Chunyan Liu

Identification of viral agents associated with diarrhea in young children during a winter season in Beijing, China

Abstract Background Viral diarrhea remains a major cause of childhood morbidity and mortality worldwide. Although rotavirus was extensively studied in China, few comprehensive studies of all viral agents related to diarrhea in children have been conducted. Objectives Our study was performed to investigate the role of enteric viruses in acute diarrhea in our country and to evaluate methods that could be used in routine diagnostics. Study design One hundred stool samples were collected from children under 5 years of age seeking medical care for acute diarrhea during the winter season 2000/2001 in Beijing Childrens Hospital. All specimens were initially screened microscopically for leucocytes/red blood cells. Samples with negative results were analyzed for virus presence using commercial EIAs and/or in-house RT-PCRs. Results At least one viral agent was found in 67% of the specimens. The frequency of rotavirus, astrovirus, norovirus and enteric adenovirus was 59%, 8%, 6% and 2%, respectively. Dual infections were found in 9.0% (6/67) of the positive samples. The results from rotavirus and astrovirus EIAs were concordant with those of rotavirus and astrovirus RT-PCRs. Conclusions Enteric viruses play an important role in pediatric diarrhea during the winter season in China. A combination of microscopic examination of stool samples with specific EIA assays to detect virus antigen in stool specimens may be suitable for routine diagnostics.

Human rhinovirus C infections mirror those of human rhinovirus A in children with community-acquired pneumonia

Abstract Background Human rhinoviruses (HRVs) are among the most common causes of community-acquired pneumonia (CAP) in children. However, the differential roles of the three HRV species HRV-A, HRV-B, and HRV-C in pediatric CAP are not fully understood. Objective To determine the distribution of HRV species and their roles in children hospitalized with CAP in Beijing, China. Study design Nasopharyngeal aspirates were collected between April 2007 and March 2008 from 554 children with a primary diagnosis of CAP. HRVs in the clinical samples were detected by RT-PCR and by sequencing. Infections with other respiratory viruses were identified by PCR. Results HRVs were detected in 99 patients (17.87%). Among these patients, 51.52% tested positive for HRV-A, 38.38% for HRV-C, and 10.10% for HRV-B. HRVs were detected throughout the study period. The monthly distribution of HRV infections varied with HRV species. Median age, gender, symptoms, severity, and duration of hospitalization for single HRV-C infections were similar to those observed for single HRV-A infections. Co-infections with other respiratory viruses were detected in 57.58% of the HRV-positive children. HRV/RSV dual infections were correlated with a higher frequency of shortness of breath (HRV-A group, P 2tail =0.01; HRV-C group, P 2tail =0.015) and lower median ages (HRV-A group, P 2tail =0.049; HRV-C group, P 2tail =0.009). Conclusion Our study shows that HRV-C strains circulate at a prevalence intermediate between HRV-A and HRV-B. The severity of clinical manifestations for HRV-C is comparable to that for HRV-A in children with CAP. These findings point to an important role of both HRV-A and HRV-C in pediatric CAP.

WU and KI polyomavirus present in the respiratory tract of children, but not in immunocompetent adults

Abstract Background Recently, two new polyomaviruses (PyV), termed WUPyV and KIPyV, were identified in respiratory tract specimens from children with acute respiratory tract infections (ARTIs). However, their roles in the disease have not been determined. Objectives To determine the prevalence of WUPyV and KIPyV in the Chinese population suffering from ARTIs in Beijing, China, and to examine their possible role in causing disease. Study design Nasopharyngeal aspirates, nasal swabs and throat swabs were collected from 415 children and 297 immunocompetent adults with lower ARTIs (LARTIs). The specimens were screened by polymerase chain reaction for the presence of WUPyV, KIPyV, and other common respiratory pathogens. Results Although none of the adults sampled were positive for either virus, WUPyV in 10 (2.4%) children and KIPyV was detected in 2 (0.5%) of the children sampled, respectively. Eleven of the positive cases were co-detected with either rhinovirus (6/11), respiratory syncytial virus (4/11), parainfluenzavirus virus (3/11) or Mycoplasma pneumoniae (2/11). Phylogenetic analysis of the WUPyV and KIPyV isolates showed that the nucleotide sequences were homologous to those of previously reported strains. Conclusions The presence of WUPyV and KIPyV in samples from children but not from immunocompetent adults suffering from LARTIs suggests that these viruses primarily infect the young population. Co-detection of additional respiratory pathogens in most of the specimens containing either WUPyV or KIPyV suggests that these viruses do not cause disease independently.

Viral etiology and clinical profiles of children with severe acute respiratory infections in China.

Background No comprehensive analysis is available on the viral etiology and clinical characterization among children with severe acute respiratory infection (SARI) in China during 2009 H1N1 pandemic and post-pandemic period. Methods Cohort of 370 hospitalized children (1 to 72 months) with SARI from May 2008 to March 2010 was enrolled in this study. Nasopharyngeal aspirate (NPA) specimens were tested by a commercial assay for 18 respiratory viral targets. The viral distribution and its association with clinical character were statistically analyzed. Results Viral pathogen was detected in 350 (94.29%) of children with SARI. Overall, the most popular viruses were: enterovirus/rhinovirus (EV/RV) (54.05%), respiratory syncytial virus (RSV) (51.08%), human bocavirus (BoCA) (33.78%), human parainfluenzaviruse type 3 (PIV3) (15.41%), and adenovirus (ADV) (12.97%). Pandemic H1N1 was the dominant influenza virus (IFV) but was only detected in 20 (5.41%) of children. Moreover, detection rate of RSV and human metapneumovirus (hMPV) among suburb participants were significantly higher than that of urban area (P<0.05). Incidence of VSARI among suburb participants was also significant higher, especially among those of 24 to 59 months group (P<0.05). Conclusion Piconaviruses (EV/RV) and paramyxoviruses are the most popular viral pathogens among children with SARI in this study. RSV and hMPV significantly increase the risk of SARI, especially in children younger than 24 months. Higher incidence of VSARI and more susceptibilities to RSV and hMPV infections were found in suburban patients.

Human parainfluenza virus type 4 infection in Chinese children with lower respiratory tract infections: a comparison study.

Abstract Background Human parainfluenza viruses (HPIVs) are a leading cause of acute respiratory tract infections (ARTIs). Although HPIV-4 has been associated with mild ARTIs for years, recent investigations have also associated HPIV-4 infection with severe respiratory syndromes and with outbreaks of ARTIs in children. Objectives To characterize the role of HPIV-4 and its clinical features in children with acute lower respiratory tract infections (ALRTIs) in Beijing, China. Study design Nasopharyngeal aspirates were collected from 2009 hospitalized children with ALRTIs between March 2007 and April 2010. RT-PCR and PCR analyses were used to identify HPIV types and other known respiratory viruses. Results HPIVs were detected in 246 (12.2%) patients, of whom 25 (10.2%) were positive for HPIV-4, 11 (4.5%) for HPIV-2, 51 (20.7%) for HPIV-1, 151 (61.4%) for HPIV-3, and 8 (3.3%) were co-detected with different types of HPIVs. Like HPIV-3, HPIV-4 was detected in spring, summer, and late fall over the study period. Seasonal incidence varied for HPIV-1 and -2. The median patient age was 20 months for HPIV-4 infections and 7–11 months for HPIV-1, -2, and -3 infections, but the clinical manifestations did not differ significantly between HPIV-1, -2, -3, and -4 infections. Moreover, co-detection of HPIV-4 (44%) with other respiratory viruses was lower than that of HPIV-1 (62.7%), HPIV-2 (63.6%), and HPIV-3 (72.7%). Conclusions HPIV-4 plays an important role in Chinese paediatric ALRTIs. The epidemiological and clinical characteristics reported here improve our understanding of the pathogenesis associated with HPIV-4.

Human Parainfluenza Virus-Associated Respiratory Tract Infection among Children and Genetic Analysis of HPIV-3 Strains in Beijing, China

The relevance of human parainfluenza viruses (HPIVs) to the epidemiology of acute respiratory infections (ARI) in China is unclear. From May 2008 to September 2010, 443 nasopharyngeal aspirates (NPAs) from hospitalized pediatric patients (age from 1 to 93 months) in Beijing were collected and screened for HPIVs and other common respiratory viruses by real-time RT-PCR. Sixty-two of 443 samples were positive for HPIVs with 4 positive for HPIV-2 and 58 positive for HPIV-3, indicating that HPIV-3 was the predominant virus present during the study period. A phylogenetic tree based on all the available HN (hemagglutinin-neuraminidase) sequences of HPIV-3 indicated that three distinct clusters (A,B, and C) were circulating with some temporal and regional clustering. Cluster C was further divided into sub-clusters, C1, C2, C3 and C4. HPIV-3 from Beijing isolates belonged to sub-cluster C3, and were grouped with the isolates from two Provinces of China and the neighboring country of Japan. Genetic analysis based on entire HN gene revealed that the HPIV-3 isolates from Beijing were highly similar with 97.2%–100% identity at the nucleotide level and these could be divided into two closely related lineages, C3a and C3b. These findings suggested that there was co-circulation of multiple lineages of HPIV-3 in the Beijing region during the study period. This is the first study to describe the epidemiology and molecular characterization of HPIVs in China.

Saffold Cardioviruses of 3 Lineages in Children with Respiratory Tract Infections, Beijing, China

To clarify the potential for respiratory transmission of Saffold cardiovirus (SAFV) and characterize the pathogen, we analyzed respiratory specimens from 1,558 pediatric patients in Beijing. We detected SAFV in 7 (0.5%) patients and identified lineages 1–3. However, because 3 patients had co-infections, we could not definitively say SAFV caused disease.

Dynamic expression of viral and cellular microRNAs in infectious mononucleosis caused by primary Epstein-Barr virus infection in children

BackgroundEpstein-Barr virus (EBV) was the first virus identified to encode microRNAs (miRNAs). Both of viral and human cellular miRNAs are important in EBV infection. However, the dynamic expression profile of miRNAs during primary EBV infection was unknown. This study aimed to investigate the dynamic expression profile of viral and cellular miRNAs in infectious mononucleosis (IM) caused by primary EBV infection.MethodsThe levels of viral and cellular miRNAs were measured in fifteen pediatric IM patients at three different time-points. Fifteen healthy children who were seropositive for EBV were enrolled in the control group. Relative expression levels of miRNAs were detected by quantitative real-time PCR (qPCR) assay.ResultsEBV-miR-BHRF1-1, 1-2-3P, miR-BART13-1, 19-3p, 11-3P, 12–1, and 16–1 in IM patients of early phase were significantly higher than in healthy children. Most cellular miRNAs of B cells, such as hsa-miR-155-5p, −34a-5p, −18b-5p, −181a-5p, and −142-5p were up-regulated; while most of cellular miRNAs of CD8 + T cells, such as hsa-miR-223, −29c-3p, −181a, −200a-3p, miR-155-5p, −146a, and −142-5p were down-regulated in IM patients. With disease progression, nearly all of EBV-miRNAs decreased, especially miR-BHRF1, but at a slower rate than EBV DNA loads. Most of the cellular miRNAs of B cells, including hsa-miR-134-5p, −18b-5p, −34a-5p, and -196a-5p increased with time. However, most of the cellular miRNAs of CD8 + T cells, including hsa-let-7a-5p, −142-3p, −142-5p, and −155-5p decreased with time. Additionally, hsa-miR-155-5p of B cells and hsa-miR-18b-5p of CD8+ T cells exhibited a positive correlation with miR-BHRF1-2-5P and miR-BART2-5P (0.96 ≤ r ≤ 0.99, P < 0.05). Finally, hsa-miR-181a-5p of B cells had positive correlation with miR-BART4-3p, 4-5P, 16–1, and 22 (0.97 ≤ r ≤ 0.99, P < 0.05).ConclusionsOur study is the first to describe the expression profile of viral and cellular miRNAs in IM caused by primary EBV infection. These results might be the basis of investigating the pathogenic mechanism of EBV-related diseases and bring new insights into their diagnosis and treatment.

Bocavirus in Children with Respiratory Tract Infections

To the Editor: Four species of human bocavirus (HBoV1–4) have been identified since 2005 (1–4). Several reports have documented that HBoV1 are prevalent in respiratory tract samples. Although there may be many asymptomatic carriers, HBoV1 has been shown to cause respiratory tract diseases (1,5,6). HBoV2 has mainly been detected in fecal samples and has been linked to gastroenteritis (3,7,8). HBoV3 and HBoV4 have recently also been detected in fecal samples (3,4), although no link to disease has been established for these 2 species.

Human metapneumovirus associated with community-acquired pneumonia in children in Beijing, China†‡

Community‐acquired pneumonia is a major cause of morbidity and mortality in children worldwide. However, few studies have been conducted on the infection of human metapneumovirus (hMPV) associated with pediatric community‐acquired pneumonia in China. Nasopharyngeal aspirates were collected between July 2008 and June 2010 from 1,028 children, aged ≤16.5 years, who were diagnosed with community‐acquired pneumonia in Beijing, China. Reverse‐transcriptase polymerase chain reaction was used to screen the samples for hMPV and common respiratory viruses. hMPV was detected in 6.3% of the patients with community‐acquired pneumonia. This detection rate is the third highest for a respiratory virus in children with community‐acquired pneumonia, after that of rhinovirus (30.9%) and respiratory syncytial virus (30.7%). The detection rate of hMPV in 2008/2009 (42/540, 7.8%) was significantly higher than in 2009/2010 (23/488, 4.7%; χ2 = 4.065, P = 0.044). The hMPV subtypes A2, B1, and B2 were found to co‐circulate, with A2 being most prevalent. These results indicate that hMPV plays a substantial role in pediatric community‐acquired pneumonia in China. Overall, these findings provide a better understanding of the epidemiological and clinical features of hMPV infections. J. Med. Virol. 85:138–143, 2012.