Detection of respiratory pathogens and clinical features in 225 children with acute exacerbation of bronchial asthma / 中国当代儿科杂志

OBJECTIVE@#To investigate the respiratory pathogens and clinical features in children with acute exacerbation of bronchial asthma.@*METHODS@#Nasopharyngeal swabs were collected from 225 children with acute exacerbation of bronchial asthma, aged <14 years, who attended the outpatient service or were hospitalized from August 2017 to August 2019. Quantitative real-time PCR was used to detect 12 pathogens, i.e., respiratory syncytial virus (RSV), human rhinovirus (HRV), influenza virus A (IFVA), influenza virus B (IFVB), parainfluenza virus types 1-3 (PIV1-3), human metapneumovirus (HMPV), adenovirus (ADV), Bordetella pertussis (BP), Chlamydia pneumoniae (CP), and Mycoplasma pneumoniae (MP).@*RESULTS@#The overall detection rate of virus was 46.2% (104/225), and 7 kinds of viruses were detected, i.e., HRV (19.6%, 44/225), ADV (16.0%, 36/225), IFVB (5.8%, 13/225), RSV (4.9%, 11/225), IFVA (3.6%, 8/225), PIV3 (1.8%, 4/225), and HMPV (0.4%, 1/225). Of all pathogens, BP had the highest detection rate of 28.4% (64/225), and the detection rates of MP and CP were 16.4% (37/225) and 0.4% (1/225), respectively. The mild exacerbation group had a higher detection rate of BP than the severe exacerbation group (P<0.05), while the severe exacerbation group had significantly higher detection rates of RSV and MP than the mild exacerbation group (P<0.05). There were significant differences in the proportion of children with paroxysmal cough, spasmodic cough, fever, lung rales and abnormal lung imaging findings among the simple BP infection, simple virus infection and simple MP infection groups (P<0.05).@*CONCLUSIONS@#BP, HRV, and MP are common respiratory pathogens detected in children with acute exacerbation of bronchial asthma, and respiratory virus infection is an important pathogen of acute exacerbation of asthma in children. Acute exacerbation of asthma caused by different pathogens has different clinical features and severities.

Relationship between viral load of human bocavirus and clinical characteristics in children with acute lower respiratory tract infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of human bocavirus (HBoV) in children with acute lower respiratory tract infection and to explore the relationship between the viral load of HBoV and the clinical characteristics of acute lower respiratory tract infection in children.</p><p><b>METHODS</b>A total of 1 554 nasopharyngeal aspirates from children who were hospitalized due to acute lower respiratory tract infection between March 2011 and March 2014 were collected. Quantitative real-time PCR was used to detect 12 RNA and 2 DNA viruses, adenovirus (ADV) and HBoV, and to measure the viral load of HBoV in HBoV-positive children. A comprehensive analysis was performed with reference to clinical symptoms and indicators.</p><p><b>RESULTS</b>In the 1 554 specimens, 1 212 (77.99%) were positive for viruses, and 275 (17.70%) were HBoV-positive. In HBoV-positive cases, 94.9% were aged <3 years, and there were more males than females. In the 275 HBoV-positive cases, 45 (16.36%) had single infection, and 230 (83.64%) had mixed infection. There was no significant difference in viral load between children with single infection and mixed infection (P>0.05). The patients with fever had a significantly higher viral load than those without fever (P<0.05). The children with wheezing had a significantly higher viral load than those without wheezing (P<0.05). There was no significant difference in viral load between children with mild, moderate, and severe acute lower respiratory tract infection (P>0.05).</p><p><b>CONCLUSIONS</b>HBoV is one of the important pathogens of acute lower respiratory tract infection in children. Children with a higher viral load of HBoV are more likely to experience symptoms such as fever and wheezing. However, the severity of disease and mixed infection are not significantly related to viral load.</p>

Viral etiology in children with acute lower respiratory tract infections plus platelet disorders in Changsha, China: an analysis of 255 cases / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the viral etiology in hospitalized children with acute lower respiratory tract infections (ALRTI) plus platelet disorders.</p><p><b>METHODS</b>A total of 255 children with ALRTI plus platelet disorders and 442 children with ALRTI and normal platelets, all of whom were hospitalized between March 2010 and February 2011, were included in the study. Their nasopharyngeal aspirate samples were collected, and RT-PCR or PCR was performed to detect 14 viruses.</p><p><b>RESULTS</b>Of 255 ALRTI patients with platelet disorders, thrombocytosis was found in 253 cases (99.2%) and thrombocytopenia in 2 cases (0.8%). Among ALRTI patients with platelet disorders, 173 (67.8%) were infected with at least one virus, with human rhinovirus as the most common one, followed by parainfluenza virus type 3 (PIV3) and respiratory syncytial virus (RSV). The detection rate of PIV3 in the abnormal platelet group was significantly higher than in the normal platelet group (P<0.05). In contrast, the detection rate of influenza virus B (IFVB) in the abonormal platelet group was significantly lower than in the normal platelet group (P<0.05). The age distribution showed significant difference between the abnormal and normal platelet groups (P<0.01). Platelet disorders were mainly found in children under one year of age (P<0.01).</p><p><b>CONCLUSIONS</b>Thrombocytosis is often found in children with ALRTI caused by viruses, especially PIV3, but infection with IFVB seldom causes platelet disorders. Hospitalized children with ALRTI under one year tend to develop platelet disorders.</p>

Virus detection in bronchoalveolar lavage fluid of 122 children with severe pneumonia / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of viral pathogen in children with severe pneumonia in Hunan.</p><p><b>METHOD</b>Bronchoalveolar lavage fluid [BALF] were collected from 122 hospitalized children with severe pneumonia in People's Hospital of Hunan province from January 2011 to December 2011. Nested- or reverse transcription Polymerase chain reaction (PCR or RT-PCR) was used to screen Adenovirus (ADV), Human Bocavirus (HBoV), Parainfluenzaviruses1-4 (PIV1-4), Human Respiratory Syneytial virus (RSV), Influenza virus A (IFVA), Influenza virus B (IFVB), Human Rhinovirus(HRV), Human Metapneumovirus (HMPV), human coronaviruses NL63 and HKU1 (HCoV-NL63, HCoV- HKU1).</p><p><b>RESULTS</b>Among the 122 bronchoalveolar lavage fluid, viral agents were detected in 60 samples(49.1%), among which ADV (40.98%) was the most common virus, followed by RSV (7.37%) and HBoV (7.37%). Two viruses were detected in 21 individual (35%) samples, of which 20 were dual positive for ADV (40%).</p><p><b>CONCLUSION</b>ADV is the most frequently detected viral etiology of severe pneumonia in children in Hunan during this year. And its Coinfection with other respiratory viruses was common.</p>

Establishment and clinical application of TapMan real-time RT-PCR method for detection of HHV-6 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a rapid, sensitive and specific real-time PCR method for detection of Human Herpesvirus-6 (HHV-6).</p><p><b>METHODS</b>According to the reference, a pair of primers and a probe were designed located in U65-66 gene and to set up the standards. We established a real-time RT-PCR method for detection of HHV-6, and to verify the specificity, sensitivity, reproducibility.</p><p><b>RESULTS</b>The correlation coefficient was 0.999, E = 97.9%, the coefficient of variation values of Ct were 0.61% and 3.13% in real-time PCR assay for inter and intra assay, respectively. The results of all viruses were negative except of HHV-6 for the assay. The quantitative detection limit of the assay was 3 x 10(0) copies/microl.</p><p><b>CONCLUSION</b>The real-time PCR assay is highly specific, sensitive and reproducible, which can be used to quatitative detecting clinical samples.</p>

Status of enterovirus infection in children with acute lower respiratory tract infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the status of enterovirus (EV) infection in children with acute lower respiratory tract infection (ALRTI).</p><p><b>METHODS</b>A total of 404 samples (with odd numbers) of nasopharyngeal aspirates were collected from the children who were hospitalized in the Children's Medical Center, Hunan Provincial People's Hospital due to ALRTI between September 2007 and April 2008. The conserved sequence in the 5'-noncoding region of EV was used to design the primer, and nested RT-PCR was performed to detect EV in the samples.</p><p><b>RESULTS</b>Of the 404 samples, 19 (4.7%) were EV-positive, and mostly taken from children under 3 years of age (95%); there was no significant difference in the detection rate between male and female children. Of the EV-positive children, 13 (68%) were clinically diagnosed with bronchial pneumonia, and 6 (32%) with bronchiolitis; 90% of them showed symptoms of fever, 84% had a cough, 63% had asthma, and 63% had complications mainly including diarrhea (6 cases), granulocytopenia (4 cases), and acute respiratory distress syndrome (2 cases). In addition, 26% of the EV-positive children had leukocyte disorder, more than half had liver dysfunction, and a few had myocardial involvement.</p><p><b>CONCLUSIONS</b>EV is a pathogen that should not be neglected in children with ALRTI. For these children, close attention should be paid to the epidemiological status and clinical features of EV infection, and blood routine examination, liver function test and myocardial enzyme assay should be carried out periodically to improve prognosis.</p>

Viral etiology and risk factors for severe community-acquired pneumonia in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the virus spectrum of severe community-acquired pneumonia (CAP) and risk factors for the disease in children.</p><p><b>METHODS</b>Respiratory 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.</p><p><b>RESULTS</b>Viral 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).</p><p><b>CONCLUSIONS</b>RSV 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.</p>

Viral etiology of 1165 hospitalized children with acute lower respiratory tract infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the viral etiology of acute low respiratory tract infection (ALRTI) among hospitalized children in Changsha of Hunan Province of China.</p><p><b>METHODS</b>Nasopharyngeal aspirates were collected from 1165 hospitalized children with ALRTI in Changsha from September 2007 to August 2008. Respiratory syncytin virus (RSV), human rhinovirus (HRV), influenza virus A (IFVA), influenza virus B (IFVB), parainfluenza 1-3 (PIV 1-3), human metapneumovirus (hMPV), human coronaviruses NL63 (HCoV-NL63), and human coronaviruses HKU1 (HCoV-HKU1) were detected by reverse transcription polymerase chain reaction (RT-PCR). Adenovirus (ADV) and human bocavirus (HBoV) were detected by standard polymerase chain reaction (PCR). WU polyomaviruses (WUPyV) and KI polyomaviruses(KIPyV) were detected by nested PCR. The positive samples further underwent genetic sequencing.</p><p><b>RESULTS</b>Among the 1165 nasopharyngeal aspirates, viruses were detected in 871 samples (74.76%), among which RSV (27.03%) was the most common virus, followed by HRV (17.33%), PIV3 (13.73%), HBoV (8.67%) and hMPV (6.52%). The overall positive rate of viral detection showed no significant differences between males and females (X2=2.241, P=0.134), whereas the positive rates of PIV3, hMPV, and HBoV in males were higher than in females. The positive rate of viral detection showed significant differences among different age groups (X2=10.934, P=0.027), and the highest positive rate was noted in the age group of 6 months to 1 year. Furthermore, the overall positive rate of viral detection showed a significant difference in term of seasonal distribution, with a peak prevalence in winter.</p><p><b>CONCLUSIONS</b>Virues predominate in the etiology of pediatric ALRTI in Changsha, and RSV, HRV and PIV3 are the main viruses for ALRTI. HBoV and hMPV have become increasingly important. Viral infection-associated ALRTI shows a prevail in the age group of 6 months to 1 year as well as in winter.</p>

Molecular epidemiological and clinical feature of human metapneumovirus in children with acute lower respiratory tract infection in Changsha area from 2007 to 2011 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the epidemiological characteristics of human metapneumovirus (hMPV) infection in children with acute lower respiratory tract infection (ALRTI) in Changsha area, China.</p><p><b>METHODS</b>A total of 2613 nasopharyngeal aspirate (NPA) specimens were collected from hospitalized children with ARTIs between September 2007 and February 2011 (a period of 3.5 years) in Changsha area, Hunan Province, China. Respiratory specimens were screened for hMPV M gene by reverse-transcription polymerase chain reaction (RT-PCR). All RT-PCR positive' amplification products were confirmed by sequencing or analyzed and compared with those in GenBank known hMPV reference strain.</p><p><b>RESULTS</b>hMPV was detected in 135 (5.2%) out of the 2613 children. The detected rate was significantly different between male and female (chi2 = 8.007, P = 0.003). The majority of the hMPV-positive patients (63.2%) were 0-1 year old infants. The majority of hMPV-positive patients were detected during spring season. Seasonal distribution showed that subtype A2b circulated predominantly in winter and spring, subtype B2 circulated predominantly in summer and spring. The most common genotype in 135 hMPV-positive patients were A and B in human subjects in Changsha. The predominant genotype of hMPV changed over the 3.5 year study period from genotype A2b to combined A2b and B2, and to B2. The 66 (48.9%) out of the 135 hMPV-positive patients were found to be co-infected with other respiratory viruses, and human bocavirus (HBoV) was the most common additional respiratory virus.</p><p><b>CONCLUSION</b>These data suggest that some cases of acute lower respiratory infection in young children in Changsha area are related to hMPV and the majority of children infected with hMPV were less than 1 years old, the detected rate of boys was higher than that of girls. It circulated predominantly in spring. The subtype A2b genetic lineage and the subtype B1 genetic lineage of hMPV were revealed alternately in human subjects in Changsha area and the hMPV exhibited high co-infection rate with other respiratory viruses.</p>

Detection and clinical study on coronavirus HKU1 with acute lower respiratory tract infections of hospitalized children in Changsha / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>In order to understand the epidemiological and virologic characteristics of coronavirus HKU1 infection in hospitalized children with acute respiratory tract infection (ARTI) in Changsha.</p><p><b>METHODS</b>1165 nasopharyngeal aspirates (NPA) specimens were collected from hospitalized children with ARTI between September 2007 and August 2008 in Changsha. Specimens were screened for pol gene of coronavirus HKU1 by polymerase chain reaction. All positive amplification products were confirmed by sequencing and compared with those in GenBank.</p><p><b>RESULTS</b>Coronavirus HKU1 were detected in 12 patients (1.03%) out of the 1165 children. The patients were from 8 days to 3 years. The most common clinical diagnosis was bronchopneumonia(83.33%). Similarity of coronavirus HKU1 with those published in the GenBank at nucleotide levels was 98.18% - 100%.</p><p><b>CONCLUSION</b>Coronavirus HKU1 may be important pathogens in children with acute lower respiratory tract infection. Coronavirus HKU1 infections are common in children under 3 years old. There is no significant difference in the infectious rate between the boys and the girls. The peak of its prevalence is in spring and winter. A single genetic lineage of Coronavirus HKU1 was revealed in human subjects in Changsha.</p>