OBJECTIVETo establish the RT-PCR method to type the influenza virus.

METHODSAfter amplifying the virus by cell culture, we carried out RT-PCR by using two pairs typing primers and four pairs subtyping primers to detect the influenza virus.

RESULTSIn those 23 samples which had cytopathologic changes, there were 10 positive strains detected by RT-PCR assay including seven A type (six H3N2 subtype and one H1N1 subtype) and three B type.

CONCLUSIONThis method is rapid, specific and sensitive and possesses great value for practical application in the surveillance of influenza virus.

Humans ; Orthomyxoviridae ; classification ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; Sensitivity and Specificity

OBJECTIVETo study the clinical features and pathogens of plastic bronchitis in children.

METHODSA retrospective analysis was performed on the clinical data of 9 children who were diagnosed with plastic bronchitis between January 2011 and December 2012.

RESULTSPlastic bronchitis began with a fever and cough in all cases, followed by progressive dyspnea on days 1-3 of onset; unilateral or bilateral decreased breath sounds and hepatosplenomegaly were found; complications included respiratory failure (6 cases), toxic encephalopathy (6 cases), toxic hepatitis (7 cases), shock (3 cases), heart failure (3 cases), and renal failure (2 cases). Chest X-ray or chest CT showed single and multiple lobar or segmental consolidation and atelectasis, as well as pleural effusion (4 cases). The bronchofibroscopy revealed some grey-white mucus plugs that blocked bronchial openings and aspirates of bronchial shape. Influenza viruses (IFVs) were detected in all cases, including IFV-A (6 cases, 67%) and IFV-B (3 cases, 33%). Mixed infection with IFV-A and Mycoplasma pneumoniae (MP)/bacteria was found in 50% of all cases. In the three cases of IFV-B infection, one was complicated by MP infection. Nine patients were given treatment of antibiotics, hormones, gamma globulin and necessary respiratory support, and also were given removal of endogenous foreign body by bronchoscopy. Five patients were given antiviral therapy of oseltamivir. Seven cases cured, and 2 died.

CONCLUSIONSPlastic bronchitis and severe pneumonia are similar in clinical manifestations. IFVs are the main pathogen. In addition to anti-infection treatment, hormone, gamma globulin, respiratory support, and other conventional treatments, endogenous foreign body removal by bronchofibroscopy and early antiviral therapy with oseltamivir have good efficacy.

Bronchitis ; diagnosis ; drug therapy ; etiology ; pathology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Orthomyxoviridae ; isolation & purification

Animals ; Humans ; Influenza, Human ; virology ; Orthomyxoviridae ; genetics ; isolation & purification ; Orthomyxoviridae Infections ; epidemiology ; veterinary ; virology ; Swine ; Swine Diseases ; virology ; Viral Proteins ; genetics

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

OBJECTIVETo investigate the nonbacterial pathogens in children with acute respiratory infection (ARI) in Nanjing.

METHODSThe presence of Mycoplasma pneumoniae (MP) and Chlamydia trachomatis (CT) was determined by quantitative PCR in the nasopharyngeal samples from 1 592 hospitalized children with ARI. Common respiratory viruses, including respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus types A and B (IVA and IVB), parainfluenza virus types 1, 2, 3(PIV-1, 2, 3) and human metapneumovirus (hMPV), were detected using direct immunofluorescence assay.

RESULTSMP and CT were detected in 25.7% and 2.4% of the 1 592 samples respectively. The overall positive rate of respiratory viruses was 40.9%. Among the viruses, the top detected virus was RSV (61.3%), followed by PIV-3 (6.7%) and hMPV (4.9%). Mixed infection among MP, CT and viruses was observed in 107 cases (6.7%). The infants under 1 year old were susceptible to mix-infection (68/107, 63.6%).

CONCLUSIONSRespiratory virus is the main pathogen responsible for ARI in children from Nanjing. RSV is the most commonly identified virus. MP is also the frequently identified pathogen for ARI in children. Mixed infection is common in infants under 1 year old.

Adenoviruses, Human ; isolation & purification ; Adolescent ; Child ; Child, Preschool ; Chlamydia trachomatis ; isolation & purification ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Metapneumovirus ; isolation & purification ; Mycoplasma pneumoniae ; isolation & purification ; Orthomyxoviridae ; isolation & purification ; Respiratory Syncytial Virus, Human ; isolation & purification ; Respiratory Tract Infections ; microbiology ; virology

A novel H17N10 subtype of the influenza A viruses was found in bats in 2012. Protein sequence and structural analyses revealed that the HA17 and NA10 proteins of this strain are different from corresponding ones in known influenza A subtype viruses. Both HA17 and NA10 proteins cannot bind to sialic acid,which indicates that they may have novel functions. This article briefly describes the state of current research into the H17N10 subtype of bat influenza A virus.
Animals ; Chiroptera ; virology ; Influenza A virus ; classification ; genetics ; isolation & purification ; metabolism ; Orthomyxoviridae Infections ; veterinary ; virology ; Viral Proteins ; genetics ; metabolism

OBJECTIVETo investigate the viral pathogens of acute lower respiratory tract infection (ALRTI) in hospitalized children from East Guangdong Province of China and the relationship of the pathogens with age and seasons.

METHODSThe nasopharyngeal aspirates samples obtained from 345 hospitalized children with ALRTI were investigated for respiratory syncytial virus (RSV), human bocavirus (HBoV), human metapneumovirus (hMPV), influenza virus types A and B, rhinovirus, parainfluenza virus types 1 and 3 and adenovirus by PCR.

RESULTSViral pathogens were detected in 178 patients (51.6%). RSV was the most frequent (19.3%). Novel viruses hMPV (3.2%) and HBoV (3.2%) were found. A highest detection rate (61.9%) of virus was found between January to March. The infants aged 1 to 6 months showed a higher detection rate (71.3%) of virus than the other age groups. The detection rate of viral pathogens was 72.6% in children with bronchiolitis, followed by asthmatic bronchitis (70.0%) and bronchial pneumonia (44.6%).

CONCLUSIONSRSV remained the leading viral pathogens in children with ALRTI in East Guangdong of China. Novel viruses HBoV and hMPV were also important pathogens. The detection rate of viral pathogens was associated with seasonal changes and age. Different respiratory infectious diseases had different viral detection rates, with highest detection rate in bronchiolitis cases.

Acute Disease ; Adenoviridae ; isolation & purification ; Child, Hospitalized ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Metapneumovirus ; isolation & purification ; Nasopharynx ; virology ; Orthomyxoviridae ; isolation & purification ; Respiratory Syncytial Virus, Human ; isolation & purification ; Respiratory Tract Infections ; virology ; Rhinovirus ; isolation & purification ; Seasons

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

A GeXP based multiplex RT-PCR assay was developed to simultaneously detect twelve different respiratory viruses types/subtypes including influenza A virus, influenza B virus, influenza A virus sH1N1, parainfluenza virus type 1, parainfluenza virus type 2, parainfluenza virus type 3, human rhinovirus, human metapneumovirus, adenovirus, respiratory syncytial virus A, respiratory syncytial virus B and human bocavirus. Twelve sets of specific primers were designed based on the conserved sequences of available respiratory-virus sequence database. The specificity of the multiplex system was examined by positive specimens confirmed previously. The sensitivity to detect twelve respiratory viruses simultaneously was 10(3) copies/microL. Twenty four clinical specimens were further detected by this novel assay and the results were compared with that of the real-time RT-PCR. These results showed that this novel assay based on GeXP is a fast, sensitive, and high throughput test for the detection of respiratory virus infections.
Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; isolation & purification ; Orthomyxoviridae ; genetics ; isolation & purification ; Orthomyxoviridae Infections ; virology ; RNA Viruses ; genetics ; isolation & purification ; Real-Time Polymerase Chain Reaction ; instrumentation ; methods ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; Respiratory Tract Infections ; virology ; Reverse Transcriptase Polymerase Chain Reaction ; instrumentation ; methods ; Rhinovirus ; genetics ; isolation & purification ; Sensitivity and Specificity

PURPOSE: Early identification of causative agents in lower respiratory infection of pediatric patients can reduce morbidity and prevent an overuse of antimicrobials. Two kinds of multiplex polymerase chain reaction (PCR) and a commercial shell vial viral culture were performed to identify causative agents in pediatric patients. MATERIALS AND METHODS: Nasopharyngeal aspirates of 220 children diagnosed with viral pneumonia were obtained. Two kinds of multiplex PCR (Seeplextrade mark RV detection kit, and Labopasstrade mark RV detection kit), and a shell vial culture by R-Mix were performed. RESULTS: Positive samples from 220 total samples by two multiplex PCRs were 52.7% and 46.4%, respectively. We also cultured 103 samples that showed positive results of the adenovirus, influenza virus, parainfluenza virus, and respiratory syncytial virus (RSV) by two multiplex PCR. The RSV was most frequently detected in 53.0% (Seeplex) and 51.7% (Labopass) of patients. The detection rate of adenovirus (AdV) was 10.3% and 12.1%, influenza virus (IFV) A and B was 12.5% and 3.4%, and parainfluenza virus (PIFV) 1, 2, and 3 were 2.9% and 2.6%. Shell vial cultures showed concordant results with each multiplex PCR by 96.1% and 77.7%, respectively. Sequencing results were 90% consistent with multiplex PCR. CONCLUSION: Multiplex PCR showed more positivity than the shell vial culture and it can be an effective primary test. Other complementary efforts such as viral cultures and sequencing analysis could be considered, according to clinical and laboratory conditions.
Adenoviridae/genetics/*isolation & purification ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Orthomyxoviridae/genetics/*isolation & purification ; Pneumonia, Viral/*virology ; Polymerase Chain Reaction/*methods ; Respiratory Syncytial Viruses/genetics/*isolation & purification ; Respirovirus/genetics/*isolation & purification