Human parainfluenza viruses (HPIVs) is one of the main causes of acute respiratory tract infections in children. HPIVs have been grouped into four serotypes (HPIV1~HPIV4) according to serological and genetic variation. Different serotypes of HPIVs have diverse clinical disease spectrum, epidemic characteristics and disease burden. Based on the nucleotide variation in structural protein genes, HPIVs can be further divided into distinct genotypes and subtypes with diverse temporal and spatial distribution features. The standard molecular typing methods are helpful to clarify the gene evolution and transmission patterns of HPIVs in the process of population transmission. However, the development of molecular epidemiology of HPIVs has been hindered by the lack of a standardized molecular typing method worldwide. Therefore, this study reviewed the viral characteristics, genome structure, existing genotyping methods and evolution of HPIVs, and screened the reference strains for molecular typing, so as to improve the understanding of gene characteristics and molecular typing of HPIVs, and provide an important scientific basis for the monitoring and research of molecular epidemiology of HPIVs in China.
Child ; Humans ; Molecular Typing ; Parainfluenza Virus 1, Human/genetics* ; Parainfluenza Virus 2, Human/genetics* ; Parainfluenza Virus 3, Human/genetics* ; Paramyxoviridae Infections/epidemiology* ; Respiratory Tract Infections/epidemiology*

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.
Child ; Child, Preschool ; Cross-Sectional Studies ; Female ; Hemagglutinins ; Humans ; Neuraminidase ; Parainfluenza Virus 3, Human/genetics* ; Phylogeny ; Respiratory Tract Infections/epidemiology* ; Viral Proteins

PURPOSE: Croup is a common respiratory disease in children. The aim of this study was to analyze the epidemiology, etiology, and seasonal variations of respiratory virus infections in children with croup. METHODS: From October 2009 to September 2017, children admitted with croup to Gachon University Gil Medical Center under the age of 18 years were enrolled in this study. We retrospectively reviewed patients' medical records. RESULTS: A total of 1,053 of 27,330 patients (3.9%) infected with lower respiratory infections were diagnosed as having croup. In the age distribution, croup was most common (50.0%) in children aged 1 to <2 years. There were 2 peaks, the major in summer (July to August) and the minor in spring (March to May). Parainfluenza virus type 1 (15.8%) was most prevalent and coincided with the summer peaks of croup. Influenza virus type B and parainfluenza virus type 3 were the most frequent etiologic agents in a spring peak of croup. Although parainfluenza virus type 1 was predominant of all ages, human coronavirus was a significant cause of croup in children younger than 1 year, whereas influenza virus played an important role in children above the age of 3 years. CONCLUSION: Seasonality and epidemiology of croup varied with age and regions. Two peaks of seasonal fluctuation were in summer and spring, which were related to the seasonality of respiratory viruses in croup. These results may be helpful in planning clinical and research needs.
Age Distribution ; Child ; Coronavirus ; Croup* ; Epidemiology ; Humans ; Medical Records ; Orthomyxoviridae ; Parainfluenza Virus 1, Human ; Parainfluenza Virus 3, Human ; Respiratory System* ; Respiratory Tract Infections* ; Retrospective Studies ; Seasons*

PURPOSE: Croup, a common childhood respiratory illness with various severities, has many unanswered questions. Laryngotracheobronchopneumonitis (LTBP) is a disease entity considered to be an extension of croup to the lower respiratory tract. The object of this study was to compare epidemiology, clinical characteristics, and viral etiologic spectrum between croup and LTBP. METHODS: Patients hospitalized with croup at Gachon University Gil Hospital from January 2010 to April 2016 were recruited. LTBP was defined as pneumonia confirmed on radiographs of patients with croup. Clinical findings and demographic data were reviewed of patients whose nasopharyngeal swabs were done for viral analysis. RESULTS: A total of 371 patients with only croup and 63 patients with LTBP were included. Croup was found to be significantly associated with parainfluenza virus type 1 (P=0.006). LTBP was related to parainfluenza virus type 3, respiratory syncytial virus, and human bocavirus (P=0.001, P=0.030, and P=0.019, respectively). The duration of fever was longer in patients with LTBP than in those with croup (3.87±1.85 days vs. 2.86±1.80 days, P<0.001). CONCLUSION: Specific etiologic viruses might be associated with the progression from croup to LTBP. Pronged fever is also associated with progression from croup to LTBP.
Child* ; Croup* ; Epidemiology ; Fever ; Human bocavirus ; Humans ; Parainfluenza Virus 1, Human ; Parainfluenza Virus 3, Human ; Pneumonia ; Respiratory Syncytial Viruses ; Respiratory System

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 determine the level of genetic variation of human parainfluenza virus type 3 (HPIV-3), and to describe infection and co-infection characteristics of HPIV-3 in children.

METHODSSingle respiratory samples from 856 pediatric patients with acute respiratory tract infection (ARI) in Hangzhou were collected from December 2009 to March 2013. All samples were screened for HPIV-3 by real-time RT-PCR and followed by HN sequencing and phylogenetic analysis. In all RSV positive specimens, we screened for the other pathogens, and co-infection characteristics were evaluated.

RESULTSA total of 9.6% of 856 samples were positive for HPIV-3, the nucleotide among the strains ranged from 96.9% to 100%. All Hangzhou strains were placed in C3 subgroup based on HN gene analysis. 49% (n=41) of all HPIV-3-positive children with ARI were found to be co-infected with at least one of the other pathogen. The highest co-infection rate of HPIV-3 was with HRV (n=17). Children in the younger groups (≤12 months old) were significantly more prone to be co-infected with other pathogen (χ(2)=4.78, P=0.029). Pneumonia infection rate was significantly higher in the mono-infection group than the co-infection group (χ(2)=3.92, P=0.048).

CONCLUSIONHPIV-3 was an important pathogen in children with ARI in Hangzhou. HN gene variation rate was low, but showed a more local pattern. The co-infections with other respiratory viruses were popular. Except for pneumonia, no significant differences in other clinical presentation between the HPIV-3 mono-infection and co-infection groups were observed.

Child ; China ; epidemiology ; Genetic Variation ; Humans ; Parainfluenza Virus 3, Human ; Phylogeny ; Real-Time Polymerase Chain Reaction ; Respiratory Tract Infections ; epidemiology ; virology ; Respirovirus Infections ; epidemiology

BACKGROUNDAlthough human parainfluenza virus (HPIV) has been determined as an important viral cause of acute respiratory infections (ARIs) in infants and young children, data on long-term investigation are still lacking to disclose the infection pattern of HPIV in China.

METHODSNasopharyngeal aspirates were collected from 25,773 hospitalized pediatric patients with ARIs from January 2004 through December 2012 for respiratory virus screen by direct immuno-fluorescence assay.

RESULTSOut of these specimens, 1675 (6.50%, 1675/25,773) showed HPIV positive, including 261 (1.01%, 261/25,773) for HPIV1, 28 (0.11%, 28/25,773) for HPIV2, and 1388 (5.39%, 1388/25,773) for HPIV3, 2 of the samples were positive for both HPIV1 and HPIV3, and 36 were co-detected with other viruses. The positive rates of HPIVs were higher in those younger than 3 years old. HPIV3 was detected from all age groups, predominantly from patients under 3 years of age, and the highest frequency was found in those 6 months to 1-year old (352/4077, 8.63%). HPIV3 was the dominant type in each of the years detected between May and July. HPIV1 showed a peak in every odd year, mainly in August or September. HPIV was detected most frequently from patients with upper respiratory infection (12.49%, 157/1257), followed by bronchitis (11.13%, 176/2479), asthma (9.31%, 43/462), bronchiolitis (5.91%, 150/2536), pneumonia (6.06%, 1034/17,068), and those with underlying diseases (1.0%, 15/1506). HPIV3 is the dominant type in these six disease groups referred above, especially in the asthma group.

CONCLUSIONSHPIV is one of the important viral causes of ARIs in infants and young children in Beijing based on the data from the hospitalized children covering a 9-year term. HPIV3 is the predominant type in all these years and in most of the disease groups. HPIVs with different types show different seasonality.

Beijing ; epidemiology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Parainfluenza Virus 1, Human ; pathogenicity ; Parainfluenza Virus 3, Human ; pathogenicity ; Respirovirus ; pathogenicity ; Respirovirus Infections ; diagnosis ; virology

To investigate the genetic characterization of Human parainfluenza virus-3 (HPIV-3) circulating in Gansu and Shaanxi Provinces of China, 719 throat swabs were collected from pediatric patients with acute respiratory infections from 2009-2011. Multiplex RT-PCR was used to screen common respiratory viral pathogens. For HPIV-3-positive specimens, nested RT-PCR was used to amplify the HN gene of HPIV-3. The nucleotides of Hemagglutinin-neuraminidase(HN)gene of 13 HPIV-3 positive strains identified in Gansu and Shaanxi Provinces were successfully sequenced and compared with those downloaded from GenBank. The phylogenetic analysis based on the nucleotides sequence of HN gene showed that 13 HPIV-3 strains belonged to sub-cluster C3 with little sequence variation (overall nucleotide divergence of 0.2%-2.3% and amino acid divergence at 0-1.1%). Compared with the complete gene of HPIV-3 strains from U.S.A., Canada, and Australia, the biggest divergence of the nucleotide and amino acid lovels was 6.0% and 3.4%, respectively. The nucleotide divergence between shaanxi09-2 and shaanxi10-H0091 was 0.9%, while the nucleotide divergence between shaanxi10-H005 and gansull-62110372 was 0.5%, between shaanxi09-2 and BJ/291/09 was 0.6%. However, there was no amino acid divergence among them. It is likely that HPIV-3 virus had been transmitting in Gansu and Shaanxi Provinces for several years. Human parainfluenza virus-3 (HPIV-3) circulated in Gansu and Shaanxi Provinces from 2009 to 2011 belonged to sub-cluster C3.
Adolescent ; Adult ; Child ; China ; epidemiology ; Female ; Genetic Variation ; HN Protein ; genetics ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Parainfluenza Virus 3, Human ; classification ; genetics ; isolation & purification ; Phylogeny ; Respirovirus Infections ; epidemiology ; virology ; Seasons ; Young Adult

To determine the functions of N-carbohydrate chains in human parainfluenza virus type 3 hemagglutinin-neuraminidase(HN) protein, a PCR-based site-directed mutagenesis method was used to obtain N-glycan mutants. Protein electrophoresis rate, cell surface expression,receptor binding activity, neuraminidase activity and cell fusion promotion activity were determined. The HN proteins of single mutants (G1, G2, and G4) and multiple mutants (G12, G14, G24 and G124) migrated faster than the wild-type (wt) HN protein on polyacrylamide gels, while G3-mutated protein and wt HN protein migrated at the same position. There was no statistic difference in cell surface expression and neuraminidase activity between wt and each mutant HN protein (P>0.05), but receptor binding activity and cell fusion promotion activity of each mutant protein was reduced to significant extent (P<0.05). G1, G2 and G4 mutants exhibited re duced receptor binding activity, which was 83.94%, 76.45% and 55.32% of the wt level, respectively. G1, G2 and G4-mutated proteins also showed reductions in fusion promotion activity, which was 80.84%, 77.83% and 64.16%, respectively. Multiple mutants with G12-, G14-, G24- and G124- substitutions could further reduce receptor binding activities, 33.07%, 20.67%, 19.96% and 15.11% of the wt HN level, respectively. G12, G14, G24 and G124 mutants exhibited levels of fusion promotion activity that were only 46.360, 12.04%, 13.43% and 4.05% of the wt amount, respectively. As N-glycans of hPIV3 HN protein play an important role in receptor binding activity and cell fusion promotion activity of HN protein. We propose that the loss of N-glycans change the conformation or orientation of globular domain that is responsible for receptor binding and lower receptor binding activity and cell fusion promotion activi ty.
Glycosylation ; HN Protein ; chemistry ; genetics ; metabolism ; Humans ; Mutation ; Parainfluenza Virus 3, Human ; chemistry ; enzymology ; genetics ; physiology ; Protein Binding ; Receptors, Virus ; metabolism ; Respirovirus Infections ; metabolism ; virology ; Virus Internalization

This study was performed to characterize respiratory viral infections in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Study samples included 402 respiratory specimens obtained from 358 clinical episodes that occurred in the 116 children of the 175 consecutive HSCT cohort at Seoul National University Children's Hospital, Korea from 2007 to 2010. Multiplex reverse-transcription polymerase chain reactions were performed for rhinovirus, respiratory syncytial virus (RSV), parainfluenza viruses (PIVs), adenovirus, human coronavirus (hCoV), influenza viruses and human metapneumovirus. Viruses were identified in 89 clinical episodes that occurred in 58 patients. Among the 89 clinical episodes, frequently detected viruses were rhinovirus in 25 (28.1%), RSV in 23 (25.8%), PIV-3 in 16 (18.0%), adenovirus in 12 (13.5%), and hCoV in 10 (11.2%). Lower respiratory tract infections were diagnosed in 34 (38.2%). Neutropenia was present in 24 (27.0%) episodes and lymphopenia was in 31 (34.8%) episodes. Sixty-three percent of the clinical episodes were hospital-acquired. Three patients died of respiratory failure caused by respiratory viral infections. Respiratory viral infections in pediatric patients who have undergone HSCT are common and are frequently acquired during hospitalization. Continuous monitoring is required to determine the role of respiratory viruses in immunocompromised children and the importance of preventive strategies.
Adenoviridae/genetics/isolation & purification ; Adolescent ; Adult ; Child ; Child, Preschool ; Cohort Studies ; Coronavirus/genetics/isolation & purification ; Female ; *Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells/cytology ; Hospitalization ; Humans ; Infant ; Lymphopenia/epidemiology ; Male ; Neutropenia/epidemiology ; Parainfluenza Virus 3, Human/genetics/isolation & purification ; Prevalence ; Respiratory Syncytial Viruses/genetics/isolation & purification ; Respiratory Tract Infections/epidemiology/therapy/*virology ; Reverse Transcriptase Polymerase Chain Reaction ; Rhinovirus/genetics/isolation & purification ; Seasons ; Young Adult