Human Bocavirus Research Articles

Unexpected Severe Bocavirus Infections among Hospitalized Children during the COVID-19 Pandemic

Abstract Objective Acute respiratory tract infections are one of the leading causes of morbidity and mortality in children. Although human bocavirus (HBoV) infections are not as common as other seasonal respiratory viruses, children who are infected with HBoV are more likely to suffer from a variety of respiratory conditions, including the common cold, acute otitis media, asthma exacerbations, bronchiolitis pneumonia, some of the affected children require pediatric intensive care unit stay. Here, we aimed to evaluate pediatric bocavirus (HBoV) cases presenting with severe respiratory tract symptoms during the coronavirus disease 2019 (COVID-19) pandemic. Methods This retrospective study evaluated the medical records of children diagnosed with respiratory infections, followed up at the Faculty of Medicine, Eskisehir Osmangazi University between September 2021 and March 2022. In this study, patients with HBoV identified using nasopharyngeal polymerase chain reaction (PCR) were considered positive. Cases were analyzed retrospectively for their clinical characteristics. Results This study included 54 children (29 girls and 25 boys) with HBoV in nasopharyngeal PCR samples. The cases ranged in age from 1 month to 72 months (median 25 months). At the time of presentation, cough, fever, and respiratory distress were the most prevalent symptoms. Hyperinflation (48%), pneumonic consolidation (42%), and pneumothorax–pneumomediastinum (7%) were observed on the chest X-ray; 54% of the children required intensive care unit stay. The median length of hospitalization was 6 days. Bacterial coinfection was detected in 7 (17%) children, while HBoV and other viruses were present in 20 (37%) children; 57% of children received supplemental oxygen by mask, 24% high-flow nasal oxygen, 7% continuous positive airway pressure, and 9% invasive mechanical ventilation support. Antibiotics were given to 34 (63%) cases, and systemic steroid treatment was given to 41 (76%) cases. Chest tubes were inserted in three out of the four cases with pneumothorax–pneumomediastinum. All patients were recovered and were discharged from the hospital. Conclusion The COVID-19 pandemic changed the epidemiology of seasonal respiratory viruses and the clinical course of the diseases. Although it usually causes mild symptoms, severe respiratory symptoms can lead to life-threatening illnesses requiring intensive care admission.

Comparison of common human respiratory pathogens among hospitalized children aged ≤ 6 years in Hainan Island, China, during spring and early summer in 2019-2021.

The coronavirus disease 2019 (COVID-19) pandemic and related public health intervention measures have been reported to have resulted in the reduction of infections caused by influenza viruses and other common respiratory viruses. However, the influence may be varied in areas that have different ecological, economic, and social conditions. This study investigated the changing epidemiology of 8 common respiratory pathogens, including Influenza A (IFVA), Influenza B (IFVB), Respiratory syncytial virus (HRSV), rhinovirus (RV), Human metapneumovirusAdenovirus, Human bocavirus, and Mycoplasma pneumoniae, among hospitalized children during spring and early summer in 2019-2021 in two hospitals in Hainan Island, China, in the COVID-19 pandemic era. The results revealed a significant reduction in the prevalence of IFVA and IFVB in 2020 and 2021 than in 2019, whereas the prevalence of HRSV increased, and it became the dominant viral pathogen in 2021. RV was one of the leading pathogens in the 3 year period, where no significant difference was observed. Phylogenetic analysis revealed close relationships among the circulating respiratory viruses. Large scale studies are needed to study the changing epidemiology of seasonal respiratory viruses to inform responses to future respiratory virus pandemics.

The disappearance of respiratory syncytial virus and influenza viruses in children during the second year of the COVID-19 pandemic - are non-pharmaceutical interventions as effective as vaccines?

Respiratory viral diseases are common in children. A viral diagnostic test is necessary, because COVID-19 shows signs and symptoms similar to those of common respiratory viruses. The article aims at analyzing the presence of respiratory viruses that were common before the pandemic in children who were tested for suspected COVID-19, and is also concerned with how common respiratory viruses were impacted by COVID-19 measures during the second year of pandemic. Nasopharyngeal swabs were examined to detect the presence of respiratory viruses. The respiratory panel kit included SARS-CoV-2, influenza A and B, rhinovirus/enterovirus, parainfluenza 1, 2, 3 and 4, coronaviruses NL 63, 229E, OC43, and HKU1, human metapneumovirus A/B, human bocavirus, respiratory syncytial virus (RSV) A/B, human parechovirus, and adenovirus. Virus scans were compared during and after the restricted period. No virus was isolated from the 86 patients. SARS-CoV-2 was the most frequently observed virus, as expected, and rhinovirus was the second, and coronavirus OC43 was the third. Influenza viruses and RSV were not detected in the scans. Influenza and RSV viruses disappeared during the pandemic period and rhinovirus was the second most common virus after the CoVs during and after the restriction period. Non-pharmaceutical interventions should be established as a precaution to prevent infectious diseases even after the pandemic.

Controversies and knowledge expansion in psychiatry

Respiratory viruses infection is a worldwide human concern annually. The main viral respiratory diseases are caused by a variety of viruses sharing similar threats and affecting the respiratory system. Among all, influenza viruses, respiratory syncytial virus, parainfluenza viruses, respiratory adenoviruses, rhinoviruses, human bocaviruses, human metapneumovirus and coronaviruses are the main common respiratory viruses affecting human population. The recent coronavirus disease 19 pandemic has revealed critical knowledge gaps required to update in the transmission and pathological induced pathways for respiratory viruses. To date, several evidences suggest that human viruses can hijack extracellular vesicles (EVs) to deliver proteins, mRNAs, microRNAs and whole viral particles during viral life cycle in the host. Thus, several investigations have reported that also respiratory viruses use EVs to deliver viral nucleic acid and proteins, even including the potentiality of carrying whole viral particle. This evidence demonstrates the ability of the EVs produced in infected cells to deliver respiratory viral components to uninfected cells, positively or negatively counteracting new viral infection. Additionally, EVs derived from biological fluids of clinical samples may increase the risk to induce severe respiratory viruses-associated diseases in site far from the respiratory tract and for prolonged time. Here, it has been reviewed the advantages of the respiratory viruses EVs interaction regarding their ability to enhance viral infection, to evade antiviral response, to regulate virus-immune response and to mediate diseases. All these data confirm a potential role of the association between EVs and respiratory viruses infection. This suggests that further studies to define the implication of this interaction in viral life cycle in human population are needed.

Prevalence of SARS-COV-2 and other respiratory pathogens among a Jordanian subpopulation during Delta-to-Omicron transition: Winter 2021/2022.

Acute respiratory tract infections (ARTIs) during the winter months are associated with higher morbidity and mortality compared to other seasons of the year, with children below five, elderly, and immunocompromised patients being the most susceptible. Influenza A and B viruses, rhinovirus, coronaviruses, respiratory syncytial virus, adenovirus, and parainfluenza viruses, are the most frequently identified causes of viral ARTIs. In addition, the emergence of SARS-CoV-2 in 2019 provided an additional viral cause of ARTIs. The aim of this study was to provide an overview of the epidemiological status of upper respiratory infections, their main causative agents, and reported clinical presentation in the winter months of 2021, during two important surges of COVID-19 in Jordan. Nasopharyngeal samples were collected from 339 symptomatic patients during the period from December 2021 to March 2022, followed by nucleic acid isolation using a Viral RNA/DNA extraction Kit. The causative virus species associated with the patient's respiratory symptoms was determined utilizing a multiplex real-time PCR targeting 21 viruses, 11 bacteria, and a single fungus. SARS-CoV-2 was identified in 39.2% of the patients (n = 133/339). A total of 15 different pathogens were also identified as co-infections among these 133 patients (n = 67/133). SARS-CoV-2-Bacterial coinfections (37.6%, n = 50/133) were the most frequent, with Bordetella species being the most common, followed by Staphylococcus aureus, and H.influenzae type B. Viral coinfection rate was 27.8% (n = 37/133), with Influenza B virus and Human bocavirus being the most common. In Conclusion, Both SARS-CoV-2, influenza B virus, and Bordetella accounted for the majority of infections in patients with URTI during the winter months of 2021-2022. Interestingly, more than 50% of the patients with symptoms of URTIs were confirmed to have a coinfection with two or more respiratory pathogens, with SARS-CoV-2 and Bordetella coinfection being most predominant.

Immediate and long-term changes in the epidemiology, infection spectrum, and clinical characteristics of viral and bacterial respiratory infections in Western China after the COVID-19 outbreak: a modeling study.

The impact of COVID-19 on the epidemiology, clinical characteristics, and infection spectrum of viral and bacterial respiratory infections in Western China is unknown. We conducted an interrupted time series analysis based on surveillance of acute respiratory infections (ARI) in Western China to supplement the available data. The positive rates of influenza virus, Streptococcus pneumoniae, and viral and bacterial coinfections decreased, but parainfluenza virus, respiratory syncytial virus, human adenovirus, human rhinovirus, human bocavirus, non-typeable Haemophilus influenzae, Mycoplasma pneumoniae, and Chlamydia pneumoniae infections increased after the onset of the COVID-19 epidemic. The positive rate for viral infection in outpatients and children aged <5 years increased, but the positive rates of bacterial infection and viral and bacterial coinfections decreased, and the proportion patients with clinical symptoms of ARI decreased after the onset of the COVID-19 epidemic. Non-pharmacological interventions reduced the positive rates of viral and bacterial infections in the short term but did not have a long-term limiting effect. Moreover, the proportion of ARI patients with severe clinical symptoms (dyspnea and pleural effusion) increased in the short term after COVID-19, but in the long-term, it decreased. The epidemiology, clinical characteristics, and infection spectrum of viral and bacterial infections in Western China have changed, and children will be a high-risk group for ARI after the COVID-19 epidemic. In addition, the reluctance of ARI patients with mild clinical symptoms to seek medical care after COVID-19 should be considered. In the post-COVID-19 era, we need to strengthen the surveillance of respiratory pathogens.

Viral detection from negative mumps cases with respiratory symptoms in Gwangju, South Korea in 2021.

Mumps is the second-most reported infectious disease in South Korea; however, due to the low pathogen confirmation rate in laboratory diagnoses, we proposed a method for reevaluating the high incidence rate via the laboratory verification of other viral diseases. In 2021, 63 cases of pharyngeal or cheek mucosal swabs of suspected mumps cases in Gwangju, South Korea, were assessed for causative pathogens using massive simultaneous pathogen testing. More than one respiratory virus was detected in 60 cases (95.2%), 44 (73.3%) of which were co-detected. Human rhinovirus was detected in 47 cases, followed by human herpesvirus (HHV)6 in 30; HHV4 (17), human bocavirus (17), HHV5 (10), and human parainfluenza virus 3 (6) were also detected. Our findings suggest the need for further investigations on the pathogenesis of diseases mimicking mumps, which are considered to aid with appropriate public health responses, treatment, and the prevention of infectious disease outbreaks. This article is protected by copyright. All rights reserved.

Epidemiology of respiratory syncytial virus in hospitalized children with community-acquired pneumonia in Guangzhou: a 10-year study.

Respiratory syncytial virus (RSV) is one of the most common virus causing community-acquired pneumonia (CAP) in children. To guide the prevention, diagnosis and treatment of RSV, we aimed to analyze the epidemiology of RSV in hospitalized children with CAP. A total of 9,837 hospitalized children (≤14 years old) with CAP from January 2010 to December 2019 were reviewed. Using the real-time polymerase chain reaction (RT-PCR), the oropharyngeal swab specimens were collected and tested for RSV, influenza virus A (INFA), influenza virus B (INFB), parainfluenza virus (PIV), enterovirus (EV), coronavirus (CoV), human metapneumovirus (HMPV), human bocavirus (HBoV), human rhinovirus (HRV), and adenovirus (ADV) for each patient. The detection rate of RSV was 15.3% (1,507/9,837). From 2010 to 2019, the RSV detection rate showed a wavy change (χ2=166.982, P<0.001), with the highest detection rate in 2011 (158/636, 24.8%). RSV can be detected throughout the year, with the highest detection rate in February (123/482, 25.5%). Children younger than 0.5 years old had the highest detection rate (410/1,671, 24.5%). The detection rate of RSV in male children (1,024/6,226, 16.4%) was higher than that in female children (483/3,611, 13.4%) (P<0.001). A proportion of 17.7% (266/1,507) of RSV positive cases were also co-infected with other viruses, and INFA (41/266, 15.4%) was the most common coinfection virus. After adjusting for potential confounders, the RSV-positive children were associated with increased risk of severe pneumonia [odds ratio (OR) 1.26, 95% confidence interval (CI): 1.04 to 1.53, P=0.019]. Moreover, children with severe pneumonia had significantly lower cycle threshold (CT) values of RSV than those without severe pneumonia (28.88±3.89 vs. 30.42±3.33, P<0.01). Patients with coinfection (38/266, 14.3%) had a higher risk of severe pneumonia than those without coinfection (142/1,241, 11.4%), but the difference was not statistically significant (OR 1.39, 95% CI: 0.94 to 2.05, P=0.101). The detection rate of RSV in CAP hospitalized children changed by years, months, ages, and sexes. CAP hospitalized children with RSV are more likely to develop severe pneumonia than those without RSV. Policy makers and doctors should make timely adjustments to prevention measures, medical resources and treatment options based on these epidemiological characteristics.

A Review on Human Metapneumovirus and Human Bocavirus Associated with Acute Respiratory Tract Infections

One of the significant causes of morbidity and mortality among young children in developing nations is acute respiratory tract infections (ARTIs). It is also highly contagious, widely prevalent, and transmissible from person to person. It risks young children, the elderly, and those with immune system disorders. Acute respiratory infections are thought to cause 2.6 million child deaths annually worldwide, according to the World Health Organization (WHO) [1]. Infections in children with human metapneumovirus (hMPV) and bocavirus (HBoV) are linked to a high prevalence of ARTIs. It has been determined that hMPV is the second-leading cause of infant bronchiolitis, after the respiratory syncytial virus (RSV), of upper and lower respiratory tract infections. Although HBoV was first discovered in children's airways, the high detection rates of other viral pathogens and the discovery of HBoV in stool raise doubts about the virus's significance in respiratory tract infections. According to the published literature, only a few studies have identified ARTIs or demonstrated the importance of early diagnosis and treatment of ARTIs. This review article aims to thoroughly explain the aetiology, epidemiology, clinical characteristics, diagnostic approaches, and management of hMPV and HBoV.

Case-control study of relationship of infection by respiratory viruses with acute otitis media in Chinese children

BackgroundAcute otitis media (AOM) may occur as a complication of viral upper respiratory infection (URI) in children. Our objective was to examine children with URI + AOM or URI alone to determine the association of infection by different common respiratory viruses with AOM. MethodsNasopharyngeal swabs were collected from March 2014 to February 2015. Quantitative PCR was then used to identify the following 10 common respiratory viruses: respiratory syncytial virus (RSV); parainfluenza viruses 1–4 (PIVs); influenza virus type A (IFVA); influenza virus type B; human rhinovirus (HRV); enterovirus; human metapneumovirus; human coronavirus OC43, 229E, NL63, and HKU1; adenovirus; and human bocavirus. ResultsWe examined 255 children with URIs (mean age: 32.9 ± 18.7 months), and 164 (64.1%) of them tested positive for at least one respiratory virus. The most common viruses were RSV (44, 24.3%), PIVs (28, 15.5%), and IFVA (25, 13.8%). Positivity for RSV was significantly greater in the URI + AOM group than in the URI group, but these groups did not differ in infection rates for the other 9 viruses. There were also significant seasonal differences in positivity for RSV, IFVA, HRV,HBoV, PIVs and EV. ConclusionOur results indicated a relationship between infection by common respiratory viruses and AOM in children from Beijing. A URI with RSV significantly increased the risk of AOM in these children.

Epidemiology and diagnosis of viral and bacterial central nervous system infections in Sri Lanka: A Narrative review

Bacterial central nervous system (CNS) infections are life-threatening diseases with high mortality and long-term neurological sequels, while viral CNS infections are mild and self-limited. In Sri Lanka, 1000-1500 and 150-250 patients with meningitis and encephalitis respectively are reported annually to the Epidemiology Unit. Haemophilus influenzae, Group B Streptococcus, Streptococcus pneumoniae, Escherichia coli, Mycobacterium tuberculosis, Neisseria meningitidis, Group D Streptococcus, Leptospira borgpetersenii serovar Tarasssovi, Listeria monocytogenes, Streptococcus bovis biotype 2, enterovirus, Herpes Simplex Virus type 1 and type 2, Varicella zoster virus and cytomegalovirus have been reported up to 2022 in patients with meningitis while dengue virus, Japanese encephalitis virus, Varicella zoster virus, West Nile virus, Human Bocavirus Type 1, 2 and 3, human adenovirus type 41, Echovirus type 9 and 25, Herpes Simplex Virus type 1 and Mycoplasma pneumoniae have been reported in patients with encephalitis and meningoencephalitis. However less than 10% of cases have a definitive aetiological diagnosis with conventional bacterial culture methods routinely used to diagnose bacterial CNS infections, while molecular assays are used only for selected common viral pathogens in government hospitals in Sri Lanka. Use of antibiotics prior to cerebrospinal fluid collection, delay in sample collection, and low volume of samples have been identified as factors for low sensitivity of test results. Scientists, microbiologists and virologists are responsible for developing new test methods to identify current and previously unidentified causative microorganisms to extend the spectrum of neurotropic organisms in Sri Lanka to enhance the aetiological diagnosis.

Comparison of MT-PCR with Quantitative PCR for Human Bocavirus in Respiratory Samples with Multiple Respiratory Viruses Detection

Human bocavirus (HBoV) is an important respiratory pathogen, especially in children, but it is often found in co-detection with other respiratory viruses, which makes the diagnostic approach challenging. We compared multiplex PCR and quantitative PCR for HBoV with multiplex tandem PCR (MT-PCR) in 55 cases of co-detection of HBoV and other respiratory viruses. In addition, we investigated whether there is a connection between the severity of the disease, measured by the localization of the infection, and amount of virus detected in the respiratory secretions. No statistically significant difference was found, but children with large amount of HBoV and other respiratory virus had a longer stay in hospital.

Human bocavirus 1 and 2 genotype-specific antibodies for rapid antigen testing in pediatric patients with acute respiratory infections.

Previous serological studies of human bocavirus (HBoV) 1 could not exclude cross-reactivity with the other three HBoVs, particularly HBoV2. To search for genotype-specific antibodies against HBoV1 and HBoV2, the divergent regions (DRs) located on the major capsid protein VP3 were defined through viral amino acid alignment and structure prediction. DR-deduced peptides were used as antigens to harvest corresponding anti-DR rabbit sera. To determine their genotype specificities for HBoV1 and HBoV2, these sera samples were used as antibodies against the antigens VP3 of HBoV1 and HBoV2 (expressed in Escherichia coli) in western blotting (WB), enzyme-linked immunosorbent assay (ELISA), and bio-layer interferometry (BLI) assays. Subsequently, the antibodies were evaluated with clinical specimens from pediatric patients with acute respiratory tract infection by indirect immunofluorescence assay (IFA). There were four DRs (DR1-4) located on VP3 with different secondary and tertiary structures between HBoV1 and HBoV2. Regarding the reactivity with VP3 of HBoV1 or HBoV2 in WB and ELISA, high intra-genotype cross-reactivity of anti-HBoV1 or HBoV2 DR1, DR3, and DR4, but not anti-DR2, was observed. Genotype-specific binding capacity of anti-DR2 sera was confirmed by BLI and IFA, in which only anti-HBoV1 DR2 antibody reacted with HBoV1-positive respiratory specimens. Antibodies against DR2, located on VP3 of HBoV1 or HBoV2, were genotype specific for HBoV1 and HBoV2, respectively.

Applicability of crAssphage as a performance indicator for viral reduction during activated sludge wastewater treatment

A major threat to water quality is the discharge of human-derived wastewater, which can cause waterborne illnesses associated with enteric viruses. A poor association exists between fecal indicator bacteria and virus fate in the environment, especially during wastewater treatment. In the current study, the potential of using a novel human gut bacteriophage crAssphage as a wastewater treatment process indicator was evaluated. Using qPCR, influent and effluent wastewater samples of two wastewater treatment plants were analyzed for crAssphage and human viruses including human bocavirus (HBoV), human adenovirus (HAdV), and human polyomavirus (HPyV). All samples were positive for crAssphage. The annual crAssphage concentrations varied between 1.45E + 04 and 2.39E + 08 gc/l in influent samples and from 1.25E + 04 to 7.88E + 06 gc/l in effluent samples. Human viruses concentrations were some orders of magnitude lower than that of crAssphage. Data demonstrated a significant correlation between crAssphage, HAdV, and HPyV during the wastewater treatment process, suggesting that crAssphage and human viral pathogens have similar removal mechanisms. Ultimately, this work concludes that crAssphage could be a performance indicator for viral reduction in the wastewater treatment process.

Human bocavirus 1 epidemiology in children in relation to virus load and codetection.

Human bocavirus 1 (HBoV1) has been associated with respiratory tract infections in children. We aimed at retrospectively describing patient characteristics, seasonality, pre-existing medical conditions, codetections, clinical manifestations and complications of HBoV1 infection in relation to viral load in the child population in Stockholm, with the overarching aim of elucidating the clinical significance of HBoV1. We included all hospitalised children 0-17 years testing positive for HBoV1 by real-time polymerase chain reaction on nasopharyngeal aspirates 1 July 2008-30 June 2019. Patients with HBoV1 single detection, high viral load expressed as an HBoV1-DNA cycle threshold (Ct) < 25, or both, were separately analysed. We retrieved information on pre-existing conditions and clinical course from the medical records. We found 768 episodes in 727 children, 496 (64.6%) male and 441 (60.7%) previously healthy. The median age was 17.6 months. Most (476/768, 62.0%) episodes occurred during December-March. HBoV1 was in 549 episodes (71.5%) codetected with other viruses. Ct < 25 was independently associated with young age, single detection of HBoV1 and presentation early in the epidemic season. We saw few differences in clinical manifestations between the subgroups. Our findings are consistent with primary HBoV1 infection causing mild-to-severe respiratory tract manifestations in young children.

Development of RPA-Cas12a-fluorescence assay for rapid and reliable detection of human bocavirus 1.

Human bocavirus (HBoV) 1 is considered an important pathogen that mainly affects infants aged 6-24 months, but preventing viral transmission in resource-limited regions through rapid and affordable on-site diagnosis of individuals with early infection of HBoV1 remains somewhat challenging. Herein, we present a novel faster, lower cost, reliable method for the detection of HBoV1, which integrates a recombinase polymerase amplification (RPA) assay with the CRISPR/Cas12a system, designated the RPA-Cas12a-fluorescence assay. The RPA-Cas12a-fluorescence system can specifically detect target gene levels as low as 0.5 copies of HBoV1 plasmid DNA per microliter within 40 min at 37°C without the need for sophisticated instruments. The method also demonstrates excellent specificity without cross-reactivity to non-target pathogens. Furthermore, the method was appraised using 28 clinical samples, and displayed high accuracy with positive and negative predictive agreement of 90.9% and 100%, respectively. Therefore, our proposed rapid and sensitive HBoV1 detection method, the RPA-Cas12a-fluorescence assay, shows promising potential for early on-site diagnosis of HBoV1 infection in the fields of public health and health care. The established RPA-Cas12a-fluorescence assay is rapid and reliable method for human bocavirus 1 detection. The RPA-Cas12a-fluorescence assay can be completed within 40 min with robust specificity and sensitivity of 0.5 copies/μl.

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

We compared the clinical data of hospitalized children with lower respiratory tract infections caused by human bocavirus (HBoV) and human metapneumovirus (hMPV). 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. 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. 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.

Highly Sensitive Multiplex Detection of Molecular Biomarkers Using Hybridization Chain Reaction in an Encoded Particle Microfluidic Platform

In the continuous combat against diseases, there is the need for tools that enable an improved diagnostic efficiency towards higher information density combined with reduced time-to-result and cost. Here, a novel fully integrated microfluidic platform, the Evalution™, is evaluated as a potential solution to this need. Encoded microparticles combined with channel-based microfluidics allow a fast, sensitive and simultaneous detection of several disease-related biomarkers. Since the binary code is represented by physically present holes, 210 different codes can be created that will not be altered by light or chemically induced degradation. Exploiting the unique features of this multiplex platform, hybridization chain reaction (HCR) is explored as a generic approach to reach the desired sensitivity. Compared to a non-amplified reference system, the sensitivity was drastically improved by a factor of 104, down to low fM LOD values. Depending on the HCR duration, the assay can be tuned for sensitivity or total assay time, as desired. The huge potential of this strategy was further demonstrated by the successful detection of a multiplex panel of six different nucleic acid targets including viruses and bacteria. The ability to not only discriminate these two categories but, with the same effort, also virus strains (human adenovirus and human bocavirus), virus subtypes (human adenovirus type B and D) and antibiotic-resistant bacteria (Streptococcus pneumonia), exemplifies the specificity of the developed approach. The effective, yet highly simplified, isothermal and protein-enzyme-free signal amplification tool reaches an LOD ranging from as low as 33 ± 4 to 151 ± 12 fM for the different targets. Moreover, direct detection in a clinically relevant sample matrix was verified, resulting in a detection limit of 309 ± 80 fM, approximating the low fM levels detectable with the gold standard analysis method, PCR, without the drawbacks related to protein enzymes, thermal cycling and elaborate sample preparation steps. The reported strategy can be directly transferred as a generic approach for the sensitive and specific detection of various target molecules in multiplex. In combination with the high-throughput capacity and reduced reagent consumption, the Evalution™ demonstrates immense potential in the next generation of diagnostic tools towards more personalized medicine.

Epidemiology and Acute Respiratory Distress Syndrome Propensity of Viral Respiratory Infections in Pediatric Intensive Care Units Prior to the Coronavirus Disease 2019 Pandemic

Abstract Objective This study aimed to determine the epidemiology and acute respiratory distress syndrome (ARDS) propensity of common respiratory viruses in a tertiary pediatric intensive care unit (PICU) among hospitalized children who were tested for respiratory viruses by polymerase chain reaction (PCR) prior to the coronavirus disease 2019 (COVID-19) pandemic. Methods Respiratory tract samples were collected from patients who were followed up in the Dokuz Eylul University Hospital pediatric intensive care unit between March 2015 and March 2020 and tested for viral pathogens. The results of 269 patients between 1 month and 18 years of age were evaluated retrospectively. Results In the 5 years preceding the COVID-19 pandemic, 269 patients with a lower respiratory infection were admitted to the PICU. A positive viral PCR result was detected in 160 patients (59.5%). Human rhinovirus was the most common virus (40%), followed by respiratory syncytial virus (26.3%), human bocavirus (10%), and seasonal coronaviruses (10%). Five (33.3%) of the fifteen children who developed ARDS were infected with influenza A/B, while four (26.7%) were infected with human metapneumovirus (hMPV). Conclusion Although rhinovirus was the most common viral agent in critically ill children, the incidence of ARDS was higher in children aged over 1 year who had influenza or hMPV infection.

Role of Polymerase Chain Reaction-Based Diagnosis of Respiratory Viruses in Febrile Neutropenic Patients.

Background Neutropenic patients are commonly affected by respiratory infections, whereas respiratory viral infections causing high morbidity and mortality are routinely diagnosed in developing countries like India. Our study aimed to investigate the prevalence of respiratory viral infections in pediatric cancer patients with febrile neutropenia. Methods This prospective study was performed on 45 neutropenia patients with hematological malignancies. Nasal swabs were collected and analyzed by real-time multiplex polymerase chain reaction (PCR), covering the following viruses: influenza A virus, influenza B virus, human parainfluenza virus (subtypes 1-4), human respiratory syncytial virus A and B, enterovirus, human-coronavirus (HCoV: HKU1, NL63, 229E, and OC43), human bocavirus, adenovirus, human rhinovirus, human-metapneumovirus A and B, human paraechovirus, and a bacteriumMycoplasma pneumoniae. Patients enrolled in the study since the COVID-19 pandemic was also detected for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results Of the 45 cases included in our study, 26 cases showed the presence of at least one positivity by PCR (57.7%): 23 patients had monoinfection with only one virus, two patients were found positive for coinfection with two viruses, and one patient was found positive for three viruses. The most detected viruses were human rhinovirus (26.9%, n=7) and coronavirus 19 (19.2%, n=5). A total of 11.5% of the patients had multiple viral infections. About 19 (42.2%) of the patients enrolled in our study had no viral pathogen detected. Conclusion We found that respiratory viruses contribute significantly to the development of neutropenic fever, as evidenced by the results of our prospective study. Individualizing infection treatment can reduce antibiotic use in immunocompromised patients. Thus, routine screening for viremia may be warranted in this clinical setting.