Respiratory Virus Panel Fast Assay Research Articles

A Single-Center Study of Viral Respiratory Tract Infections in Hospitalized Children From the Kurdistan Region of Iraq.

Viral respiratory infections are among the most common causes of disease in humans, particularly in young children, and remain a major public health problem worldwide. For many geographic regions, there is limited epidemiological information on the main causative agents of these diseases. In this article, we investigated, in a prospective study, the viral agents leading to acute respiratory disease in children younger than 15 years of age who were admitted to the pediatric emergency unit of a major teaching hospital in Erbil City, capital of the Kurdistan region, Iraq. Nasopharyngeal samples obtained from 269 hospitalized children were analyzed for viral respiratory pathogens using the xTAG Respiratory Virus Panel Fast assay, and the data were correlated with the clinical and demographic information available for these patients. One or more respiratory virus(es) were detected in 203 out of 269 (75.5%) samples. The most frequent viruses were enterovirus/rhinovirus (n = 88; 32.7%), respiratory syncytial virus (n = 55; 20.4%), and human metapneumovirus (n = 36; 13.4%). In 42 samples (15.6%), coinfections with 2 or more respiratory viruses were detected, with enterovirus/rhinovirus, respiratory syncytial virus, human metapneumovirus, and adenovirus being identified as the most common agents in viral coinfections in these patients.

Partial comparison of the NxTAG Respiratory Pathogen Panel Assay with the Luminex xTAG Respiratory Panel Fast Assay V2 and singleplex real-time polymerase chain reaction for detection of respiratory pathogens

In this study, 185 nasopharyngeal swabs were tested to compare the sensitivity and specificity of the Luminex NxTAG (NxTAG) Respiratory Pathogen Panel (RPP) Assay with those of the Luminex Respiratory Virus Panel (RVP) Fast Assay v2 and singleplex real-time polymerase chain reaction (PCR). The NxTAG Assay identified at least one infectious agent in 164 (88.7%) of the swabs. In 91 (6.2%) tests with negative results with the RVP Fast Assay v2, a virus was identified by the NxTAG (P < 0.001). With the NxTAG Assay, the detection rates were significantly higher for respiratory syncytial virus (P = 0.003), human metapneumovirus (P < 0.001), human rhinovirus/human enterovirus (P = 0.009) and human adenovirus (P < 0.001). Finally, the NxTAG Assay identified M. pneumoniae in 32 of 44 (72.7%) PCR-positive samples. However, the concordance with real-time PCR results was low for both assays. In conclusion, the results indicate that the NxTAG Assay overcomes some of the limitations of previous Luminex assays, although further studies are needed for a more complete evaluation of the new assay.

Identification of Human Adenovirus in Respiratory Samples with Luminex Respiratory Virus Panel Fast V2 Assay and Real-Time Polymerase Chain Reaction.

In order to compare the last version of the Respiratory Virus Panel (RVP) Fast assay for human Adenovirus (hAdv) detection with a specific real-time polymerase chain reaction (qPCR), which is considered the gold standard for hAdv detection, nasopharyngeal samples collected from 309 children (age range, four months to eight years) with respiratory tract infection were tested using the RVP Fast v2 assay (Luminex Molecular Diagnostics, Inc., Toronto, ON, Canada) and a specific TaqMan qPCR to identify hAdv DNA. The RVP Fast v2 assay detected 30/61 (49.2%) hAdv infections that had been identified by real-time qPCR, demonstrating a significantly lower detection rate (p < 0.001). The sensitivity of the RVP Fast v2 assay in comparison to qPCR was lower in younger children (42.9% vs. 57.7%; Cohen’s kappa coefficient, 0.53); in samples with co-infections (40.0% vs. 56.7%; Cohen’s kappa coefficient, 0.52); and in samples with hAdv type C (45.9% vs. 57.1%; Cohen’s kappa coefficient, 0.60). Samples with lower viral loads were associated with a significantly lower sensitivity of the RVP Fast v2 assay (35.1% vs. 68.2%, p = 0.01; Cohen’s kappa coefficients, 0.49). The RVP Fast v2 assay has important limitations for the detection of hAdv and cannot be used to evaluate whether hAdvs are the main etiologic agent responsible for an outbreak or when epidemiological studies are performed.

Molecular viral epidemiology and clinical characterization of acute febrile respiratory infections in hospitalized children in Taiwan.

Acute respiratory infection (ARI) is a leading cause of morbidity and hospitalization in children. To profile the viruses causing ARI in children admitted to a community‐based hospital in central Taiwan, a cross‐sectional study was conducted on children under 14 years of age that were hospitalized with febrile ARI. Viral etiology was determined using conventional cell culture and a commercial respiratory virus panel fast assay (xTAG RVP), capable of detecting 19 different respiratory viruses and subtype targets. Demographic, clinical, and laboratory data were recorded and analyzed. The RVP fast assay identified at least one respiratory virus in 130 of the 216 specimens examined (60.2%) and rose to 137 (63.4%) by combining the results of cell culture and RVP fast assay. In order of frequency, the etiological agents identified were, rhinovirus/enterovirus (24.6%), respiratory syncytial virus (13.8%), adenovirus (11.5%), parainfluenza virus (9.2%), influenza B (8.4%), influenza A (5.4%), human metapneumovirus (4.6%), human coronavirus (2%), and human bocavirus (2%). Co‐infection did not result in an increase in clinical severity. The RVP assay detected more positive specimens, but failed to detect 6 viruses identified by culture. The viral detection rate for the RVP assay was affected by how many days after admission the samples were taken (P = 0.03). In conclusion, Rhinovirus/enterovirus, respiratory syncytial virus, and adenovirus were prevalent in this study by adopting RVP assay. The viral detection rate is influenced by sampling time, especially if the tests are performed during the first three days of hospitalization. J. Med. Virol. 87:1860–1866, 2015. © 2015 Wiley Periodicals, Inc.

Bocavirus Infection in Otherwise Healthy Children with Respiratory Disease.

To evaluate the role of human bocavirus (hBoV) as a causative agent of respiratory disease, the importance of the viral load in respiratory disease type and severity and the pathogenicity of the different hBoV species, we studied all hBoV-positive nasopharyngeal samples collected from children who attended an emergency room for a respiratory tract infection during three winters (2009–2010, 2011–2012, and 2013–2014). Human bocavirus was detected using the respiratory virus panel fast assay and real-time PCR. Of the 1,823 nasopharyngeal samples, 104 (5.7%) were positive for hBoV; a similar prevalence was observed in all three periods studied. Among hBoV-infected children, 53.8% were between 1–2 years old, and hBoV was detected alone in 57/104 (54.8%) cases. All of the detected hBoV strains belonged to genotype 1. The median hBoV load was significantly higher in samples containing strains with both the N546H and T590S mutations compared to other samples (p<0.05). Children with a single hBoV-1 infection more frequently had upper respiratory tract infections (URTIs) than those who were co-infected (37.0% vs 17.8%, respectively, p = 0.04). The duration of hospitalization was longer among children with high viral loads than that observed among children with low viral loads (8.0 ±2.2 days vs 5.0 ±1.5 days, respectively, p = 0.03), and the use of aerosol therapy was more frequent among children with high viral loads than among those with low viral loads (77.1% vs 55.7%, respectively, p = 0.04). This study shows that hBoV is a relatively uncommon but stable infectious agent in children and that hBoV1 seems to be the only strain detected in Italy in respiratory samples. From a clinical point of view, hBoV1 seems to have in the majority of healthy children relatively low clinical relevance. Moreover, the viral load influences only the duration of hospitalization and the use of aerosol therapy without any association with the site of the respiratory disease.

Characteristics and Their Clinical Relevance of Respiratory Syncytial Virus Types and Genotypes Circulating in Northern Italy in Five Consecutive Winter Seasons.

In order to investigate the genetic diversity and patterns of the co-circulating genotypes of respiratory syncytial virus (RSV) and their possible relationships with the severity of RSV infection, we studied all of the RSV-positive nasopharyngeal samples collected from children during five consecutive winters (2009–2010, 2010–2011, 2011–2012, 2012–2013 and 2013–2014). The RSVs were detected using the respiratory virus panel fast assay and single-tube RT-PCR, their nucleotides were sequenced, and they were tested for positive selection. Of the 165 positive samples, 131 (79.4%) carried RSV-A and 34 (20.6%) RSV-B; both groups co-circulated in all of the study periods, with RSV-A predominating in all the seasons except for winter 2010–2011, which had a predominance of RSV-B. Phylogenetic analysis of the RSV-A sequences identified genotypes NA1 and ON1, the second replacing the first during the last two years of the study period. The RSV-B belonged to genotypes BA9 and BA10. BA9 was detected in all the years of the study whereas BA only desultorily. Comparison of the subjects infected by RSV-A and RSV-B types did not reveal any significant differences, but the children infected by genotype A/NA1 more frequently had lower respiratory tract infections (p<0.0001) and required hospitalisation (p = 0.007) more often than those infected by genotype A/ON1. These findings show that RSV has complex patterns of circulation characterised by the periodical replacement of the predominant genotypes, and indicate that the circulation and pathogenic role of the different RSV strains should be investigated as each may have a different impact on the host. A knowledge of the correlations between types, genotypes and disease severity may also be important in order to be able to include the more virulent strains in future vaccines.

Pneumococcal Bacterial Load Colonization as a Marker of Mixed Infection in Children With Alveolar Community-acquired Pneumonia and Respiratory Syncytial Virus or Rhinovirus Infection

The main aim of this study was to evaluate whether nasopharyngeal Streptococcus pneumoniae colonization in children with alveolar community-acquired pneumonia (CAP) and respiratory syncytial virus (RSV) or rhinovirus (RV) infection indicates a mixed lung infection. The nasopharyngeal secretions of 530 children with radiographically confirmed CAP were tested using the Luminex x TAG respiratory virus panel fast assay. Real-time polymerase chain reaction for the autolysin-A (LytA) and wzg (cpsA) genes of S. pneumoniae was performed on the RSV- and RV-positive samples. Sixty-five of the 126 RSV-positive children (51.6%) were colonized with S. pneumoniae. Mean bacterial load was significantly higher in the patients with alveolar involvement (4.54±1.47 log10 DNA copies/mL vs. 3.75±1.62 log10 DNA copies/mL; P=0.04). Serotypes 5 and 19A were almost exclusively identified in the children with RSV and alveolar CAP, although the difference was statistically significant only for serotype 19A (P=0.03). Eighty-three of the 134 RV-positive children (61.9%) were colonized with S. pneumoniae and again mean bacterial load was significantly higher in the patients with alveolar involvement (4.21±1.37 log10 DNA copies/mL vs. 3.41±1.47 log10 DNA copies/mL; P=0.03). Serotypes 1, 5 and 19A were more frequently identified in the children with RV and alveolar CAP, although the difference was statistically significant only for serotype 5 (P=0.04). In children with alveolar CAP and RSV or RV infection, the determination of nasopharyngeal pneumococcal bacterial load and identification of the serotypes can contribute to the diagnosis of mixed lung infection.

Performance of a rapid molecular multiplex assay for the detection of influenza and picornaviruses

Multiplex assays are a new strategy for diagnosing respiratory infections. These assays are better than those based on cultures or antigen detection, but few data are available for comparing them to monoplex polymerase chain reactions (PCRs). This study evaluated the performance of the Luminex xTAG Respiratory Viral Panel (RVP) Fast assay with reference to 2 real-time PCR assays for detecting type A influenza H1 viruses and human enteroviruses and rhinoviruses. This was an analysis of nasal swab specimens obtained from 590 outpatients suffering from acute respiratory tract disease between September 2009 and February 2010. The RVP Fast assay performed well in less than 4 h for detecting type A influenza H1 viruses, particularly (H1N1)pdm09, and human entero/rhinoviruses, with 95.2% and 90.05% agreement, respectively, when compared to monoplex real-time PCR assays. This multiplex assay also detected at least 1 virus in 69.3% of the specimens and detected multiple infections in 40 samples. The multiplex assay detected clinically important viruses in a single genomic test. It will thus be useful for detecting several viruses causing respiratory tract disorders.

Comparison of three multiplex PCR assays for the detection of respiratory viral infections: evaluation of xTAG respiratory virus panel fast assay, RespiFinder 19 assay and RespiFinder SMART 22 assay

BackgroundA broad spectrum of pathogens is causative for respiratory tract infections, but symptoms are mostly similar. Therefore, the identification of the causative viruses and bacteria is only feasible using multiplex PCR or several monoplex PCR tests in parallel.MethodsThe analytical sensitivity of three multiplex PCR assays, RespiFinder-19, RespiFinder-SMART-22 and xTAG-Respiratory-Virus-Panel-Fast-Assay (RVP), were compared to monoplex real-time PCR with quantified standardized control material. All assays include the most common respiratory pathogens.ResultsTo compare the analytical sensitivity of the multiplex assays, samples were inoculated with 13 different quantified viruses in the range of 101 to 105 copies/ml. Concordant results were received for rhinovirus, whereas the RVP detected influenzavirus, RSV and hMPV more frequently in low concentrations. The RespiFinder-19 and the RespiFinder-SMART-22 showed a higher analytical sensitivity for adenoviruses and coronaviruses, whereas the RVP was incapable to detect adenovirus and coronavirus in concentrations of 104 copies/ml. The RespiFinder-19 and RespiFinder-SMART-22A did not detect influenzaviruses (104 copies/ml) and RSV (103 copies/ml). The detection of all 13 viruses in one sample was only achieved using monoplex PCR. To analyze possible competitive amplification reactions between the different viruses, samples were further inoculated with only 4 different viruses in one sample. Compared to the detection of 13 viruses in parallel, only a few differences were found.The incidence of respiratory viruses was compared in tracheal secretion (TS) samples (n = 100) of mechanically ventilated patients in winter (n = 50) and summer (n = 50). In winter, respiratory viruses were detected in 32 TS samples (64%) by RespiFinder-19, whereas the detection rate with RVP was only 22%. The most frequent viruses were adenovirus (32%) and PIV-2 (20%). Multiple infections were detected in 16 TS samples (32%) by RespiFinder-19. Fewer infections were found in summer (RespiFinder-19: 20%; RVP: 6%). All positive results were verified using monoplex PCR.ConclusionsMultiplex PCR tests have a broad spectrum of pathogens to test at a time. Analysis of multiple inoculated samples revealed a different focus of the detected virus types by the three assays. Analysis of clinical samples showed a high concordance of detected viruses by the RespiFinder-19 compared to monoplex tests.

Impact of viral infections in children with community‐acquired pneumonia: results of a study of 17 respiratory viruses

Please cite this paper as: Esposito et al. (2012) Impact of viral infections in children with community‐acquired pneumonia: results of a study of 17 respiratory viruses. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00340.x. Background Little is known about the prevalence of viral infections in children with community‐acquired pneumonia (CAP). Objectives To describe the clinical and virological data collected from children with radiographically confirmed CAP in whom 17 respiratory viruses were sought in respiratory secretion samples during the acute phase of the disease. Patients and methods The study involved 592 children with radiographically confirmed CAP whose respiratory secretion samples were tested using the Luminex xTAG Respiratory Virus Panel Fast assay, which simultaneously detects influenza A virus, influenza B virus, respiratory syncytial virus (RSV)‐A and ‐B, parainfluenzavirus‐1, ‐2, ‐3, and ‐4, adenovirus, human metapneumovirus, coronaviruses 229E, NL63, OC43, and HKU1, enterovirus/rhinovirus, and bocavirus. A real‐time PCR assay was used to identify the rhinovirus in the enterovirus/rhinovirus‐positive samples. Results A total of 435 children (73·5%) were positive for at least one virus: the most frequently detected was RSV, which was found in 188 (31·7%), followed by rhinovirus (n = 144, 24·3%), bocavirus (n = 60, 10·1%), influenza viruses (n = 57, 9·6), and hMPV (n = 49, 8·2%). Viral co‐infections were found in 117 children (19·7% of the enrolled children; 26·9% of those with viral infections). Marginal differences were found between the infections owing to a single virus. Co‐infections showed radiographic evidence of alveolar pneumonia significantly more frequently than single infections (OR 1·72, 95% CI 1·05–2·81). Conclusions The findings of this study highlight the importance of respiratory viruses (mainly RSV and rhinovirus) in children with CAP and show the characteristics of both the single infections and co‐infections associated with the disease.

Detection of Respiratory Viruses Among Pilgrims in Saudi Arabia During the Time of a Declared Influenza A(H1N1) Pandemic

BackgroundThe objectives of this study were to determine whether pilgrim attendance at the Hajj was associated with an increased risk of acquiring influenza, and other respiratory viruses, and to evaluate the compliance of pilgrims with influenza vaccination and other recommended preventive measures.MethodsA cross‐sectional survey was conducted among pilgrims as they arrived at the King Abdulaziz International Airport in Jeddah for the 2009 Hajj and as they departed from the same airport during the week after the Hajj. Nasopharyngeal and throat swabs were tested for 18 respiratory virus types and subtypes using the xTAG Respiratory Viral Panel FAST assay.ResultsA total of 519 arriving pilgrims and 2,699 departing pilgrims were examined. Their mean age was 49 years and 58% were male. In all, 30% of pilgrims stated that they had received pandemic influenza A(H1N1) vaccine before leaving for the Hajj and 35% of arriving pilgrims reported wearing a face mask. Only 50% of arriving pilgrims were aware of preventive measures such as hand hygiene and wearing a mask. The prevalence of any respiratory‐virus infection was 14.5% (12.5% among arriving pilgrims and 14.8% among departing pilgrims). The main viruses detected (both groups combined) were rhinovirus‐enterovirus (N = 414, 12.9%), coronaviruses (N = 27, 0.8%), respiratory syncytial virus (N = 8, 0.2%), and influenza A virus (N = 8, 0.2%) including pandemic influenza A(H1N1) (N = 3, 0.1%). The prevalence of pandemic influenza A(H1N1) was 0.2% (N = 1) among arriving pilgrims and 0.1% (N = 2) among departing pilgrims. The prevalence of any respiratory virus infection was lower among those who said they received H1N1 vaccine compared to those who said they did not receive it (11.8% vs 15.6%, respectively, p = 0.009).ConclusionWe found very low pandemic influenza A(H1N1) prevalence among arriving pilgrims and no evidence that amplification of transmission had occurred among departing pilgrims.

Comparison of the Luminex xTAG Respiratory Viral Panel with xTAG Respiratory Viral Panel Fast for Diagnosis of Respiratory Virus Infections

Nucleic acid tests are sensitive and specific and provide a rapid diagnosis, making them invaluable for patient and outbreak management. Multiplex PCR assays have additional advantages in providing an economical and comprehensive panel for many common respiratory viruses. Previous reports have shown the utility of the xTAG respiratory viral panel (RVP) assay manufactured by Luminex Molecular Diagnostics for this purpose. A newer generation of this kit, released in Canada in early 2010, is designed to simplify the procedure and reduce the turnaround time by about 24 h. The assay methodology and targets included in this version of the kit are different; consequently, the objective of this study was to compare the detection of a panel of respiratory viral targets using the older Luminex xTAG RVP (RVP Classic) assay with that using the newer xTAG RVP Fast assay. This study included 334 respiratory specimens that had been characterized for a variety of respiratory viral targets; all samples were tested by both versions of the RVP assay in parallel. Overall, the RVP Classic assay was more sensitive than the RVP Fast assay (88.6% and 77.5% sensitivities, respectively) for all the viral targets combined. Targets not detected by the RVP Fast assay included primarily influenza B virus, parainfluenza virus type 2, and human coronavirus 229E. A small number of samples positive for influenza A virus, respiratory syncytial virus B, human metapneumovirus, and parainfluenza virus type 1 were not detected by the RVP Classic assay and in general had low viral loads.

Comparison of the Luminex Respiratory Virus Panel Fast Assay with In-House Real-Time PCR for Respiratory Viral Infection Diagnosis

The Luminex xTAG Respiratory Virus Panel (RVP) assay has been shown to offer improved diagnostic sensitivity over traditional viral culture methods and to have a sensitivity comparable to those of individual real-time nucleic acid tests for respiratory viruses. The objective of this retrospective study was to test a new, streamlined version of this assay, the RVP Fast assay, which requires considerably less run time and operator involvement. The study compared the performance of the RVP Fast assay with those of viral culture, a direct fluorescent assay (DFA), and a panel of single and multiplex real-time PCRs in the testing of 286 respiratory specimens submitted to the Edinburgh Specialist Virology Centre for routine diagnosis of viral infection between December 2007 and February 2009. At least one respiratory viral infection was detected in 13.6% of specimens by culture and DFA combined, in 49.7% by real-time PCR, and in 46.2% by the RVP Fast assay. The sensitivity and specificity of the RVP Fast assay compared to the results of real-time PCR as the gold standard were 78.8% and 99.6%, respectively. Real-time PCR-positive specimens missed by the RVP Fast assay generally had low viral loads or were positive for adenovirus. Additionally, a small number of specimens were positive by the RVP Fast assay but were not detected by real-time PCR. For some viral targets, only a small number of positive results were found in our sample set using either method; therefore, the sensitivity of detection of the RVP Fast assay for individual targets could be investigated further with a greater number of virus-positive specimens.