Owing to advancements in molecular diagnostics, recent years have seen an increasing number of laboratories adopting respiratory viral panels to detect respiratory pathogens. In December 2015, the NxTAG respiratory pathogen panel (NxTAG RPP) was approved by the United States Food and Drug Administration. We compared the clinical performance of this new assay with that of the xTAG respiratory viral panel (xTAG RVP) FAST v2 using 142 clinical samples and 12 external quality assessment samples. Discordant results were resolved by using a laboratory-developed respiratory viral panel. The NxTAG RPP achieved 100% concordant negative results and 86.6% concordant positive results. It detected one coronavirus 229E and eight influenza A/H3N2 viruses that were missed by the xTAG RVP FAST v2. On the other hand, the NxTAG RPP missed one enterovirus/rhinovirus and one metapneumovirus that were detected by FAST v2. Both panels correctly identified all the pathogens in the 12 external quality assessment samples. Overall, the NxTAG RPP demonstrated good diagnostic performance. Of note, it was better able to subtype the influenza A/H3N2 viruses compared with the xTAG RVP FAST v2.
Coronavirus ; Hand ; Influenza, Human ; Metapneumovirus ; Pathology, Molecular ; Respiratory Tract Infections ; United States Food and Drug Administration

PURPOSE: This study aimed to investigate the association between respiratory virus infection and pneumococcal colonization in children. METHODS: From May 2009 to June 2010, nasopharyngeal (NP) aspirates were obtained from patients under 18 years old who visited Seoul National University Children's Hospital for respiratory symptoms. NP samples were used to detect respiratory viruses (influenza virus A and B, parainfluenza virus 1, 2 and 3, respiratory syncytial virus A and B, adenovirus, rhinovirus A/B, human metapneumovirus, human coronavirus 229E/NL63 and OC43/HKU1) by RT-PCR and pneumococcus by culture. RESULTS: Median age of the patients was 27 months old. A total of 1,367 NP aspirates were tested for respiratory viruses and pneumococcus. Pneumococcus was isolated from 228 (16.7%) of samples and respiratory viruses were detected from 731 (53.5%). Common viruses were rhinovirus (18.4%), respiratory syncytial virus (RSV) A (10.6%), adenovirus (6.9%), influenza virus A (6.8%). Pneumococcal isolation rate was significantly higher in the cases of positive virus detection than negative detection [21.3% (156/731) vs. 11.3% (72/636), P<0.001]. For individual viruses, pneumococcal isolation rate was positively associated with detection of influenza virus A [24.7% (23/93) vs 16.1% (205/1274), P=0.001], RSV A [28.3% (41/145) vs 15.3% (187/1222), P=0.001], RSV B [31.3% (10/32) vs 16.3% (218/1335), P=0.042], rhinovirus A/B [22.6% (57/252) vs 15.3% (171/1115), P=0.010]. CONCLUSION: The study revealed that pneumococcal isolation from NP aspirates is related with respiratory virus detection. The result of this study could be used to investigate how respiratory viruses and pneumococcus cause clinical diseases.
Adenoviridae ; Child* ; Colon* ; Coronavirus ; Humans ; Metapneumovirus ; Orthomyxoviridae ; Paramyxoviridae Infections ; Respiratory Syncytial Viruses ; Rhinovirus ; Seoul ; Streptococcus pneumoniae

Adult ; Disease Outbreaks ; Humans ; Metapneumovirus ; Paramyxoviridae Infections ; epidemiology ; Respiratory Tract Infections ; epidemiology ; virology ; Students

BACKGROUND: The accurate and rapid identification of the causative viruses is important for the timely diagnosis and management of respiratory infections. Multiplex molecular diagnostic techniques have been widely adopted to detect respiratory viruses. We compared the results of a newly upgraded, multiplex, molecular bead-based respiratory viral panel (RVP) assay with the results of Anyplex II RV16 detection kit and AdvanSure RV real-time RT-PCR assay. METHODS: We tested 254 respiratory specimens and cultured viral strains using the Luminex xTAG RVP Fast v2 assay (Luminex Molecular Diagnostics, Canada) and Anyplex II RV16 detection kit and compared the results. Specimens showing discordant results between the two assays were tested with a AdvanSure RV real-time RT-PCR assay. RESULTS: Of the 254 respiratory specimens, there was total agreement in the results between the xTAG RVP Fast v2 assay and the other real-time PCR assay in 94.1–100% of the specimens. The agreement levels were relatively low (94.1–97.6%) for specimens of adenovirus, coronavirus NL63, and parainfluenza type 3. In comparison to the other assay, the xTAG RVP Fast v2 assay detected a higher number of parainfluenza type 3 (4 cases) and metapneumovirus (9 cases). CONCLUSIONS: The xTAG RVP Fast v2 assay showed comparable capabilities compared with the other assays; it will be useful for identifying respiratory viral infections in patients with respiratory symptoms. Clinicians should be aware of the characteristics of the assays they use, since different assays show different detectability for each virus.
Adenoviridae ; Coronavirus ; Diagnosis ; Humans ; Metapneumovirus ; Molecular Diagnostic Techniques ; Paramyxoviridae Infections ; Pathology, Molecular ; Real-Time Polymerase Chain Reaction ; Respiratory Tract Infections

PURPOSE: To identify the clinical and epidemiological characteristics of human metapneumovirus infections (hMPV) in children compared to respiratory syncytial virus A (RSV A) and B (RSV B). METHOD: A retrospective review of medical records was performed in 36 patients with hMPV infection, 106 with RSV A infection, and 51 with RSV B infection, from September 2007 to July 2012. RESULTS: The peak incidence of hMPV infection was observed in May, whereas for RSV infections in November and December. hMPV infection occurred in older patients compared to RSV A and B infection (29.9+/-32.5 months vs. 13.6+/-15.4 months, P<0.001; 29.9+/-32.5 months vs. 12.1+/-13.5 months, P<0.001, respectively). hMPV infection was more often associated with fever compared to RSV A (97.2% vs. 67.9%, P<0.001), while wheezing was less frequent compared to RSV A and B infection (16.7% vs. 47.2%, P=0.001; 16.7% vs. 37.3%, P=0.037, respectively). hMPV infection was more often diagnosed as pneumonia compared to RSV A infection (72.2% vs. 50.0%, P=0.047) while bronchiolitis was less frequent than in RSV A (5.6% vs. 34.9%, P=0.001) or RSV B infection (5.6% vs. 29.4%, P=0.006). In addition, intravenous antibiotic was more often prescribed for patients with hMPV infection than those with RSV A and B (69.4% vs. 39.6%, P=0.002; 69.4% vs. 43.1, P=0.015, respectively). CONCLUSION: This study identified characteristics of hMPV infection compared to RSV A and B infection. Seasonality in spring, higher age group, and higher proportion of pneumonia in hMPV infections may be a useful guide for management of respiratory viral infections in children.
Bronchiolitis ; Child ; Fever ; Humans* ; Incidence ; Medical Records ; Metapneumovirus* ; Pneumonia ; Respiratory Sounds ; Respiratory Syncytial Viruses* ; Retrospective Studies ; Seasons

Numerous studies have indicated that human metapneumovirus (hMPV) is an important viral pathogen in acute respiratory infections in children, presenting similar manifestations with respiratory syncytial virus (RSV). HMPV infection peaks in the winter-spring season and is more prevalent in younger ages, especially in children less than 1 year old. Host innate immune response has been implicated in recognition of pathogen-associated molecular patterns (PAMPs) of the virus. This recognition occurs through host pattern recognition receptors (PRRs). Toll like receptors (TLRs) are one of the largest class of PRRs which initiate and regulate adaptive immune responses. Some studies have indicated that TLR 3 and TLR 4 may play critical roles in hMPV infection. Construction of recombinant mutant viruses lacking one or two N-linked glycosylation sites in the F protein by using site-directed mutagenesis and reverse genetics may be helpful for developing attenuated live vaccines.
Humans ; Metapneumovirus ; immunology ; Paramyxoviridae Infections ; etiology ; prevention & control ; Vaccines, Attenuated ; immunology ; Vaccines, Synthetic ; immunology ; Viral Vaccines ; immunology

OBJECTIVETo study the epidemiology of human metapneumovirus (hMPV) infection in children and its relations with meteorological conditions in Suzhou.

METHODSamples obtained from 6655 children hospitalized with acute respiratory tract infections (ARIs) during the period from 2006 to 2009, were tested for virus pathogens. Nasopharyngeal aspirates were obtained from the children according to a standard protocol and were tested for respiratory syncytial virus (RSV), influenza viruses (IFV) A and B, parainfluenza virus (PIV) types 1, 2, and 3 and adenovirus (ADV) with direct immunofluorescence assay. Samples were tested for hMPV with reverse transcription polymerase chain reaction (RT-PCR). Meteorological conditions including mean temperature, relative humidity, rainfall amount, sum of sunshine and mean wind velocity were collected monthly. The relationship between activity of the virus and meteorological conditions was analyzed by linear regression and stepwise regression analysis.

RESULTViral pathogens were identified in 32.2% of 6655 specimens. The positive rate of hMPV was 8.9%, RSV was 15.7%, IFV, PIV and ADV detection rates were less than that of hMPV. The annual positive rate of hMPV from 2006 to 2009 was 8.2%, 8.1%, 12.7%, 7.4% respectively (χ(2) = 33.23, P < 0.05). The hMPV positive rate of the four seasons was 11.6%, 7.6%, 4.7% and 11.7%, respectively, detection rate in winter and spring was significantly higher than those in summer and autumn (χ(2) = 74.67, P < 0.001). The positive rate of hMPV and the monthly mean temperature was moderately correlated (r = -0.43), and the monthly average rainfall (r = -0.29), monthly mean relative humidity (r = -0.27), monthly average sunshine duration (r = -0.11), the monthly average wind speed (r = -0.13) had low correlations.

CONCLUSIONhMPV was the second most common viral pathogen of acute respiratory tract infection in children in Suzhou, which prevailed predominantly in the winter and spring. Climatic factors, especially temperature and rainfall may affect the prevalence of hMPV.

Child ; Child, Preschool ; China ; epidemiology ; Climate ; Female ; Humans ; Infant ; Male ; Metapneumovirus ; Respiratory Tract Infections ; epidemiology ; virology ; Seasons

OBJECTIVETo obtain isolated human metapneumovirus (HMPV) strains from clinical specimens collected from infants and children in Beijing and to promote the investigation on this important respiratory pathogen.

METHODClinical specimens including throat swabs from outpatients and nasopharyngeal aspirates from hospitalized children were collected from infants and children visited the affiliated children's hospital for acute respiratory infections during May 2008 to April 2009. HMPV positive specimens identified by RT-PCR and/or direct immunofluorescent assay with monoclonal antibody against HMPV were inoculated to LLC-MK(2) cells and incubated at 37°C and 33°C, respectively. The replication of the virus in the cells was detected by direct immunofluorescent assay followed by RT-PCR. The genotypes of the isolated virus strains were identified by RT-PCR.

RESULTOut of 1092 clinical specimens, 81 were HMPV positive by RT-PCR, the positive rate was 7.4% (81/1092). Among these positive specimens, 33 were inoculated to LLC-MK(2) cells and the replication of HMPV was revealed by antigen detection and RT-PCR from 5 out of these 33 inoculates. These isolated viruses could be passed in LLC-MK(2) cells and were not cross-reacted with other common respiratory viruses, such as ADV, RSV and Parainfluenza viruses 1/2/3 by monoclonal antibodies against these viruses in direct immunofluorescent assay. The HMPV was more likely to be isolated from fresh specimens within 24 hours after the collection of specimens which were not frozen. Four of the 5 isolated strains were identified as genotype A and 1 as genotype B. Unlike other respiratory viruses, these isolated HMPV did not show specific CPE in cell culture and the replication of the virus was identified by antigen detection and RT-PCR.

CONCLUSIONHMPV of both genotypes were isolated from infants and children with acute respiratory infections in Beijing which will accelerate the investigation of this important virus.

Acute Disease ; Child ; China ; Genes, Viral ; genetics ; Genotype ; Humans ; Infant ; Metapneumovirus ; isolation & purification ; Respiratory Tract Infections ; virology

OBJECTIVETo determine whether human metapneumovirus (hMPV) was circulating in Suzhou area and the epidemiology and clinical features associated with hMPV infection.

METHODSamples were collected from January 2006 to December 2007; respiratory specimens were tested for the presence of hMPV by reverse-transcription polymerase Chain reaction (RT-PCR). PCR products of hMPV N gene from some patients were randomly selected for sequencing analysis, and the sequences of the nucleotides and deduced amino acids were compared with those in the GenBank.

RESULTOf the 4702 patients screened, 8% had evidence of hMPV infection. The positive rate in 2006 and 2007 was 8.4% and 7.6%, respectively. The positive rates detected during January to March, November and December were higher. The median age of patients was 22. 56 months. The infected children were diagnosed as having upper respiratory tract infection (3.2%), laryngitis (2.1%), bronchiolitis (27.1%), pneumonia (55.9%), and asthma exacerbation (11.7%). Sequence analysis of these hMPV N genes showed 99%-100% homology with the registered sequence in GenBank.

CONCLUSION(1) hMPV accounted for a significant proportion of respiratory tract infection in infants and children. (2) hMPV prevailed predominantly in the winter and spring time. (3) Clinically, hMPV infection can not be discriminated from the infection with other respiratory tract viruses.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Male ; Metapneumovirus ; Prevalence ; Respiratory Tract Infections ; epidemiology ; virology

BACKGROUNDHuman metapneumovirus (hMPV) has recently been recognized as a notable respiratory pathogen in children. However, no isolation processes and only a limited understanding of hMPV epidemiology present in Chinese children are documented by far.

METHODSNasopharyngeal aspirates from 86 hospitalized children with acute respiratory tract infections from December 2004 to July 2005 were inoculated onto Vero-E6 cells for hMPV isolation. Total RNA was extracted from infected cells with a cytopathic effect and then subjected to a RT-PCR amplification of the N and F genes of the hMPV. Nucleotide sequences of amplified F gene products were examined using a variation analysis with the MegAlign program and the phylogenetic tree construction using the neighbor-joining algorithm with a Phylip package.

RESULTSSix strains of hMPV were isolated from the samples during winter, spring and summer. The most common symptoms were coughing and cyanosis, and the diagnoses were bronchiolitis, bronchopneumonia, infantile asthma, or upper respiratory tract infection. All isolates were in the A2 genetic sublineage and shared a high percentage of homology with the F gene in the nucleotide (99.8%-100%) and amino acid (99.3%-100%) sequences.

CONCLUSIONSThis report indicates that hMPV is an important viral agent for acute respiratory tract infections present in Chongqing, China. Knowledge of phylogeny and genes will benefit the studies on the treatment and prophylaxis of hMPV infection.

China ; Humans ; Infant ; Infant, Newborn ; Metapneumovirus ; classification ; genetics ; isolation & purification ; Paramyxoviridae Infections ; virology ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction