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

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

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

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

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 features of human metapneumovirus (hMPV) and the respiratory syncytial virus (RSV) infection in children. METHODS:The participants of our study were 1,104 children who were admitted to Bungdang CHA hospital for lower respiratory infection from August 2006 through July 2007. Nasopharyngeal swabs were taken from the patients, and viruses were identified by RT-PCR. The clinical features of 51 patients with hMPV infection and 138 patients with RSV infection were compared by retrospective review of their medical records. RESULTS:The peak incidence of hMPV infection was noted in April, and that of RSV was noted in November. Both viruses had the highest incidence in patients age <1 year and hMPV infections occurred in 40% and 25% of patients age <6 months, respectively. In the hMPV group, 33.4% of the patients were age > or =2 years, while in the RSV group, 19% were age > or =2 years. In both groups, pneumonia was the most common clinical diagnosis, followed by acute bronchiolitis, acute bronchitis, and asthma. The white blood cell counts were higher in the RSV group, and fever was more frequent on admission in the hMPV group. CONCLUSION:hMPV was the fourth most common virus causing lower respiratory tract infections in children. The clinical features of hMPV infection were similar to those of RSV infection. This study may be helpful for the effective treatment of lower respiratory tract infection in children.
Asthma ; Bronchiolitis ; Bronchitis ; Child ; Fever ; Humans ; Incidence ; Leukocyte Count ; Metapneumovirus ; Pneumonia ; Respiratory Syncytial Viruses ; Respiratory Tract Infections ; Retrospective Studies ; Viruses

BACKGROUND: Multiplex PCR assay is a sensitive tool for the detection of various respiratory viruses. Seeplex RV12 ACE Detection (Seegene, Korea) assay is a multiplex RT-PCR assay for detection of 12 respiratory viruses. We had observed several cases with faint bands in the test. Those results were investigated in this study. METHODS: A total of 163 specimens were tested with Seeplex RV12 ACE Detection assay. The amplicons showing faint band in electrophoresis were reamplified and sequenced. RESULTS: A total of 99 viruses were detected in 80 specimens (49.1%). Twenty-four amplicons showed faint band in eletrophoresis. All of influenza virus A, parainfluenza viruses (PIV), coronavirus OC43, human metapneumovirus (HMPV) and adenovirus amplicons were reamplified, but 4 of 12 human rhinovirus amplicons were not reamplified. Sequences of reamplified PCR products showed homology of 95-99% to those of corresponding viruses in the National Center for Biotechnology Information database. CONCLUSIONS: Faint bands of influenza virus A, PIV-1, PIV-3, coronavirus OC43, HMPV and adenovirus in Seeplex RV12 ACE Detection assay are specific bands and seems to be weak positive results.
Adenoviridae ; Biotechnology ; Coronavirus ; Coronavirus OC43, Human ; Electrophoresis ; Humans ; Metapneumovirus ; Multiplex Polymerase Chain Reaction ; Orthomyxoviridae ; Paramyxoviridae Infections ; Polymerase Chain Reaction ; Rhinovirus

PURPOSE: This study was perfomed to analyze in detail the viral etiology of acute lower respiratory tract infections (ALRI) in Cheunan, Korea by multiplex RT-PCR, including human rhinovirus (hRV) and newly identified viruses such as human metapneumovirus (hMPV) and human coronavirus (HCoV-OC43, HCoV-229E/NL63). Method: Nasopharyngeal aspirates (NPA) were collected from 863 hospitalized children with ALRI on the first day of admission at Soonchunhyang University Cheonan Hospital and analyzed by multiplex RT-PCR from December 2005 to November 2006. RESULTS: Viral agents were detected from 474 subjects (54.9%). The identified viral pathogens were hRV 9.2%, hMPV 6.8%, HCoV-229E/NL63 1.4%, and HCoV-OC43 2.1%. Coinfections with > or =2 viruses were observed in 108 patients (22.8%). The major period of viral ALRI was the first year of life. Clinical diagnoses of viral ALRI were pneumonia (59.5%), bronchiolitis (24.7%), tracheobronchitis (11.4%), and croup (4%). The most common causes of bronchiolitis was respiratory syncytial virus B (RSV B), whereas hMPV, hRV, HCoV-229E/NL63, and HCoV-OC43 were commonly found in patients with pneumonia. The number of hMPV infections peaked between March and May 2006. HCoV-OC43 was prevalent from November to February 2006, whereas HCoV-229E and hRV were detected throughout the year. CONCLUSION: Although the study was confined to one year, hMPV was not detected during winter and peaked between March and April, which was not consistent with previous studies'. This present study indicates that HCoV is a less common respiratory pathogen in cases of ALRI in Korean children.
Bronchiolitis ; Child ; Child, Hospitalized ; Coinfection ; Coronavirus ; Croup ; Humans ; Korea ; Metapneumovirus ; Pneumonia ; Respiratory Syncytial Viruses ; Respiratory System ; Respiratory Tract Infections ; Rhinovirus

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