evaluate a human adenovirus (HAdV) ddPCR assay and study the relationship between viral loads and outcomes after HAdV respiratory infections.

Development of a multiplexed Luminex assay for simultaneous detection of enteric viruses in cattle

Viral and bacterial gastroenteritis and diarrhea have long been a problem in livestock with devastating effects on animal health and production causing a heavy financial burden on producers. Therefore, the bead-based multiplex detection assay was created for simultaneous detection of three livestock viral diarrheic agents viz. bovine rotavirus (BRV), bovine coronavirus (BCoV) and bluetongue virus (BTV). The primers and probes for triplex MAGPIX assay for simultaneous detection of three enteric viruses were designed and the assay was optimized for hybridization temperature, primer-probe and bead concentrations. The newly developed MAGPIX assay was used to determine the prevalence of these diarrhea-associated viruses by testing 200 fecal samples collected from Haryana state of India during 2018-2019. The limit of detection of the developed triplex assay was 1 × 105, 1 × 104, and 1 × 105 RNA copies for BRV, BCoV, and BTV, respectively, being lower than the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). However, it was higher than the conventional RT-PCR, showing it to be more sensitive. The newly developed MAGPIX assay was a rapid, cost-effective and high throughput diagnostic tool for identification of three major entero-pathogenic diarrhea associated viruses, either alone or in tandem, with the aim to prevent and control viral diarrhea in animals.

Meta-Analysis of the Diagnostic Efficacy of the Luminex xTAG Respiratory Viral Panel FAST v2 Assay for Respiratory Viral Infections

PURPOSE

Acute respiratory viral infections pose significant morbidity and mortality, making it essential to diagnose respiratory viral infections rapidly. In this study, the diagnostic efficacy of the Luminex xTAG Respiratory Virus Panel (RVP) FAST v2 test was evaluated on respiratory viral infections.

MATERIALS AND METHODS

Information was retrieved from electronic databases, including Embase, Web of Science, PubMed, and Cochrane Library, for systematic review. Studies that fulfilled predefined inclusion criteria were included. After the extraction of information, statistical software was utilized for quality evaluation, data analysis, and assessment of publication bias.

RESULTS

Eighty groups in fourfold tables from nine articles were included to perform statistical analyses. Therein, the mean specificity and mean sensitivity of Luminex xTAG RVP FAST v2 test for the detection of respiratory viral infections were 0.99 (0.98-0.99) and 0.88 (0.87-0.90), respectively. Additionally, the negative and positive likelihood ratios were 0.14 (0.11-0.19) and 87.42 (61.88-123.50), respectively. Moreover, the diagnostic odds ratio and area under the curve of summary receiver operating characteristic were 714.80 and 0.9886, respectively.

CONCLUSION

The Luminex xTAG RVP FAST v2 test could be a reliable and rapid diagnostic method for multiple respiratory viral infections.

Micro and Nanoscale Technologies for Diagnosis of Viral Infections

Viral infection is one of the leading causes of mortality worldwide. The growth of globalization significantly increases the risk of virus spreading, making it a global threat to future public health. In particular, the ongoing coronavirus disease 2019 (COVID-19) pandemic outbreak emphasizes the importance of devices and methods for rapid, sensitive, and cost-effective diagnosis of viral infections in the early stages by which their quick and global spread can be controlled. Micro and nanoscale technologies have attracted tremendous attention in recent years for a variety of medical and biological applications, especially in developing diagnostic platforms for rapid and accurate detection of viral diseases. This review addresses advances of microneedles, microchip-based integrated platforms, and nano- and microparticles for sampling, sample processing, enrichment, amplification, and detection of viral particles and antigens related to the diagnosis of viral diseases. Additionally, methods for the fabrication of microchip-based devices and commercially used devices are described. Finally, challenges and prospects on the development of micro and nanotechnologies for the early diagnosis of viral diseases are highlighted.

Assay System for Simultaneous Detection of SARS-CoV-2 and Other Respiratory Viruses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggers disease with nonspecific symptoms that overlap those of infections caused by other seasonal respiratory viruses (RVs), such as the influenza virus (Flu) or respiratory syncytial virus (RSV). A molecular assay for accurate and rapid detection of RV and SARS-CoV-2 is crucial to manage these infections. Here, we compared the analytical performance and clinical reliability of Allplex™ SARS-CoV-2/FluA/FluB/RSV (SC2FabR; Seegene Inc., Seoul, South Korea) kit with those of four commercially available RV detection kits. Upon testing five target viral strains (SARS-CoV-2, FluA, FluB, RSV A, and RSV B), the analytical performance of SC2FabR was similar to that of the other kits, with no significant difference (p ≥ 0.78) in z-scores. The efficiency of SC2FabR (E-value, 81-104%) enabled reliable SARS-CoV-2 and seasonal RV detection in 888 nasopharyngeal swab specimens processed using a fully automated nucleic acid extraction platform. Bland-Altman analyses revealed an agreement value of 95.4% (SD ± 1.96) for the kits, indicating statistically similar results for all five. In conclusion, SC2FabR is a rapid and accurate diagnostic tool for both SARS-CoV-2 and seasonal RV detection, allowing for high-throughput RV analysis with efficiency comparable to that of commercially available kits. This can be used to help manage respiratory infections in patients during and after the coronavirus disease 2019 pandemic.

Rapid Molecular Tests for Detecting Respiratory Pathogens Reduced the Use of Antibiotics in Children

Multiplex polymerase chain reaction (mPCR) is increasingly being used to diagnose infections caused by respiratory pathogens in pediatric inpatient facilities. mPCR assays detect a broader array of viruses, with higher specificity and sensitivity and faster turnaround than previous assays. We adapted the FilmArray Respiratory Panel (FA-RP) for diagnosing respiratory infections. FA-RP is an in vitro mPCR assay that simultaneously and rapidly (in about 1 h) detects 20 pathogens directly from respiratory specimens. Here, we studied the clinical efficacy of FA-RP in children who underwent testing for respiratory pathogens at Yeungnam University Hospital from November 2015 to August 2018. From November 2015 to June 2016, routine mPCR testing was performed on nasopharyngeal swabs using the routine mPCR kit. From November 2016 to July 2018, mPCR testing was performed using FA-RP. A total of 321 tests by routine mPCR and 594 tests by FA-RP were included. The positive detection rates for routine mPCR and FA-RP were 71.3% and 83.3%, respectively. FA-RP reduced the lead time, waiting time, turnaround time, intravenous (IV) antibiotic use, and length of hospital stay for pediatric patients. The decreased use of antibiotics is expected to reduce antibiotic resistance in children.

Nucleic acid amplification tests on respiratory samples for the diagnosis of coronavirus infections: a systematic review and meta-analysis

BACKGROUND

Management and control of coronavirus disease 2019 (COVID-19) relies on reliable diagnostic testing.

OBJECTIVES

To evaluate the diagnostic test accuracy (DTA) of nucleic acid amplification tests (NAATs) for the diagnosis of coronavirus infections.

DATA SOURCES

PubMed, Web of Science, the Cochrane Library, Embase, Open Grey and conference proceeding until May 2019. PubMed and medRxiv were updated for COVID-19 on 31st August 2020.

STUDY ELIGIBILITY

Studies were eligible if they reported on agreement rates between different NAATs using clinical samples.

PARTICIPANTS

Symptomatic patients with suspected upper or lower respiratory tract coronavirus infection.

METHODS

The new NAAT was defined as the index test and the existing NAAT as reference standard. Data were extracted independently in duplicate. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Confidence regions (CRs) surrounding summary sensitivity/specificity pooled by bivariate meta-analysis are reported. Heterogeneity was assessed using meta-regression.

RESULTS

Fifty-one studies were included, 22 of which included 10 181 persons before COVID-19 and 29 including 8742 persons diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The overall summary sensitivity was 89.1% (95%CR 84.0-92.7%) and specificity 98.9% (95%CR 98.0-99.4%). Nearly all the studies evaluated different PCRs as both index and reference standards. Real-time RT PCR assays resulted in significantly higher sensitivity than other tests. Reference standards at high risk of bias possibly exaggerated specificity. The pooled sensitivity and specificity of studies evaluating SARS-COV-2 were 90.4% (95%CR 83.7-94.5%) and 98.1% (95%CR 95.9-99.2), respectively. SARS-COV-2 studies using samples from the lower respiratory tract, real-time RT-PCR, and tests targeting the N or S gene or more than one gene showed higher sensitivity, and assays based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP), especially when targeting only the RNA-dependent RNA polymerase (RdRp) gene, showed significantly lower sensitivity compared to other studies.

CONCLUSIONS

Pooling all studies to date shows that on average 10% of patients with coronavirus infections might be missed with PCR tests. Variables affecting sensitivity and specificity can be used for test selection and development.

Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections

Respiratory viral infections are associated with a wide range of acute syndromes and infectious disease processes in children and adults worldwide. Many viruses are implicated in these infections, and these viruses are spread largely via respiratory means between humans but also occasionally from animals to humans. This article is an American Society for Microbiology (ASM)-sponsored Practical Guidance for Clinical Microbiology (PGCM) document identifying best practices for diagnosis and characterization of viruses that cause acute respiratory infections and replaces the most recent prior version of the ASM-sponsored Cumitech 21 document, Laboratory Diagnosis of Viral Respiratory Disease, published in 1986. The scope of the original document was quite broad, with an emphasis on clinical diagnosis of a wide variety of infectious agents and laboratory focus on antigen detection and viral culture. The new PGCM document is designed to be used by laboratorians in a wide variety of diagnostic and public health microbiology/virology laboratory settings worldwide. The article provides guidance to a rapidly changing field of diagnostics and outlines the epidemiology and clinical impact of acute respiratory viral infections, including preferred methods of specimen collection and current methods for diagnosis and characterization of viral pathogens causing acute respiratory tract infections. Compared to the case in 1986, molecular techniques are now the preferred diagnostic approaches for the detection of acute respiratory viruses, and they allow for automation, high-throughput workflows, and near-patient testing. These changes require quality assurance programs to prevent laboratory contamination as well as strong preanalytical screening approaches to utilize laboratory resources appropriately. Appropriate guidance from laboratorians to stakeholders will allow for appropriate specimen collection, as well as correct test ordering that will quickly identify highly transmissible emerging pathogens.

Rapid Detection of Respiratory Pathogens for Community-Acquired Pneumonia by Capillary Electrophoresis-Based Multiplex PCR

Community-acquired pneumonia (CAP) is a common infectious disease linked to high rates of morbidity and mortality. Fast and accurate identification of the pathogens responsible for CAP will aid in diagnosis. We established a capillary electrophoresis-based multiplex PCR (CEMP) panel to enable the detection of viral and bacterial pathogens associated with CAP. The assay simultaneously detects and identifies the 13 common unculturable CAP viral and bacterial pathogens within 4 h. We evaluated the performance of a commercially available panel with 314 samples collected from CAP patients. We compared the results to those obtained with the liquid chip-based Luminex xTAG Respiratory Viral Panel (RVP) Fast Kit (for viruses) and the agarose gel-based Seegene PneumoBacter ACE Detection Kit (for atypical bacteria). All positive samples were further verified by the Sanger sequencing method. The sensitivity, specificity, positive predictive value, and negative predictive value of CEMP were 97.31%, 100%, 100%, and 99.85%, respectively. CEMP provides a rapid and accurate method for the high-throughput detection of pathogens in patients with CAP.

Evaluation of Seegene Allplex Respiratory Panel 1 kit for the detection of influenza virus and human respiratory syncytial virus

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Allplex RP1 assay is a highly sensitive, specific, and suitable for detection of FLUV and HRSV, including FLUAV subtyping.

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Allplex RP1 is a hands-on-time saving assay due to the automated nucleic acid extraction and PCR setup on the NIMBUS platform suitable for the hospital routine diagnostic.

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Beyond the respiratory virus detection, Allplex RP1 assay provides a valuable data for epidemiological purposes.

Background

Influenza (FLUV) and human respiratory syncytial (HRSV) viruses are etiological agents of respiratory infections that cause a significant morbidity and mortality worldwide. A rapid and accurate diagnosis of these respiratory viruses is essential for an appropriate patient management. Molecular tests are the best detection option due to their high sensitivity and specificity. Seegene’s Allplex™ Respiratory Panel 1 (Allplex RP1) is a real-time one-step RT-PCR assay for the simultaneous detection of FLUAV, FLUBV, HRSV-A and HRSV-B. In addition, it allows the determination of FLUAV subtype (H1, H3 and H1pdm09).

Objectives

This study aims to evaluate Allplex RP1 as a rapid molecular test for the detection of FLUAV, FLUBV, HRSV-A and HRSV-B viruses.

Study design

The Allplex RP1 assay will be compared with other two commercial molecular assays, Prodesse ProFlu+ and ProFAST+ (Hologic, Madison, WI, USA), and GeneXpert Flu/RSV XC (Cepheid, USA).

Results

Allplex RP1, ProFlu+ and GeneXpert tests showed 95%, 91% and 96% of accuracy; and 94%, 88% and 95% of sensitivity, respectively. Moreover, Allplex RP1 showed a FLUAV subtype sensitivity of 91% and 88% for FLUAV-H1pdm09 and FLUAV-H3 respectively, and ProFAST+ assay showed sensitivities of 100% for both targets. The three assays showed a 100% of specificity and PPV, while the NPV were 84%, 73% and 86% for Allplex RP1, Prodesse and GeneXpert, respectively.

Conclusions

In this study, Seegene’s Allplex RP1 assay showed to be highly sensitive, specific, and suitable for detection of FLUV and HRSV, including FLUAV subtyping. In addition, it is also a hands-on-time saving assay due to the automated nucleic acid extraction and PCR setup.