Comparison of the clinical features of human bocavirus and metapneumovirus lower respiratory tract infections in hospitalized children in Suzhou, China.

Objective: We compared the clinical data of hospitalized children with lower respiratory tract infections caused by human bocavirus (HBoV) and human metapneumovirus (hMPV). Methods: In total, 8,430 children admitted to the Department of Respiration, Children's Hospital of Soochow University for lower respiratory tract infections from January 2017 to October 2021 were enrolled. Seven common respiratory viruses, including respiratory syncytial virus, influenza virus A, influenza virus B, parainfluenza virus (PIV) I, PIV II, PIV III, and adenovirus, were detected by direct immunofluorescence assay, whereas human rhinovirus and hMPV were detected by reverse transcription-polymerase chain reaction. Mycoplasma pneumoniae (MP) and HBoV were detected by real-time fluorescence quantitative polymerase chain reaction. Bacteria was detected in blood, nasopharyngeal secretion, bronchoalveolar lavage specimen or pleural fluid by culture. In parallel, MP was detected by enzyme-linked immunosorbent assay. In addition, we performed metagenomic testing of alveolar lavage fluid from some of the patients in our study. Results: The detection rate of HBoV was 6.62% (558/8430), whereas that of hMPV was 2.24% (189/ 8430). The detection rate of HBoV was significantly higher in children aged 1 to <3 years than in other age groups, but there were no significant differences in positivity rates for hMPV by age. Before 2020, the incidence of HBoV infection peaked in summer and autumn, whereas that of hMPV peaked in spring. The epidemiology of both HBoV and hMPV has changed because of the impact of the novel coronavirus. Among the positive cases, the HBoV mixed infection rate was 51.6%, which was similar to that for hMPV mixed infection (44.4%). Comparing clinical characteristics between HBoV and hMPV single infection, the median age of children was 17 months in the HBoV group and 11 months in the hMPV group. In the HBoV single infection group, 31 patients (11.5%) had pulse oxygen saturation of less than 92% on admission, 47 (17.4%) had shortness of breath, and 26 (9.6%) presented with dyspnea. Meanwhile, four patients (3.8%) in the hMPV single infection group had pulse oxygen saturation of less than 92% on admission, eight (7.6%) displayed shortness of breath, and three (2.9%) had dyspnea. The proportion of patients requiring mechanical ventilation and the rate of PICU admission were higher in the HBoV group than in the hMPV group. Conclusion: The prevalence of HBoV infection is higher than that of hMPV infection in children with lower respiratory tract infection in Suzhou, and HBoV is more likely to cause severe infection than hMPV. Public health interventions for COVID-19 outbreaks have affected the prevalence of HBoV and hMPV.

Comparison of the clinical features of human bocavirus and metapneumovirus lower respiratory tract infections in hospitalized children in Suzhou, China

Objective We compared the clinical data of hospitalized children with lower respiratory tract infections caused by human bocavirus (HBoV) and human metapneumovirus (hMPV). Methods In total, 8,430 children admitted to the Department of Respiration, Children's Hospital of Soochow University for lower respiratory tract infections from January 2017 to October 2021 were enrolled. Seven common respiratory viruses, including respiratory syncytial virus, influenza virus A, influenza virus B, parainfluenza virus (PIV) I, PIV II, PIV III, and adenovirus, were detected by direct immunofluorescence assay, whereas human rhinovirus and hMPV were detected by reverse transcription-polymerase chain reaction. Mycoplasma pneumoniae (MP) and HBoV were detected by real-time fluorescence quantitative polymerase chain reaction. Bacteria was detected in blood, nasopharyngeal secretion, bronchoalveolar lavage specimen or pleural fluid by culture. In parallel, MP was detected by enzyme-linked immunosorbent assay. In addition, we performed metagenomic testing of alveolar lavage fluid from some of the patients in our study. Results The detection rate of HBoV was 6.62% (558/8430), whereas that of hMPV was 2.24% (189/ 8430). The detection rate of HBoV was significantly higher in children aged 1 to <3 years than in other age groups, but there were no significant differences in positivity rates for hMPV by age. Before 2020, the incidence of HBoV infection peaked in summer and autumn, whereas that of hMPV peaked in spring. The epidemiology of both HBoV and hMPV has changed because of the impact of the novel coronavirus. Among the positive cases, the HBoV mixed infection rate was 51.6%, which was similar to that for hMPV mixed infection (44.4%). Comparing clinical characteristics between HBoV and hMPV single infection, the median age of children was 17 months in the HBoV group and 11 months in the hMPV group. In the HBoV single infection group, 31 patients (11.5%) had pulse oxygen saturation of less than 92% on admission, 47 (17.4%) had shortness of breath, and 26 (9.6%) presented with dyspnea. Meanwhile, four patients (3.8%) in the hMPV single infection group had pulse oxygen saturation of less than 92% on admission, eight (7.6%) displayed shortness of breath, and three (2.9%) had dyspnea. The proportion of patients requiring mechanical ventilation and the rate of PICU admission were higher in the HBoV group than in the hMPV group. Conclusion The prevalence of HBoV infection is higher than that of hMPV infection in children with lower respiratory tract infection in Suzhou, and HBoV is more likely to cause severe infection than hMPV. Public health interventions for COVID-19 outbreaks have affected the prevalence of HBoV and hMPV.

Clinical characteristics and etiology of children with bronchiolitis before and during the COVID-19 pandemic in Suzhou, China

Objective We sought to compare the clinical characteristics and etiology of children with bronchiolitis in Suzhou before the pandemic of coronavirus disease 2019 (COVID-19) with those during the pandemic. Methods Children who were hospitalized with bronchiolitis in the Department of Respiratory Disease, Children's Hospital of Soochow University were retrospectively enrolled over 3 consecutive years (2019, 2020, and 2021) from February 1 to January 31. Medical records were reviewed for etiology, clinical manifestations, and laboratory examination results. Results The pathogen detection rate and the positive respiratory syncytial virus (RSV) detection rate were lowest in 2020 and highest in 2021. The rate of human rhinovirus detection in 2021 was higher than that in 2019 but similar to that in 2020. The RSV-positive rate differences among the 3 years varied by age group. Regarding the monthly distribution of RSV-positive cases over the 3-year study, all age groups showed a significant increase in the number of cases during the winter of 2021, and this increase started as early as October. With regard to clinical manifestations, the proportion of children presenting with stuffy nose rhinorrhea in 2021 [73.33% (165/225)] was greater than that in 2019 [48.61% (122/251)] and 2020 [57.06% (97/170)], while the proportion of children with gastrointestinal symptoms in 2021 [11.56% (26/225)] was smaller than that in 2019 [25.50% (64/251)] but similar to that in 2020 [17.06% (29/170)]. Conclusions After the implementation of COVID-19 pandemic-related interventions, significantly lower pathogen detection and RSV-positive rates were observed in children with bronchiolitis in 2020. An upward trend in these rates was observed in 2021, coinciding with the relaxation of COVID-19 prevention measures. Strengthening infection control and surveillance systems is extremely important for future work.

Clinical Characteristics of Pediatric Respiratory Tract Infection and Respiratory Pathogen Isolation During the Coronavirus Disease 2019 Pandemic.

Objective: We sought to compare the clinical characteristics of pediatric respiratory tract infection and respiratory pathogen isolations during the coronavirus disease (COVID-19) pandemic to those of cases in 2018 and 2019. Methods: Our study included all children from 28 days to 15 years old with respiratory tract infections who were admitted to the Department of Respiration, in the Children's Hospital of Soochow University, between January 2018 and December 2020. Human rhinovirus (HRV) and human metapneumovirus (hMPV) were detected by reverse transcription polymerase chain reaction (RT-PCR). Mycoplasma pneumoniae (MP) and human bocavirus (HBoV) were detected by real-time fluorescence quantitative polymerase chain reaction (qPCR); In parallel, Mycoplasma pneumoniae was detected by enzyme-linked immunosorbent assays, and bacteria were detected by culture in blood, bronchoalveolar lavage specimen, and pleural fluid. Results: Compared to 2018 and 2019, the pathogen detection rate was significantly lower in 2020. With regard to infections caused by single pathogens, in 2020, the detection rates of MP were the lowest and those of HRV were the highest when compared to those in 2018 and 2019. Meanwhile, the positive rates of respiratory syncytial virus (RSV) and hMPV reported in 2020 were less than those recorded in 2018 but similar to those recorded in 2019. Also, the 2020 rate of adenovirus (ADV) was lower than that recorded in 2019, but similar to that recorded in 2018. There were no statistical differences in the positive rates of HBoV and PIV III over the 3 years surveyed. Infections in infants were significantly less common in 2020, but no significant difference was found among children aged 1 to 3 years. The detection rate of pathogens in children old than 5 years in 2020 was significantly lower than those recorded in the previous 2 years. Notably, the pathogen detection rates in the first and second quarters of 2020 were similar to those recorded in the previous 2 years; however, the rates were reduced in the third and fourth quarters of 2020. As for co-infections, the positive rate was at its lowest in 2020. In the previous 2 years, viral-MP was the most common type of mixed infection. By contrast, in 2020, viral-viral infections were the most common combination. Conclusion: The pathogen detection rate was significantly reduced in Suzhou City during the COVID-19 pandemic. Public interventions may help to prevent respiratory pathogen infections in children.

Glycosylation of viral proteins: Implication in virus-host interaction and virulence.

Glycans are among the most important cell molecular components. However, given their structural diversity, their functions have not been fully explored. Glycosylation is a vital post-translational modification for various proteins. Many bacteria and viruses rely on N-linked and O-linked glycosylation to perform critical biological functions. The diverse functions of glycosylation on viral proteins during viral infections, including Dengue, Zika, influenza, and human immunodeficiency viruses as well as coronaviruses have been reported. N-linked glycosylation is the most common form of protein modification, and it modulates folding, transportation and receptor binding. Compared to N-linked glycosylation, the functions of O-linked viral protein glycosylation have not been comprehensively evaluated. In this review, we summarize findings on viral protein glycosylation, with particular attention to studies on N-linked glycosylation in viral life cycles. This review informs the development of virus-specific vaccines or inhibitors.