OBJECTIVETo investigate the infection status and epidemiological characteristics of influenza virus and respiratory syncytial virus (RSV) in influenza-like illness (ILI) of children ( ≤ 14 years) in Wuhan area from 2008 to 2012.

METHODSA total of 2854 cases of ILI patients ( ≤ 14 years) in a hospital of Wuhan were recruited in the study from July 2008 to June 2012. The sample of pharyngeal swab was collected from each patient, to extract the virus nucleic acids. Real-time fluorescent quantitation reverse transcription PCR (RT-PCR) method was applied to detect the subtypes of influenza virus and RSV, and then analyzed the time and age characteristics.

RESULTSOut of the 2854 cases, 758 (26.6%) were positive for influenza virus,including 547 (19.2%) influenza A virus positive samples and 211 (7.4%) influenza B virus positive samples. Usually, there were two peaks present in the annual curve of influenza virus, namely summer peak and winter/spring peak. The positive rate of influenza virus in 6-14 years old children (48.0%, 275/573) was significantly higher than that in 3-5 years old children (26.6%, 213/801) and that under 3 years old children (18.3%, 270/1480). The difference showed statistical significance (χ(2) = 187.432, P < 0.01). A total of 219 (7.7%) cases were positive for RSV,including 108 RSV-A positive samples and 112 RSV-B positive samples (1 co-infection). The epidemic of RSV showed an obvious seasonal pattern with peaks in autumn,winter and spring,which accounted for 96.8% (212/219) of all the cases; however, the annual incidence of RSV fluctuated greatly. The predominant subtype shifted every 2 years. RSV-B predominated during September 2008 and May 2009, December 2009 and March 2010, accounting for 76.6% (36/47) and 96.9% (62/64) respectively. RSV-A predominated during November 2010 and March 2011, September 2011 and April 2012, accounting for 92.5% (37/40) and 100.0% (48/48) respectively. With the increase of the age, the positive rate of RSV-A and RSV-B decreased gradually (RSV-A: χ(2) = 36.223, P < 0.01; RSV-B: χ(2) = 36.281, P < 0.01). The positive rates of RSV-A in children < 1,1,2,3,4,5-9 and 10-14 years old were 7.0% (26/373), 5.9% (39/662), 4.0% (18/445), 3.2% (13/406), 1.3% (3/236), 1.4% (7/517) and 0.9% (2/215) respectively; while, the positive rates of RSV-B in each age group were 6.4% (24/373), 6.0% (40/662), 4.5% (20/445), 4.4% (18/406), 1.3% (3/236), 1.0% (5/517) and 0.9% (2/215) respectively. The children aged 0-3 years old were more susceptible for RSV infection,accounting for 90.0% (197/219) of the total positive samples. During the outbreak of influenza A H1N1 in November 2009, the positive rate of RSW was 3.0% (3/100), lower than that in the same month of 2008, 2010 and 2011,which were separately 18.2% (6/33), 10.8% (10/93) and 10.0% (4/40). The difference showed statistical significance (χ(2) = 8.450, P < 0.05). During the outbreak of influenza A (H1N1) in January 2011,the positive rate of RSV was 5.7% (3/53), lower than those in the same month of 2009, 2010 and 2012, which was separately 21.7% (5/23), 28.6% (22/77) and 16.0% (8/50). The difference showed statistical significance (χ(2) = 11.233,P < 0.05). During the period of less influenza happened in September 2011, the RSV positive rate was 25.0% (10/40), higher than those in the same month of 2008, 2009 and 2010, which was separately 11.4% (4/35), 1.7% (2/118) and 0.0% (0/109). The difference showed statistical significance (χ(2) = 32.521, P < 0.01).

CONCLUSIONBoth influenza virus and RSV were important etiological agents of ILI of children in Wuhan. The characteristics of seasonal and age distributions of the two viruses were notably different; meanwhile, a certain inhibitional effect of influenza virus on RSV could be observed.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Influenza, Human ; epidemiology ; Male ; Orthomyxoviridae ; classification ; isolation & purification ; Respiratory Syncytial Virus Infections ; epidemiology ; Respiratory Syncytial Viruses ; classification ; isolation & purification

OBJECTIVETo investigate the distribution of respiratory viruses on throat swabs in hospitalized children with acute lower respiratory tract infection (ALRTI).

METHODSA total of 5,150 children with ALRTI who were admitted to Hebei Children's Hospital between March 2014 and February 2015 were enrolled to investigate the distribution of respiratory viruses in children with ALRTI. Direct immunofluorescence assay was performed for throat swabs from these children to detect influenza virus A (FA), influenza virus B (FB), adenovirus (ADV), respiratory syncytial virus (RSV), and parainfluenza virus types 1, 2, and 3 (PIV-1, PIV-2, and PIV-3).

RESULTSOf all the 5,150 throat swabs from hospitalized children, 2,155 (41.84%) had positive virus detection results. RSV had the highest detection rate (1,338 cases/25.98%), followed by PIV-3 (439 cases/8.52%) and FA (166 cases/3.22%), and 29 patients had mixed infection with 2 viruses. With the increasing age, the detection rates of viruses tended to decrease (χ2=279.623; P<0.01). The positive rate of RSV increased gradually from September, and reached the peak value (60.09%) in November; the lowest positive rate occurred in June (1.51%). The positive rate of PIV-3 was the highest in May (21.38%) and the lowest in November (1.77%).

CONCLUSIONSThe distribution of viruses in children with ALRTI varies with age and season, with RSV prevalence in autumn and winter and PIV-3 prevalence in spring and summer. RSV is the most common viral pathogen that causes ALRTI in hospitalized children.

Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Orthomyxoviridae ; isolation & purification ; Parainfluenza Virus 3, Human ; isolation & purification ; Respiratory Syncytial Viruses ; isolation & purification ; Respiratory Tract Infections ; virology ; Seasons

Child, Preschool ; Humans ; Infant ; Infant, Newborn ; Lung ; physiopathology ; virology ; Male ; Metapneumovirus ; isolation & purification ; Paramyxoviridae Infections ; diagnosis ; physiopathology ; Respiratory Function Tests ; Respiratory Syncytial Virus Infections ; diagnosis ; physiopathology ; Respiratory Syncytial Viruses ; isolation & purification

OBJECTIVETo investigate the distribution of pathogens of children with community acquired pneumonia (CAP) from the Chongqing area.

METHODSNasopharyngeal specimens and blood specimens of 1 613 children with CAP were collected between January 2014 and December 2014 for bacterial culture and detection of 7 respiratory viruses and antibodies against Mycoplasma pneumoniae (MP).

RESULTSThe overall positive rate of bacteria was 50.22% (810 cases). Hemophilus parainfluenzae (40.8%), Streptococcus pneumonia (29.7%) and Moraxelle catarrhalis (7.3%) were the predominant ones. Among the viruses, the top detected virus was respiratory syncytial virus (RSV, 58.3%), followed by parainfluenza virus type3 (17.4%) and adenovirus (14.3%). A total of 481 cases (29.82%) were MP-positive. The co-infection rate was 32.18% (519 cases), and the mixed infections of bacteria and viruses were common (47.4%).

CONCLUSIONSRSV and Hemophilus parainfluenzae are the major pathogens of CAP in children from the Chongqing area. MP is also an important pathogen. The co-infection of bacteria and viruses is prevalent.

Adolescent ; Child ; Child, Preschool ; Community-Acquired Infections ; etiology ; Female ; Haemophilus parainfluenzae ; isolation & purification ; Hospitalization ; Humans ; Infant ; Male ; Mycoplasma pneumoniae ; isolation & purification ; Pneumonia ; etiology ; Respiratory Syncytial Viruses ; isolation & purification

To understand the role of respiratory syncytial virus (RSV) in children with acute respiratory infections (ARI) in Tibet Autonomous Region and the contribution of two major groups of RSV, nasopharyngeal aspirates (NPA) were collected from hospitalized children with ARI in Department of Pediatrics, Tibet People's Hospital in Lasa, Tibet from April to July in 2011 and tested for seven common respiratory viruses and human metapneumovirus (hMPV) by direct immunofluorescence assay (DFA). Total RNAs were extracted from RSV positive samples by DFA and reverse transcripted to cDNA. Nested-PCR was employed to determine the genogroups of RSV, which were confirmed by real time-PCR and sequence analysis for G protein encoding gene. The Characteristics and variations of G genes from RSV in this project were identified by sequence comparison with those G genes in GenBank. Out of 167 samples, 65 were positive for respiratory viruses with a total positive rate of 38.9%, including 45 (69.2%, 45/65)positive samples for RSV. Among 42 samples that were positive for RSV and genotyped, 40 were identified as group A and 2 as group B. Sequence analysis of full-length G genes for 7 RSV of group A indicated that all of these belonged to subgroup GA2. The nucleotide identities between RSVs from Tibet and prototype A2 strain were 90.7%-91.8%, with 86.5%-87.2% identities of amino acid. The mutations of amino acids were mainly located in both ends of a highly conserved region in the ectodomain of the G proteins. The data indicated that RSV was the most important viral etiologic agent of ARI in spring of 2011 in Tibet and group A of RSV was predominant during the study period. High divergence existed in the ectodomain of G proteins of RSVs from Tibet.
Acute Disease ; Amino Acid Sequence ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Phylogeny ; Respiratory Syncytial Virus Infections ; virology ; Respiratory Syncytial Viruses ; chemistry ; classification ; genetics ; isolation & purification ; Respiratory Tract Infections ; virology ; Sequence Alignment ; Tibet ; Viral Proteins ; chemistry ; genetics

OBJECTIVETo study the virus spectrum of severe community-acquired pneumonia (CAP) and risk factors for the disease in children.

METHODSRespiratory secretion specimens were collected from 1096 children hospitalized with CAP from June 2007 to November 2008, including 100 cases of severe CAP. Respiratory viruses were detected by PCR, nest-PCR or RT-PCR. Clinical data on the children were analyzed by univariate and multivariate logistic regression analysis for examining risk factors for severe CAP.

RESULTSViral pathogens were isolated from 82 (82%) of the 100 cases with severe CAP. RSV was the most common (37%), followed by HBoV (25%) and HRV (18%). Mixed infection was noted in 32 cases (32%). The presence of underlying diseases (OR=6.623, P<0.01) and RSV infection (OR=1.672, P<0.05) were risk factors for severe CAP in children, while age was a protective factor (OR=0.475, P<0.01).

CONCLUSIONSRSV is the most frequent viral pathogen in children with severe CAP. The presence of underlying diseases and RSV infection may be risk factors for severe CAP, while age is a protective factor.

Child, Preschool ; Community-Acquired Infections ; virology ; Female ; Human bocavirus ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Logistic Models ; Male ; Pneumonia, Viral ; virology ; Respiratory Syncytial Viruses ; isolation & purification ; Risk Factors

OBJECTIVETo understand the clinical characteristics and outcome associated with respiratory syncytial virus (RSV) infection in hematopoietic stem cell transplantation (HSCT) recipients with primary immunodeficiencies (PIDs).

METHODNasopharyngeal aspirate samples were collected consecutively before and after HSCT from 9 recipients from Apr. 2009 to Sep. 2010 and analyzed for the presence of RSV using real-time polymerase chain reaction assay. To further verify the presence of the virus, positive samples for PCR were isolated for RSV. RSV G gene was amplified, sequenced and used for phylogenetic analysis.

RESULTThe presence of RSV was detected in 3 out of 9 children. The viral replication in all the patients was prolonged for months. All the 3 patients with RSV infection were treated with intravenous immune globulin (IVIG) and one was treated with antiviral medication. All patients survived and achieved successful immune reconstitution.

CONCLUSIONThis study indicates that the HSCT recipients with PID are at increased risk for RSV infection. RSV can shed for months after the initial infection and the patients recover with the course of immune reconstitution.

Child, Preschool ; Female ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Immunologic Deficiency Syndromes ; surgery ; virology ; Infant ; Prognosis ; Respiratory Syncytial Virus Infections ; diagnosis ; drug therapy ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; physiology ; Virus Replication ; Virus Shedding

Child ; Child, Preschool ; Computer Systems ; Humans ; Phylogeny ; Polymerase Chain Reaction ; methods ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; methods

OBJECTIVETo investigate the prevalence of viral infections and putative association of viral infection with illness severity in young children with severe lower respiratory tract infection (LRTI) in Chongqing.

METHODRespiratory secretion specimens were collected from 119 hospitalized patients with severe pneumonia from December 2006 to March 2008.After being processed, the samples were detected for respiratory viruses including respiratory syncytial virus (RSV), adenovirus (ADV), human metapneumovirus (hMPV), human bocavirus (HBoV), parainfluenza virus 1, 2, 3 (PIV 1, 2, 3), influenza virus A and B (IVA and IVB) either by PCR or RT-PCR. Clinical data were analyzed along with virological data by using appropriate statistical methods.

RESULTViral pathogens were identified in specimens of 86 (72.3%) cases, among which RSV was detected in 49 (41.2%) patients. More than one virus was detected in 23 individual (26.7%) samples, of which 19 were dual positive for RSV and another virus. Bacterial cultures were performed for 69 patients. Both bacterial and viral pathogens were identified in 53 (76.8%) patients. Bacterial and viral coinfection was demonstrated in samples from 41 (59.4%) cases.

CONCLUSIONViral pathogens are the main etiology of severe pneumonia in young children in Chongqing area during the study period. RSV was the most frequent viral pathogens, followed by ADV and hMPV. Coinfection with respiratory common viruses was relatively common, though co-infection with viruses did not appear to aggravate the patients' condition.

Adenoviridae ; isolation & purification ; Child, Preschool ; China ; epidemiology ; Human bocavirus ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Influenza A virus ; isolation & purification ; Metapneumovirus ; isolation & purification ; Pneumonia, Bacterial ; microbiology ; virology ; Pneumonia, Viral ; microbiology ; virology ; Respiratory Syncytial Viruses ; isolation & purification ; Virus Diseases ; virology

OBJECTIVEThe present study was designed to explore the practical application of the rapid etiological diagnosis by detecting specific IgM antibody against common respiratory viruses in children with acute lower respiratory infections (ALRI).

METHODClinical specimens including nasopharyngeal aspirates and serum of acute phase from hospitalized children were collected from 207 infants and children with acute lower respiratory infections from March 2009 to September 2010. Seven common respiratory virus antigens were identified from the collected nasopharyngeal aspirates by direct immunofluorescence assay (DFA). ELISA was used to detect specific IgM antibody against RSV, ADV, IFVA, IFVB and PIV, while indirect immunofluorescence assay (IFA) was used to detect specific IgM antibody against RSV, ADV, IFVA, IFVB, PIV1, PIV2 and PIV3 in collected acute phase serum.

RESULTThe overall positive rates to detect viral antigen by using DFA, ELISA and IFA was 67.6%, 57.5% and 39.6%, respectively. The consistent rate of ELISA and IFA versus accepted DFA were 21.7% and 31.4%, respectively. The average days from onset of the symptoms to blood sample collection for those with the consistent results by ELISA and DFA were 12.0 d for ADV, 9.6 d for PIV2, 9.5 d for IFV, and 5.3 d for RSV, respectively, and by IFA and DFA were 15.0 d for PIV3, 9.2 d for ADV, and 7.4 d for RSV, respectively. Among all age groups, the consistent rate of serum viral IgM and antigen detections was highest in children younger than 3 years old.

CONCLUSIONAlthough there were differences between serum IgM antibody and viral antigen detections, specific IgM antibody detection was of value in early and rapid etiological diagnosis of pediatric ALRI, especially for young children. It could provide serologic evidence of respiratory virus infection. The diagnostic rate of pathogen could be improved if it was used in combination with viral antigen diagnostic methods.

Antibodies, Viral ; analysis ; blood ; Antibody Specificity ; Antigens, Viral ; analysis ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Fluorescent Antibody Technique ; Humans ; Immunoglobulin M ; analysis ; blood ; Infant ; Male ; Nasopharynx ; virology ; RNA Viruses ; genetics ; isolation & purification ; Respiratory Syncytial Virus Infections ; diagnosis ; virology ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; Respiratory Tract Infections ; diagnosis ; immunology ; virology ; Sensitivity and Specificity