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>

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>

Prevalence and clinical characteristics of coronavirus NL63 infection in children hospitalized for acute lower respiratory tract infections in Changsha / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>The main objective of this study was to explore the prevalence and clinical characteristics of human coronavirus NL63 infection in hospitalized children with acute lower respiratory tract infection (ALRTI) in Changsha.</p><p><b>METHODS</b>Nasopharyngeal aspirates (NPA) samples were collected from 1185 hospitalized children with ALRTI at the People's Hospital of Hunan province, between September 2008 and October 2010. Reverse transcriptase polymerase chain reaction (RT-PCR) was employed to screen for coronavirus NL63, which is a 255 bp fragment of a part of N gene. All positive amplification products were confirmed by sequencing and compared with those in GenBank.</p><p><b>RESULTS</b>The overall frequency of coronavirus NL63 infection was 0.8%, 6 (60%) out of the coronavirus NL63 positive patients were detected in summer, 2 in autumn, 1 in spring and winter, respectively. The patients were from 2 months to two and a half years old. The clinical diagnosis was bronchopneumonia (60%), bronchiolitis (30%), and acute laryngotracheal bronchitis (10%). Four of the 10 cases had critical illness, 4 cases had underlying diseases, and 7 cases had mixed infection with other viruses. The homogeneity of coronavirus NL63 with those published in the GenBank at nucleotide levels was 97%-100%.</p><p><b>CONCLUSION</b>Coronavirus NL63 infection exists in hospitalized children with acute lower respiratory tract infection in Changsha. Coronavirus NL63 infections are common in children under 3 years of age. There is significant difference in the infection rate between the boys and the girls: the boys had higher rate than the girls. The peak of prevalence of the coronavirus NL63 was in summer. A single genetic lineage of coronavirus NL63 was revealed in human subjects in Changsha. Coronavirus NL63 may also be one of the lower respiratory pathogen in China.</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>

The research of saffold virus in children with lower respiratory tract infection in Changsha / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate prevalence of Saffold virus (SAFV) in Changsha area of hospitalized children with respiratory tract infection, and to discuss whether this virus is related to respiratory tract infection of children.</p><p><b>METHODS</b>643 nasopharyngeal aspirates samples were collected from hospitalized children with respiratory tract infection of the first affiliated hospital of Hunan nomal university during Nov. 2007 to Oct. 2008. Real-time fluorescent quanti-tative PCR(FQ-PCR) performed to screen the 5'UTR gene. And then analyze clinical data.</p><p><b>RESULTS</b>SAFV were detected in 67 patients (10.42%) out of the 643 children, it was not detected over 5 years of age. The virus were detected in 8 patients (25.81%) out of the 31 children with persistent pneumonia and chronic pneumonia, there was statistically significant.</p><p><b>CONCLUSION</b>There existed SAFV infection in hospitalized children with lower respiratory infection in Changsha area; SAFV maybe related to disease onset with lower respiratory tract infection of children.</p>

Detection and clinical characteristics analysis of human bocavirus 1-3 in children for acute respiratory infection in Lanzhou area / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the clinical and molecular epidemiology characteristics of human Bocavirus 1-3 (HBoV1-3) in children for acute respiratory infection in Lanzhou area.</p><p><b>METHODS</b>Nasopharyngeal aspiration samples and throat swabs were collected from 524 children with ARTI at the First Hospital of Lanzhou University, Gansu Province, China, between December 2009 and November 2010. Nested PCR was employed to screening HBoV1-3, which amplified a 518-bp fragment of the partial NS1 gene. Furthermore, a standard reverse transcription-PCR was used to screen for other common respiratory viruses.</p><p><b>RESULTS</b>The overall frequency of HBoV was 8.2% (43/524), lining up behind human rhinovirus, RSV, parainfluenza virus 3. Thirty of the HBoV-postive children(69.8%) were co-infected with other respiratory viruses. The prevalence of HBoV1 in ALRTI was obviously higher than that in AURI. The 2 HBoV2 NS1 sequences shared 99% and 100% nucleotide sequence identity with HBoV2 strain CU47TH respectively. Two cases of HBoV2 postive children appears gastrointestinal symptoms. The one HBoV3 NS1 sequences shared 99% nucleotide sequence identity with HBoV3 isolate 46-BJ07.</p><p><b>CONCLUSION</b>The HBoV3 was detected at the first time in lanzhou area. HBoV1-3 infection exists in children with acute respiratory tract infections in Lanzhou region, HBoV1 were dominant. The mixed infection rate was higher.</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>

Value of fluorescence quantitative PCR assay of bronchoalveolar lavage fluid samples in the diagnosis of Mycoplasma pneumoniae pneumonia in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the value of fluorescence quantitative polymerase chain reaction (FQ-PCR) for detecting Mycoplasma pneumoniae (MP)-DNA in bronchoalveolar lavage fluid (BALF) in the early diagnosis of Mycoplasma pneumoniae pneumonia (MPP).</p><p><b>METHODS</b>FQ-PCR was used to detect MP-DNA in BALF obtained by fiberoptic bronchoscopy from 61 children with MPP, and the sensitivity and the specificity of FQ-PCR were compared with the traditional serological test.</p><p><b>RESULTS</b>The sensitivity and the specificity of BALF FQ-PCR for detecting MP-DNA were 94% and 100% respectively. The accuracy of BALF FQ-PCR assay for detecting MP-DNA was higher than that of the serological test at the early stage of the disease (1-7 days) (P<0.01). In the children with refractory MPP, BALF FQ-PCR assay also showed higher accuracy for detecting MP-DNA than the serological test (P<0.01). The copies of MP-DNA in children with refractory MPP were significant higher than those in children with common MPP (P<0.05). The copies of MP-DNA were positively correlated with CRP values (r=0.845, P<0.01).</p><p><b>CONCLUSIONS</b>FQ-PCR assay of BALF for detecting MP-DNA in BALF is superior to the serological test. It is a reliable method for the early diagnosis of MPP, especially refractory MPP. The copies of MP-DNA can be used as an index for evaluation of the treatment outcome of refractory MPP.</p>