An Investigation of the Relationship between Henoch-Schönlein Purpura and Viral Infection in Korea Using the Health Insurance Database

(1) Background: This study investigated the epidemiology and viral connections of Henoch-Schönlein purpura (HSP) using information from the Korea Disease Control and Prevention Agency and the Health Insurance Review and Assessment database. (2) Method: Between 2016 and 2019, a total of 25,443 patients with HSP were identified, with 51.3% of patients under the age of 20 years and the highest incidence in March. (3) Results: The autoregressive integrated moving average model and Granger causality test were used to analyze the association between the virus positivity detection rate and HSP incidence. (4) Conclusions: The incidence of HSP was associated with rotavirus, bocavirus, parainfluenza virus, and respiratory syncytial virus in individuals under 20 years of age, whereas adenovirus, respiratory syncytial virus, and norovirus were associated with individuals above that age.

Human bocavirus 1 coinfection is associated with decreased cytokine expression in the rhinovirus-induced first wheezing episode in children

BACKGROUND

Rhinovirus (RV)-induced first wheezing episodes in children are associated with a markedly increased risk of asthma. Previous studies have suggested that human bocavirus 1 (HBoV1) may modify RV-induced immune responses in young children. We investigated cytokine profiles of sole RV- and dual RV-HBoV1-induced first wheezing episodes, and their association with severity and prognosis.

METHODS

Fifty-two children infected with only RV and nine children infected with dual RV-HBoV1, aged 3-23 months, with severe first wheezing episodes were recruited. At acute illness and 2 weeks later, peripheral blood mononuclear cells were isolated, and stimulated with anti-CD3/anti-CD28 in vitro. Multiplex ELISA was used to quantitatively identify 56 different cytokines at both study points. Patients were prospectively followed for 4 years.

RESULTS

The mean age of the children was 14.3 months, and 30% were sensitized. During the acute illness, the adjusted analyses revealed a decrease in the expression of IL-1b, MIP-1b, Regulated upon activation, normal T cell expressed and presumably secreted (CCL5), TNF-a, TARC, and ENA-78 in the RV-HBoV1 group compared with the RV group. In the convalescence phase, the RV-HBoV1 group was characterized by decreased expression of Fractalkine, MCP-3, and IL-8 compared to the RV group. Furthermore, the hospitalization time was associated with the virus group and cytokine response (interaction p < 0.05), signifying that increased levels of epidermal growth factor and MIP-1b were related with a shorter duration of hospitalization in the RV-HBoV1 coinfection group but not in the RV group.

CONCLUSIONS

Different cytokine response profiles were detected between the RV and the RV-HBoV1 groups. Our results show the idea that RV-induced immune responses may be suppressed by HBoV1.

Trend in respiratory viruses' activity in the COVID-19 area

OBJECTIVES

SARS-CoV-2 has impacted the detection of seasonal respiratory viruses. We retrospectively assessed the trend in the detection of 10 viruses in the COVID-19 area in 2 hospitals located in the Paris area.

METHODS

All patients positive for a respiratory virus in two hospitals from September 2016 to August 2021 were retrospectively included. The rate of RT-PCR positive for each virus was calculated for the 2020-2021 season and the 2019-2020 season in comparison to a baseline of 3 seasons, i.e. 2016-2017, 2017-2018, and 2018-2019.

RESULTS

Overall, 7,835 patients were tested positive from September 2016 to August 2021. The detection of respiratory virus dramatically falls on week-11 of 2020, as the number of RT-PCR performed. Then, 3 trends were identified: a) almost a disappearance for influenza; b) a 10-weeks delay in the seasonal outbreak for RSV; c) a persistence of circulation with variable activity for other viruses. In comparison to a baseline of three seasons (2016-2019), the rate of positive patients was lower during the 2020-2021 season for coronavirus (4.51% vs. 1.26%, P < 0.0001), adenovirus (1.93% vs. 1.34%, P = 0.14), bocavirus (0.58% vs. 0.11%, P = 0.08), and enterovirus (0.28% vs. 0.0%, P = 0.12). In contrast, the rate of hMPV-positive (1.92% vs. 2.83%, P = 0.03) and hPIV-positive (2.17% vs. 2.99%, P = 0.06) patients increased.

CONCLUSIONS

The fall in the number of respiratory viruses detected might be related to the lower number of tests performed and the implementation of non pharmaceutical intervention (NPI). Then, all viruses except influenza are detected, probably as a consequence of high adherence to influenza vaccines. Despite, a lower number of tests being performed, the rate of hMPV-positive and hPIV-positive patients increased suggesting an active circulation of these viruses. Altogether, these findings suggest a persistent circulation of common respiratory viruses all over the COVID-19 era.

Prevalence, molecular characterization, and clinical features of human bocavirus in children under 5 years of age with acute gastroenteritis admitted to a specialized children's hospital in Iran: A cross-sectional study

Background and Aims

Although some reports have confirmed the role of human bocavirus (HBoV) in respiratory infections, the importance of this virus in causing acute gastroenteritis has not yet been proven. This study aimed to determine the molecular prevalence of HBoV in children under 5 years old with gastroenteritis and to compare the clinical symptoms of HBoV-positive and -negative gastroenteritis cases.

Methods

A total of 100 stool samples were collected from children with gastroenteritis hospitalized in a pediatric hospital in Tehran, Iran. Demographic and clinical data were collected from patients' medical records. Viral genomic DNA was extracted from stool samples and amplified using the PCR assay. Finally, sequencing was used to determine the genotype of HBoV.

Results

The HBoV genome was detected in 14 samples (14%). The highest prevalence of HBoV was observed in the age range of 24-60 months (n = 5; 35.7%); However, no statistically significant relationship was observed between the prevalence of HBoV and age groups (p = 0.09). Nine (64.3%) and 5 (35.7%) HBoV-positive cases were boys and girls, respectively (p = 0.45). Fever, vomiting, and heartache were seen in 5 (35.7%), 3 (21.4%), and 1 (7.1%) HBoV-positive patients, respectively. Overall, no significant difference was observed in any of the investigated clinical manifestations between patients positive or negative for HBoV. Five HBoV-positive samples were subjected to sequencing and all five sequenced samples were genotype 3.

Conclusion

HBoV infections can be considered a risk factor for causing at least a portion of acute gastroenteritis cases in children under 5 years of age.

Structural Characterization of Canine Minute Virus, Rat and Porcine Bocavirus

Bocaparvovirus is an expansive genus of the Parvovirinae, with a wide range of vertebrate hosts. This study investigates Canine minute virus (CnMV), Rat bocavirus (RBoV), and Porcine bocavirus 1 (PBoV1). Both CnMV and PBoV1 have been found in gastrointestinal infections in their respective hosts, with CnMV responsible for spontaneous abortions in dogs, while PBoV has been associated with encephalomyelitis in piglets. The pathogenicity of the recently identified RBoV is currently unknown. To initiate the characterization of these viruses, their capsids structures were determined by cryo-electron microscopy at resolutions ranging from 2.3 to 2.7 Å. Compared to other parvoviruses, the CnMV, PBoV1, and RBoV capsids showed conserved features, such as the channel at the fivefold symmetry axis. However, major differences were observed at the two- and threefold axes. While CnMV displays prominent threefold protrusions, the same region is more recessed in PBoV1 and RBoV. Furthermore, the typical twofold axis depression of parvoviral capsids is absent in CnMV or very small in PBoV and RBoV. These capsid structures extend the structural portfolio for the Bocaparvovirus genus and will allow future characterization of these pathogens on a molecular level. This is important, as no antivirals or vaccines exist for these viruses.

Surveillance for Acute Respiratory Illnesses in Pediatric Chronic Care Facilities

Overall, 119 (33%) of 364 pediatric chronic care facility residents experienced 182 acute respiratory illnesses (ARIs) that met the surveillance definition which led to 31 (17%) emergency room visits, 34 (19%) acute care hospitalizations, and/or 25 (14%) ICU admissions. Continued PCR-positivity was observed in 35% of ARIs during follow-up testing.

Evaluation of human bocavirus as well as other well-known viral etiologic agents by PCR in the cerebrospinal fluid of children with clinical impression of viral meningoencephalitis referred to the Children's Medical Center in Tehran, Iran, from 2019 to 2020

Viral meningoencephalitis is one of the most important diseases that most commonly affect children. In many cases of viral meningoencephalitis, the underlying cause of the disease is not identified, raising the possibility of a variety of pathogens that are not routinely tested. Bocaviruses belong to a newly identified class of viruses that have been reported in some studies to be associated with viral encephalitis. In the present study, we investigated the prevalence of bocaviruses and other viruses in the patients suspected of having viral encephalitis and their associations with various demographic and clinical variables. Two hundred patients with suspected viral meningoencephalitis referred to Children's Medical Center were studied from 2019 to 2020. Age, sex, length of hospitalization, and course of the disease were gathered. Cerebrospinal fluid (CSF) samples were taken from the patients and subjected to biochemical examinations and PCR to identify the underlying cause. Bocaviruses were detected in none of the DNA samples extracted from the CSF specimens. The most identified organisms were mumps and enteroviruses. In 92% of cases, the underlying cause was not identified. PCR-based identification of the underlying causes of viral meningoencephalitis in CSF specimens was not successful in most cases. Bocavirus was not found in any of the collected CSF samples. Further studies are required for drawing more accurate conclusions.

Prevalence and Clinical Characterization of Bocavirus Infection in a Specialized Children's Hospital in Saudi Arabia

Aim

The aim of this study was to assess the prevalence and clinical characterization of bocavirus infection in patients admitted with respiratory symptoms to a specialized children’s hospital in Riyadh, Saudi Arabia.

Methods

This is a retrospective cross-sectional study that included children aged 0-14 years and was conducted over a two-year period (2017-2019). All data were gathered from an electronic information recording system, which included patients’ demographics, comorbidities, clinical presentation, complication, and duration of hospitalization.

Results

Among all patients (11,709) admitted to King Abdullah Specialized Children’s Hospital with predominant respiratory symptoms during the study period, 193 (1.6%) patients had bocavirus infections. Most of the patients were diagnosed in winter months. Cough was the primary presenting symptom (91.7%) followed by fever (83.4%). Gastrointestinal symptoms were also common (anorexia in 62% and vomiting in 39%). In 80% (n=154/193) of cases, bocavirus co-existed with other viruses, namely, human rhinovirus (45.8%), human adenovirus (31.2%), and respiratory syncytial virus type A (17.5%). Moreover, those who required oxygen supply stayed longer in the hospital (p<0.001) and were more likely to receive multiple medications such as bronchodilators (p<0.001), corticosteroids (p<0.001), and nebulized racemic epinephrine (p>0.05). Children infected with bocavirus and co-existing viruses were less likely to require oxygen supply (p<0.050).

Conclusion

Bocavirus infection is more common during winter months and predominantly affects respiratory and gastrointestinal systems in children. More studies are needed to evaluate the global impact of this recently recognized infection.

Best of most possible worlds: Hybrid gene therapy vectors based on parvoviruses and heterologous viruses

Parvoviruses and especially the adeno-associated virus (AAV) species provide an exciting and versatile platform for the rational design or molecular evolution of human gene-therapy vectors, documented by literature from over half a century, hundreds of clinical trials, and the recent commercialization of multiple AAV gene therapeutics. For the last three decades, the power of these vectors has been further potentiated through various types of hybrid vectors created by intra- or inter-genus juxtaposition of viral DNA and protein cis elements or by synergistic complementation of parvoviral features with those of heterologous, prokaryotic, or eukaryotic viruses. Here, we provide an overview of the history and promise of this rapidly expanding field of hybrid parvoviral gene-therapy vectors, starting with early generations of chimeric particles composed of a recombinant AAV genome encapsidated in shells of synthetic AAVs or of adeno-, herpes-, baculo-, or protoparvoviruses. We then dedicate our attention to two newer, highly promising types of hybrid vectors created via (1) pseudotyping of AAV genomes with bocaviral serotypes and capsid mutants or (2) packaging of AAV DNA into, or tethering of entire vector particles to, bacteriophages. Finally, we conclude with an outlook summarizing critical requirements and improvements toward clinical translation of these original concepts.

Prevalence and Molecular Characterization of Human Bocavirus Detected in Croatian Children with Respiratory Infection

Human bocavirus (HBoV) 1 is considered an important respiratory pathogen, while the role of HBoV2-4 in clinical disease remains somewhat controversial. Since, they are characterized by a rapid evolution, worldwide surveillance of HBoVs’ genetics is necessary. This study explored the prevalence of HBoV genotypes in pediatric patients with respiratory tract infection in Croatia and studied their phylogeny. Using multiplex PCR for 15 respiratory viruses, we investigated 957 respiratory samples of children up to 18 years of age with respiratory tract infection obtained from May 2017 to March 2021 at two different hospitals in Croatia. Amplification of HBoV near-complete genome or three overlapping fragments was performed, sequenced, and their phylogenetic inferences constructed. HBoV was detected in 7.6% children with a median age of 1.36 years. Co-infection was observed in 82.2% samples. Sequencing was successfully performed on 29 HBoV positive samples, and all belonged to HBoV1. Croatian HBoV1 sequences are closely related to strains isolated worldwide, and no phylogenetic grouping based on mono- or co-infection cases or year of isolation was observed. Calculated rates of evolution for HBoV1 were 10⁻⁴ and 10⁻⁵ substitutions per site and year. Recombination was not detected among sequences from this study.

Seasonal Coronaviruses and Other Neglected Respiratory Viruses: A Global Perspective and a Local Snapshot

Respiratory viral infections are the leading cause of morbidity and mortality in the world; however, there are several groups of viruses that are insufficiently routinely sought for, and can thus be considered neglected from a diagnostic and clinical standpoint. Timely detection of seasonality of certain respiratory viruses (e.g., enveloped viruses such as seasonal coronaviruses) in the local context can aid substantially in targeted and cost-effective utilization of viral diagnostic approaches. For the other, non-enveloped and year-round viruses (i.e., rhinovirus, adenovirus, and bocavirus), a continuous virological diagnosis needs to be implemented in clinical laboratories to more effectively address the aetiology of respiratory infections, and assess the overall impact of these viruses on disease burden. While the coronavirus disease 2019 (COVID-19) pandemic is still actively unfolding, we aimed to emphasize the persistent role of seasonal coronaviruses, rhinoviruses, adenoviruses and bocaviruses in the aetiology of respiratory infections. Consequently, this paper concentrates on the burden and epidemiological trends of aforementioned viral groups on a global level, but also provides a snapshot of their prevalence patterns in Croatia in order to underscore the potential implications of viral seasonality. An overall global prevalence in respiratory tract infections was found to be between 0.5 and 18.4% for seasonal coronaviruses, between 13 and 59% for rhinoviruses, between 1 and 36% for human adenoviruses, and between 1 and 56.8% for human bocaviruses. A Croatian dataset on patients with respiratory tract infection and younger than 18 years of age has revealed a fairly high prevalence of rhinoviruses (33.4%), with much lower prevalence of adenoviruses (15.6%), seasonal coronaviruses (7.1%), and bocaviruses (5.3%). These insights represent a relevant discussion point in the context of the COVID-19 pandemic where the testing of non-SARS-CoV-2 viruses has been limited in many settings, making the monitoring of disease burden associated with other respiratory viruses rather difficult.

Severe Human Bocavirus-Associated Pneumonia in Adults at a Referral Hospital, Seoul, South Korea

We report a case series of severe human bocavirus–associated pneumonia in adults in Seoul, South Korea. The virus accounted for 0.5% of all severe pneumonia cases. Structural lung disease and hematologic malignancy were common underlying diseases. Overall death rate was 54.5%. Higher death rates were associated with co-infection (83.3%) and immunocompromise (80.0%).

Characterization of the GBoV1 Capsid and Its Antibody Interactions

Human bocavirus 1 (HBoV1) has gained attention as a gene delivery vector with its ability to infect polarized human airway epithelia and 5.5 kb genome packaging capacity. Gorilla bocavirus 1 (GBoV1) VP3 shares 86% amino acid sequence identity with HBoV1 but has better transduction efficiency in several human cell types. Here, we report the capsid structure of GBoV1 determined to 2.76 Å resolution using cryo-electron microscopy (cryo-EM) and its interaction with mouse monoclonal antibodies (mAbs) and human sera. GBoV1 shares capsid surface morphologies with other parvoviruses, with a channel at the 5-fold symmetry axis, protrusions surrounding the 3-fold axis and a depression at the 2-fold axis. A 2/5-fold wall separates the 2-fold and 5-fold axes. Compared to HBoV1, differences are localized to the 3-fold protrusions. Consistently, native dot immunoblots and cryo-EM showed cross-reactivity and binding, respectively, by a 5-fold targeted HBoV1 mAb, 15C6. Surprisingly, recognition was observed for one out of three 3-fold targeted mAbs, 12C1, indicating some structural similarity at this region. In addition, GBoV1, tested against 40 human sera, showed the similar rates of seropositivity as HBoV1. Immunogenic reactivity against parvoviral vectors is a significant barrier to efficient gene delivery. This study is a step towards optimizing bocaparvovirus vectors with antibody escape properties.

Human bocavirus and metapneumovirus in acute wheezing in children-Is there a link with atopy?

INTRODUCTION

Viral respiratory tract infections are the leading cause of acute wheezing in children with a significant risk of hospital admission, risk of recurrence and subsequent asthma. Human respiratory syncytial virus (RSV) and human rhinovirus (RV) in childhood wheezing are widely studied; however, accessible PCR assays enabled diagnosis of other pathogens, including bocavirus (hBOV) and metapneumovirus (hMPV).

OBJECTIVES

The aim of the study was to evaluate the prevalence of respiratory viruses in children hospitalized for acute wheezing along with demographic and clinical data.

METHODS

We enrolled 101 children, n = 50 (49.5%) with wheezy bronchitis, n = 34 (33.7%) with acute bronchiolitis and n = 17 (16.8%) with exacerbation of asthma; (median age 1.41 ± 2.84 years). Multiplex real-time PCR assay was used for virus detection.

RESULTS

One or more viruses were detected in 83.2% subjects: RSV in 44.6%, followed by RV (23.8%), hBOV and hMPV (both 11.9%); other viruses were less frequent (<8%). Viral coinfection was found in 38 (37.6%) of children. ANCOVA analysis revealed significantly higher total IgE concentrations in the hMPV-positive subgroup compared to RSV (34 kU/L vs 12.7 kU/L; P = .009) and RV (13.3 kU/L, P = .022). For both hMPV and hBOV an association with atopic dermatitis (AD) was observed: aOR for hMPV and AD was 5.6 (95%CI: 1.4-22.7; P = .016) and 4.7 for hBOV and AD (95%CI: 1.3-18; P = .024).

CONCLUSION

Viral detection ratio in wheezy respiratory tract infections in Polish children is high (83.2%), with both hBOV and hMPV at 11.9% The results also suggest possible relationship of hBOV wheezy infection with nonspecific markers of atopy in children.

High prevalence of SARS-CoV-2 and influenza A virus (H1N1) coinfection in dead patients in Northeastern Iran

In the last months of 2019, an outbreak of fatal respiratory disease started in Wuhan, China, and quickly spread to other parts of the world. It was named COVID-19, and to date, thousands of cases of infection and death are reported worldwide. This disease is associated with a wide range of symptoms, which makes accurate diagnosis of it difficult. During previous severe acute respiratory syndrome (SARS) pandemic in 2003, researchers found that the patients with fever, cough, or sore throat had a 5% influenza virus-positive rate. This finding made us think that the wide range of symptoms and also relatively high prevalence of death in our patients may be due to the coinfection with other viruses. Thus, we evaluated the coinfection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with other respiratory viruses in dead patients in North Khorasan. We evaluated the presence of influenza A/B virus, human metapneumovirus, bocavirus, adenovirus, respiratory syncytial virus (RSV), and parainfluenza viruses in 105 SARS-CoV-2 positive dead patients, using polymerase chain reaction (PCR) and reverse transcription PCR tests. We found coinfection with influenza virus in 22.3%, RSV, and bocavirus in 9.7%, parainfluenza viruses in 3.9%, human metapneumovirus in 2.9%, and finally adenovirus in 1.9% of SARS-CoV-2 positive dead cases. Our findings highlight a high prevalence of coinfection with influenza A virus and the monopoly of coinfection with Human metapneumovirus in children.

Human bocavirus (HBoV) in Kuwait: molecular epidemiology and clinical outcome of the virus among patients with respiratory diseases

Introduction. Globally, human bocavirus (HBoV) has been detected in respiratory samples from patients suffering from upper and lower respiratory diseases. In Kuwait, little is known about the epidemiological and clinical characterization of the virus and genetic characterization of the virus as a respiratory pathogen is unknown.Aim. This study aims to explore the molecular epidemiology and clinical features of HBoV isolates in patients with respiratory diseases.Methodology. Retrospectively, between 2018 and 2020, 5941 respiratory samples from patients with respiratory diseases were screened for respiratory viruses using multiplex real-time PCR. Samples that were positive for HBoV were then subjected to NP1 and VP1/PV2 phylogenetic analysis.Results. HBoV was detected in 1.9 % of the patients, with a peak incidence of infection among children <1 year old. Co-infection with other respiratory viruses was observed in 56.8 % of HBoV-positive patients. Fever, cough and respiratory distress were the most common clinical features of HBoV infection. Phylogenetic analysis of the Kuwaiti HBoV isolates revealed that all the isolates were of the HBoV-1 genotype, with slight sequence variations among the isolates.Conclusion. This study illustrated the predominance of the HBoV-1 genotype in patients with respiratory diseases in Kuwait with minimal genetic variability. It also highlighted the clinical features of HBoV-1 infection, verifying its role in respiratory diseases.

No Correlation Between Nasopharyngeal Human Bocavirus 1 Genome Load and mRNA Detection or Serology in Adeno-/Tonsillectomy Patients

Human bocavirus 1 (HBoV1) can persist in nasopharynx and tonsils. Using HBoV1 serology, reverse-transcription polymerase chain reaction (PCR) for detecting messenger RNA (mRNA) and quantitative PCR for HBoV1 genome load count, we studied to what extent the HBoV1 DNA loads in nasopharynx correlate with acute infection markers. Tonsillar tissue, nasopharyngeal aspirate, and serum were obtained from 188 elective adeno-/tonsillectomy patients. Relatively high loads of HBoV1 DNA were detected in the nasopharynx of 14 (7%) primarily asymptomatic subjects with negative mRNA and/or serodiagnostic results. Quantitative HBoV1 DNA PCR may have lower specificity than HBoV1 mRNA detection for diagnosing symptomatic infection.

Impact of Natural or Synthetic Singletons in the Capsid of Human Bocavirus 1 on Particle Infectivity and Immunoreactivity

Human bocavirus 1 (HBoV1) is a parvovirus that gathers increasing attention due to its pleiotropic role as a pathogen and emerging vector for human gene therapy. Curiously, albeit a large variety of HBoV1 capsid variants has been isolated from human samples, only one has been studied as a gene transfer vector to date. Here, we analyzed a cohort of HBoV1-positive samples and managed to PCR amplify and sequence 29 distinct HBoV1 capsid variants. These differed from the originally reported HBoV1 reference strain in 32 nucleotides or four amino acids, including a frequent change of threonine to serine at position 590. Interestingly, this T590S mutation was associated with lower viral loads in infected patients. Analysis of the time course of infection in two patients for up to 15 weeks revealed a gradual accumulation of T590S, concurrent with drops in viral loads. Surprisingly, in a recombinant vector context, T590S was beneficial and significantly increased titers compared to that of T590 variants but had no major impact on their transduction ability or immunoreactivity. Additional targeted mutations in the HBoV1 capsid identified several residues that are critical for transduction, capsid assembly, or DNA packaging. Our new findings on the phylogeny, infectivity, and immunoreactivity of HBoV1 capsid variants improve our understanding of bocaviral biology and suggest strategies to enhance HBoV1 gene transfer vectors.IMPORTANCE The family of Parvoviridae comprises a wide variety of members that exhibit a unique biology and that are concurrently highly interesting as a scaffold for the development of human gene therapy vectors. A most notable example is human bocavirus 1 (HBoV1), which we and others have recently harnessed to cross-package and deliver recombinant genomes derived from another parvovirus, the adeno-associated virus (AAV). Here, we expanded the repertoire of known HBoV1 variants by cloning 29 distinct HBoV1 capsid sequences from primary human samples and by analyzing their properties as AAV/HBoV1 gene transfer vectors. This led to our discovery of a mutational hot spot at HBoV1 capsid position 590 that accumulated in two patients during natural infection and that lowers viral loads but increases vector yields. Thereby, our study expands our current understanding of HBoV1 biology in infected human subjects and concomitantly provides avenues to improve AAV/HBoV1 gene transfer vectors.

Molecular screening of the human parvoviruses B19 and bocavirus 1 in the study of congenital diseases as applied to symptomatic pregnant women and children

Introduction

B19 virus (B19V) and bocavirus 1 (HBoV1) are human pathogenic parvoviruses that are prevalent worldwide and are responsible for a diverse and not yet fully established spectrum of clinical manifestations.

Objective

To screen B19V and HBoV1 in patients with clinical manifestations associated with acquisition of the infection during gestation.

Methods

A retrospective, observational study was performed that included serum samples from patients without a previous known aetiology. B19V and HBoV1 were determined by end-point PCR. Positive samples were genotyped.

Results

A total of 106 serum samples were analysed, 61 from pregnant women and 45 from neonates and paediatric patients. None were positive for HBoV1, while B19V was detected in 37/106 [34.9 %, 95 % confidence interval (CI): 26.5–44.4] of the samples studied. In the group of pregnant women, 28/61 (45.9 %, 95 % CI: 34.0–58.3) were B19V-positive, and 2 of them had foetal anaemia followed by hydrops and foetal death, 3 were associated with a history of recurrent pregnancy loss and there was 1 case of spontaneous abortion. B19V was also detected in cases of maternal febrile exanthema, polyhydramnios, oligohydramnios and foetal ascites. In the group of children, 9/45 (20.0 %, 95 % CI: 10.9–33.8) neonatal patients were B19V-positive, and this was associated with foetal hydrops, TORCH syndrome and cardiac alterations. The nucleotide sequences analysed confirmed the identity of B19V genotype 1.

Conclusions

We found no evidence to indicate the presence of HBoV1 in maternal blood or in the newborns/paediatric patients (hence providing no support for the supposed vertical transmission). On the other hand, the high frequency of B19V in the pathologies studied indicates the importance of molecular diagnosis in both the mother and the child. Future efforts should contribute to early detection and characterization of infections.

Novel Chimeric Gene Therapy Vectors Based on Adeno-Associated Virus and Four Different Mammalian Bocaviruses

Parvoviruses are highly attractive templates for the engineering of safe, efficient, and specific gene therapy vectors, as best exemplified by adeno-associated virus (AAV). Another candidate that currently garners increasing attention is human bocavirus 1 (HBoV1). Notably, HBoV1 capsids can cross-package recombinant (r)AAV2 genomes, yielding rAAV2/HBoV1 chimeras that specifically transduce polarized human airway epithelia (pHAEs). Here, we largely expanded the repertoire of rAAV/BoV chimeras, by assembling packaging plasmids encoding the capsid genes of four additional primate bocaviruses, HBoV2–4 and GBoV (Gorilla BoV). Capsid protein expression and efficient rAAV cross-packaging were validated by immunoblotting and qPCR, respectively. Interestingly, not only HBoV1 but also HBoV4 and GBoV transduced pHAEs as well as primary human lung organoids. Flow cytometry analysis of pHAEs revealed distinct cellular specificities between the BoV isolates, with HBoV1 targeting ciliated, club, and KRT5+ basal cells, whereas HBoV4 showed a preference for KRT5+ basal cells. Surprisingly, primary human hepatocytes, skeletal muscle cells, and T cells were also highly amenable to rAAV/BoV transduction. Finally, we adapted our pipeline for AAV capsid gene shuffling to all five BoV isolates. Collectively, our chimeric rAAV/BoV vectors and bocaviral capsid library represent valuable new resources to dissect BoV biology and to breed unique gene therapy vectors.

Minute Virus of Canines NP1 Protein Interacts with the Cellular Factor CPSF6 To Regulate Viral Alternative RNA Processing

The NP1 protein of minute virus of canines (MVC) governs production of the viral capsid proteins via its role in pre-mRNA processing. NP1 suppresses polyadenylation and cleavage at its internal site, termed the proximal polyadenylation (pA)p site, to allow accumulation of RNAs that extend into the capsid gene, and it enhances splicing of the upstream adjacent third intron, which is necessary to properly enter the capsid protein open reading frame. We find the (pA)p region to be complex. It contains redundant classical cis-acting signals necessary for the cleavage and polyadenylation reaction and splicing of the adjacent upstream third intron, as well as regions outside the classical motifs that are necessary for responding to NP1. NP1, but not processing mutants of NP1, bound to MVC RNA directly. The cellular RNA processing factor CPSF6 interacted with NP1 in transfected cells and participated with NP1 to modulate its effects. These experiments further characterize the role of NP1 in parvovirus gene expression.IMPORTANCE The Parvovirinae are small nonenveloped icosahedral viruses that are important pathogens in many animal species, including humans. Unlike other parvoviruses, the bocavirus genus controls expression of its capsid proteins via alternative RNA processing, by both suppressing polyadenylation at an internal site, termed the proximal polyadenylation (pA)p site, and by facilitating splicing of an upstream adjacent intron. This regulation is mediated by a small genus-specific protein, NP1. Understanding the cis-acting targets of NP1, as well as the cellular factors with which it interacts, is necessary to more clearly understand this unique mode of parvovirus gene expression.

The Human Bocavirus 1 NP1 Protein Is a Multifunctional Regulator of Viral RNA Processing

Human bocavirus 1 (HBoV1) encodes a genus-specific protein, NP1, which regulates viral alternative pre-mRNA processing. Similar to NP1 of the related bocavirus minute virus of canine (MVC), HBoV1 NP1 suppressed cleavage and polyadenylation of RNAs at the viral internal polyadenylation site (pA)p. HBoV1 (pA)p is a complex region. It contains 5 significant cleavage and polyadenylation sites, and NP1 was found to regulate only the three of these sites that are governed by canonical AAUAAA hexamer signals. HBoV1 NP1 also facilitated splicing of the upstream intron adjacent to (pA)p. Alternative polyadenylation and splicing of the upstream intron were independent of each other, functioned efficiently within an isolated transcription unit, and were responsive independent of NP1. Characterization of HBoV1 NP1 generalizes its function within the genus Bocaparvovirus, uncovers important differences, and provides important comparisons with MVC NP1 for mechanistic and evolutionary considerations.IMPORTANCE The Parvovirinae are small nonenveloped icosahedral viruses that are important pathogens in many animal species, including humans. The NP1 protein of human bocavirus 1 (HBoV1), similar to NP1 of the bocavirus minute virus of canine (MVC), regulates viral alternative RNA processing by both suppressing polyadenylation at an internal site, (pA)p, and facilitating splicing of an upstream adjacent intron. These effects allow both extension into the capsid gene and splicing of the viral pre-mRNA that correctly registers the capsid gene open reading frame. Characterization of HBoV1 NP1 generalizes this central mode of parvovirus gene regulation to another member of the bocavirus genus and uncovers both important similarities and differences in function compared to MVC NP1 that will be important for future comparative studies.

Detection of Human Bocavirus Species 2 and 3 in Bivalve Shellfish in Italy

Human bocavirus (HBoV) has been shown to be a common cause of respiratory infections and gastroenteritis in children. Recently, HBoVs have been detected in sewage and river waters in Italy and worldwide. However, studies on their presence in other water environments and in bivalve mollusks are not yet available. In this study, 316 bivalve shellfish samples collected in three Italian regions over a 6-year period (2012 to 2017) were analyzed by nested PCR and sequencing using broad-range primer pairs targeting the capsid proteins VP1 and VP2 of HBoV. The virus was detected in 27 samples (8.5% of the total samples), and a statistically significant difference was found within the three regions. A further 13 samples, collected in geographic and temporal proximity to positive samples, were included in the study to assess the spread of HBoV in shellfish production areas at the time of contamination. Twelve of these additional samples were found to be positive for HBoV. All positive samples in this study were characterized as HBoV species 2 (17 samples; 8 different sequences) or species 3 (22 samples; 4 different sequences). This study reports the occurrence of HBoV in bivalve shellfish and shows evidence of considerable spatial spread of the virus throughout shellfish production areas. Further studies are needed to elucidate both the role of HBoV as an agent of gastroenteritis and the risk for foodborne transmission of this virus.IMPORTANCE Human bocavirus is recognized as an important cause of acute respiratory tract infections and has recently been considered an etiological agent of gastroenteritis in the pediatric population. Our findings document that HBoVs are detected in bivalve shellfish with a relevant prevalence and suggest that an assessment of the risk for foodborne transmission of these viruses should be undertaken.

Canine Bocavirus Type 2 Infection Associated With Intestinal Lesions

Bocaviruses are small nonenveloped DNA viruses belonging to the Bocaparvovirus genus of the Parvoviridae family and have been linked to both respiratory and enteric disease in humans and animals. To date, 3 bocaviruses, canine bocaviruses 1 to 3 (CBoV-1-3), have been shown to affect dogs with different disease manifestations reported for infected animals. We used next-generation sequencing to identify a novel strain of canine CBoV-2 (CBoV TH-2016) in a litter of puppies that died in Thailand from acute dyspnea and hemoptysis, for which no causal pathogen could be identified in routine assays. Analysis of the complete coding sequences of CBoV TH-2016 showed that this virus was most closely related to a strain previously identified in South Korea (isolate 14D193), with evidence of genetic recombination in the VP2 gene with related strains from South Korea and Hong Kong. Use of quantitative polymerase chain reaction showed the presence of CBoV TH-2016 in several tissues, suggesting hematogenous virus spread, while only intestinal tissue was found to be positive by in situ hybridization and electron microscopy. Histologic small intestinal lesions associated with CBoV TH-2016 infection were eosinophilic intranuclear inclusion bodies within villous enterocytes without villous atrophy or fusion, similar to those previously considered pathognomonic for CBoV-1 infection. Therefore, this study provides novel insights in the pathogenicity of canine bocavirus infections and suggests that a novel recombinant CBoV-2 may result in atypical findings of CBoV infection. Although the specific cause of death of these puppies remained undetermined, a contributory role of enteric CBoV TH-2016 infection is possible.

Identification of an enterovirus recombinant with a torovirus-like gene insertion during a diarrhea outbreak in fattening pigs

Diarrhea outbreaks in pig farms have raised major concerns in Europe and USA, as they can lead to dramatic pig losses. During a suspected outbreak in Belgium of porcine epidemic diarrhea virus (PEDV), we performed viral metagenomics to assess other potential viral pathogens. Although PEDV was detected, its low abundance indicated that other viruses were involved in the outbreak. Interestingly, a porcine bocavirus and several enteroviruses were most abundant in the sample. We also observed the presence of a porcine enterovirus genome with a gene insertion, resembling a C28 peptidase gene found in toroviruses, which was confirmed using re-sequencing, bioinformatics, and proteomics approaches. Moreover, the predicted cleavage sites for the insertion suggest that this gene was being expressed as a single protein, rather than a fused protein. Recombination in enteroviruses has been reported as a major mechanism to generate genetic diversity, but gene insertions across viral families are rather uncommon. Although such inter-family recombinations are rare, our finding suggests that these events may significantly contribute to viral evolution.

Viral gut metagenomics of sympatric wild and domestic canids, and monitoring of viruses: Insights from an endangered wolf population

Animal host-microbe interactions are a relevant concern for wildlife conservation, particularly regarding generalist pathogens, where domestic host species can play a role in the transmission of infectious agents, such as viruses, to wild animals. Knowledge on viral circulation in wild host species is still scarce and can be improved by the recent advent of modern molecular approaches. We aimed to characterize the fecal virome and identify viruses of potential conservation relevance of diarrheic free-ranging wolves and sympatric domestic dogs from Central Portugal, where a small and threatened wolf population persists in a highly anthropogenically modified landscape. Using viral metagenomics, we screened diarrheic stools collected from wolves (n = 8), feral dogs (n = 4), and pet dogs (n = 6), all collected within wolf range. We detected novel highly divergent viruses as well as known viral pathogens with established effects on population dynamics, including canine distemper virus, a novel bocavirus, and canine minute virus. Furthermore, we performed a 4-year survey for the six wolf packs comprising this endangered wolf population, screening 93 fecal samples from 36 genetically identified wolves for canine distemper virus and the novel bocavirus, previously identified using our metagenomics approach. Our novel approach using metagenomics for viral screening in noninvasive samples of wolves and dogs has profound implications on the knowledge of both virology and wildlife diseases, establishing a complementary tool to traditional screening methods for the conservation of threatened species.

Human bocavirus induces apoptosis and autophagy in human bronchial epithelial cells

Human bocavirus (HBoV) is classified in the Bocavirus genus within the Parvoviridae family, first identified from children with respiratory diseases. Previous studies have investigated the stimulating effect of HBoV on cell apoptosis and autophagy. In the present study, human bronchial epithelial cells (HBECs) were utilized to examine the mechanism of HBoV recombination expressing vector (pWHL-1) on the promotion of cell apoptosis and autophagy. The results from the present study indicated that pWHL-1 inhibited the proliferation of HBECs in a time-dependent manner. Additionally, pWHL-1induced apoptosis, as substantiated by an increased apoptotic rate and presence of autophagosomes. Following pWHL-1 transfection, proliferating cell nuclear antigen, caspase-3 and B cell lymphoma 2 (Bcl-2) protein expression levels were decreased, with the exception of Bcl-2 associated × (Bax) protein, which increased. mRNA and protein expression levels of microtubule-associated protein 1A/1B-light chain 3 (LC3) II and autophagy protein 5 were increased in pWHL-1-transfected HBECs, whereas, the mRNA and protein levels of LC3I and sequestosome 1 were decreased. Notably, pWHL-1 also enhanced the activation of p53 and inhibited AKT activation in HBECs. Results from the present study suggest that pWHL-1 induces apoptosis and autophagy, thus providing a novel insight into the effect of HBoV and its uses in respiratory diseases.

Parvovirus Expresses a Small Noncoding RNA That Plays an Essential Role in Virus Replication

Human bocavirus 1 (HBoV1) belongs to the species Primate bocaparvovirus of the genus Bocaparvovirus of the Parvoviridae family. HBoV1 causes acute respiratory tract infections in young children and has a selective tropism for the apical surface of well-differentiated human airway epithelia (HAE). In this study, we identified an additional HBoV1 gene, bocavirus-transcribed small noncoding RNA (BocaSR), within the 3' noncoding region (nucleotides [nt] 5199 to 5338) of the viral genome of positive sense. BocaSR is transcribed by RNA polymerase III (Pol III) from an intragenic promoter at levels similar to that of the capsid protein-coding mRNA and is essential for replication of the viral DNA in both transfected HEK293 and infected HAE cells. Mechanistically, we showed that BocaSR regulates the expression of HBoV1-encoded nonstructural proteins NS1, NS2, NS3, and NP1 but not NS4. BocaSR is similar to the adenovirus-associated type I (VAI) RNA in terms of both nucleotide sequence and secondary structure but differs from it in that its regulation of viral protein expression is independent of RNA-activated protein kinase (PKR) regulation. Notably, BocaSR accumulates in the viral DNA replication centers within the nucleus and likely plays a direct role in replication of the viral DNA. Our findings reveal BocaSR to be a novel viral noncoding RNA that coordinates the expression of viral proteins and regulates replication of viral DNA within the nucleus. Thus, BocaSR may be a target for antiviral therapies for HBoV and may also have utility in the production of recombinant HBoV vectors.IMPORTANCE Human bocavirus 1 (HBoV1) is pathogenic to humans, causing acute respiratory tract infections in young children. In this study, we identified a novel HBoV1 gene that lies in the 3' noncoding region of the viral positive-sense genome and is transcribed by RNA polymerase III into a noncoding RNA of 140 nt. This bocavirus-transcribed small RNA (BocaSR) diverges from both adenovirus-associated (VA) RNAs and Epstein-Barr virus-encoded small RNAs (EBERs) with respect to RNA sequence, representing a third species of this kind of Pol III-dependent viral noncoding RNA and the first noncoding RNA identified in autonomous parvoviruses. Unlike the VA RNAs, BocaSR localizes to the viral DNA replication centers of the nucleus and is essential for expression of viral nonstructural proteins independent of RNA-activated protein kinase R and replication of HBoV1 genomes. The identification of BocaSR and its role in virus DNA replication reveals potential avenues for developing antiviral therapies.

Bocavirus infection following paediatric liver transplantation

HBoV is an emergent virus, which is frequently detected as a co-infective agent. However, it can cause disease on its own. It is associated with respiratory and diarrhoeal illness in children and adults, whether immunocompetent or immunocompromised. We report HBoV infection in a child post-liver transplantation, who presented with persistent fever and mild tachypnea, 3 weeks after a successful transplant. She recovered spontaneously with no graft dysfunction.

Pneumomediastinum, pneumorrhachis and subcutaneous emphysema associated with viral infections: Report of three cases

Spontaneous pneumomediastinum is usually secondary to alveolar rupture in the pulmonary interstitium, associated with subcutaneous emphysema and occasionally with pneumothorax, but is rarely associated with pneumorrhachis. The leaked air into the pulmonary perivascular interstitium follows the path of least resistance from the mediastinum to the fascial planes of the neck. Air freely communicates via the neural foramina and collects in the epidural space. Pneumorrhachis is defined as the presence of air in the spinal canal, either in the intradural and/or extradural spaces. It is a very rare clinical entity and mostly asymptomatic, hence most probably underdiagnosed. Many pathological and physiological events can lead to alveolar rupture, and these clinical findings can be related to various, mainly traumatic and iatrogenic etiologies. Herein we report three cases of pneumomediastinum, subcutaneous emphysema, interstitial emphysema and pneumorrhachis in two cases, which were related to rhinovirus, human bocavirus and respiratory syncytial virus infection.

Detection and characterisation of novel bocavirus (genus Bocaparvovirus) and gastroenteritis viruses from asymptomatic pigs in Ireland

Background

Livestock animals have been the assumed source of several human epidemics in recent years, for example, influenza H1N1, rotavirus G8/G9, and MERS-CoV. Surveillance of novel viruses in animals is essential to evaluate the risk to human and animal health and to determine any economic impact, for example, failure to thrive. There is a paucity of data regarding detection and characterisation of gastroenteritis viruses, particularly novel viruses, in porcines in Ireland. Recently, a number of small novel porcine DNA viruses have emerged globally, for example, torque teno sus virus, porcine bocavirus, and parvoviruses 2 & 4, and little is known about the biology and potential pathogenicity of these viruses. Bocaparvovirus is a genetically distinct group of viruses which has been recently detected in humans and animals.

Methods

In this study, the presence of gastroenteritis viruses (rotavirus A, porcine circovirus, adenovirus, and porcine bocavirus) was investigated in a selection of archived faecal samples from asymptomatic piglets from a commercial farm in Ireland. A total of 104 specimens were pooled and screened using conventional molecular techniques (PCR and RT-PCR), a subset of specimens (n=44) were then examined individually. Viral diversity was then investigated using statistical and phylogenetic techniques.

Results

Initial screening showed a high prevalence of PBoV in this farm, with the formation of three distinct groups in phylogenetic analysis. Other viruses were also investigated in this study with the first report of PCV, PAdV and lineage I G5 RVA in Ireland. Some specimens contained >1 virus, with statistical analysis indicating a strong correlation for mixed infections of PBoV and PAdV on this farm.

Conclusion

Investigating the diversity of circulating enteric viruses on Irish porcine farms is important to improve the prophylactic tools available and to facilitate the early detection of changes in circulating viruses.

Human Bocavirus 1 Primary Infection and Shedding in Infants

BACKGROUND

Human bocavirus 1 (HBoV-1) is frequently detected in young children. The role of HBoV-1 in respiratory illness is unclear, owing to frequent detection in asymptomatic children.

METHODS

Weekly oral fluid samples from a longitudinal cohort of infants were tested by quantitative polymerase chain reaction for HBoV-1 DNA. Symptoms during HBoV-1 primary shedding events were compared to those during 14-day control periods occurring 1 month prior to and following the primary event. Eight single-nucleotide polymorphisms were analyzed to assess HBoV-1 variants.

RESULTS

Sixty-six of 87 children (76%), followed for at least 18 months from birth, had a primary HBoV-1 infection. HBoV-1 was consistently detected for >1 month (maximum duration, 402 days) following 42 of 66 primary shedding events. Children were more likely to experience new cough symptoms (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.4-5.5) and to visit a healthcare provider (OR, 2.8; 95% CI, 1.02-7.7) during the 14 days surrounding the time of initial detection of HBoV-1. Recurrent HBoV-1 shedding events were found in 33 children (50%). Twelve of 48 children with HBoV-1 variant data had multiple viral allelic patterns over time.

CONCLUSIONS

HBoV-1 primary shedding events are associated with mild respiratory illness with subsequent prolonged detection of HBoV-1 DNA for up to a year. HBoV-1 reinfection contributes to long-term shedding.

'Human bocavirus in Pakistani children with gastroenteritis'

Human Bocaviruses (HBoV) have been detected in human respiratory and gastrointestinal infections worldwide. Four genotypes of HBoV (HBoV1-4) have been described; HBoV-1 is associated with respiratory tract infections while HBoV-2, -3, and -4 genotypes are considered as entero-pathogenic although the exact role largely remains unclear. The global prevalence of HBoV has been reported, but the epidemiological data from Pakistan is largely unavailable to date. This study was conducted to understand the genetic diversity and disease prevalence of HBoV in hospitalized Pakistani children with acute diarrhea. During 2009, a total of 365 stool samples were collected from children hospitalized with gastrointestinal symptoms (as per WHO case definitions) at Rawalpindi General Hospital, Pakistan. Demographic and clinical data were recorded using a standardized questionnaire. The samples were tested for HBoV and rotavirus using real-time RT-PCR and ELISA, respectively. There were 47 (13%) samples positive for HBoV with 98% (n = 46) showing co-infection with rotavirus. HBoV-1 was the most frequently detected and was found in 94% samples followed by HBoV-2 and HBoV-3 genotypes. The mean age of infected children was 7.57 ± 5.4 months while detection was more frequent in males (n = 32, 68%). All cases recovered after 2.43 ± 1.0 mean days of treatment. On phylogenetic analysis, HBoV strains from Pakistan clustered closely with viruses from neighboring Bangladesh and China. These findings represent the first known epidemiological study in Pakistan to investigate the role of HBoV in acute gastroenteritis. The clinical data demonstrates that HBoV is not significantly associated with gastroenteritis alone and predominantly co-infections with rotavirus are found.

The first wheezing episode: respiratory virus etiology, atopic characteristics, and illness severity

BACKGROUND

Susceptibility to early rhinovirus-induced wheezing has been recognized as an important risk factor for childhood asthma, but data on the first wheezing episode are limited. The aim of this selected population study was to investigate virus etiology, atopic characteristics, and illness severity, as well as their interrelation, among first-time wheezing children.

METHODS

We studied 111 first-time wheezing children aged between 3 and 23 months (88/23 in-/outpatients). The investigated factors included atopy, food, perennial and aeroallergen sensitization, eczema, atopic eczema, elevated blood eosinophil count, and parental allergic rhinitis, asthma, and smoking. Nasopharyngeal aspirates were analyzed for adenovirus, coronaviruses, enteroviruses, bocavirus-1 (also serologically confirmed), influenza viruses, metapneumovirus, parainfluenza viruses, rhinovirus, and respiratory syncytial virus using PCR methods.

RESULTS

The mean age of the study patients was 12 months (standard deviation 6.0). Atopic characteristics could be found in 56%, atopic eczema in 16%, and sensitization in 23% of the cases. In all samples (100%), ≥1 viruses were detected as follows: rhinovirus (76%), respiratory syncytial virus (29%), bocavirus (18%, acute infections), and other viruses <10% each. Virus coinfections occurred in 38% of the children. Rhinovirus infection was positively associated with age, blood eosinophil count, eczema, and duration of cough, as well as parental allergic rhinitis and smoking but negatively associated with virus coinfection (all p < 0.05).

CONCLUSIONS

A respiratory virus infection can be detected in all first-time wheezing children. Rhinovirus dominated the findings and was linked to atopic characteristics, prolonged cough, and parental smoking.

Human bocavirus in patients with encephalitis, Sri Lanka, 2009-2010

We identified human bocavirus (HBoV) DNA by PCR in cerebrospinal fluid from adults and children with encephalitis in Sri Lanka. HBoV types 1, 2, and 3 were identified among these cases. Phylogenetic analysis of HBoV1 strain sequences found no subclustering with strains previously identified among encephalitis cases in Bangladesh.

Human bocavirus in children with acute respiratory infections in Vietnam

Acute respiratory infections are the major cause of morbidity and mortality globally. Human bocavirus (HBoV), a novel virus, is recognized to increasingly associate with previously unknown etiology respiratory infections in young children. In this study, the epidemiological, clinical, and molecular characteristics of HBoV infections were described in hospitalized Vietnamese pediatric patients. From April 2010 to May 2011, 1,082 nasopharyngeal swab samples were obtained from patients with acute respiratory infections at the Children's Hospital 2, Ho Chi Minh City, Vietnam. Samples were screened for HBoV by PCR and further molecularly characterized by sequencing. HBoV was found in 78 (7.2%) children. Co‐infection with other viruses was observed in 66.7% of patients infected with HBoV. Children 12–24 months old were the most affected age group. Infections with HBoV were found year‐round, though most cases occurred in the dry season (December–April). HBoV was possible to cause severe diseases as determined by higher rates of hypoxia, pneumonia, and longer hospitalization duration in patients with HBoV infection than in those without (P‐value <0.05). Co‐infection with HBoV did not affect the disease severity. The phylogenetic analysis of partial VP1 gene showed minor variations and all HBoV sequences belonged to species 1 (HBoV1). In conclusion, HBoV1 was circulating in Vietnam and detected frequently in young children during dry season. Acute respiratory infections caused by HBoV1 were severe enough for hospitalization, which implied that HBoV1 may have an important role in acute respiratory infections among children. J. Med. Virol. 86:988–994, 2014. © 2013 Wiley Periodicals, Inc.

Parvovirus infection-induced DNA damage response

Parvoviruses are a group of small DNA viruses with ssDNA genomes flanked by two inverted terminal structures. Due to a limited genetic resource they require host cellular factors and sometimes a helper virus for efficient viral replication. Recent studies have shown that parvoviruses interact with the DNA damage machinery, which has a significant impact on the life cycle of the virus as well as the fate of infected cells. In addition, due to special DNA structures of the viral genomes, parvoviruses are useful tools for the study of the molecular mechanisms underlying viral infection-induced DNA damage response (DDR). This review aims to summarize recent advances in parvovirus-induced DDR, with a focus on the diverse DDR pathways triggered by different parvoviruses and the consequences of DDR on the viral life cycle as well as the fate of infected cells.

Viral infections of the lower respiratory tract

Lower respiratory tract infections (LRTIs) are a global burden to public health and are frequently caused by respiratory viruses. Advances in molecular diagnostic techniques have allowed the identification of previously undetected viral pathogens and have improved our understanding of respiratory virus infections. Here we review the epidemiological and clinical characteristics of recently identified viruses including human metapneumovirus, human coronaviruses NL63 and HKU1, human rhinovirus C, bocavirus, WU and KI polyomaviruses, and parechovirus. The roles of these viruses in LRTIs in children and adults are discussed.

Changing epidemiology of respiratory viral infections in hematopoietic cell transplant recipients and solid organ transplant recipients

PURPOSE OF REVIEW

New respiratory viruses have been discovered in recent years and new molecular diagnostic assays have been developed that improve our understanding of respiratory virus infections. This article will review the changing epidemiology of these viruses after hematopoietic stem cell and solid organ transplantation.

RECENT FINDINGS

Respiratory viruses are frequently detected in transplant recipients. A number of viruses have been newly discovered or emerged in the last decade, including human metapneumovirus, human bocavirus, new human coronaviruses and rhinoviruses, human polyomaviruses, and a new 2009 pandemic strain of influenza A/H1N1. The potential for these viruses to cause lower respiratory tract infections after transplantation varies, and is greatest for human metapneumovirus and H1N1 influenza, but appears to be limited for the other new viruses. Acute and long-term complications in hematopoietic and solid organ transplant recipients are active areas of research.

SUMMARY

Respiratory viral infections are frequently associated with significant morbidity following transplantation and are therefore of great clinical and epidemiologic interest. As new viruses are discovered, and more sensitive diagnostic methods are developed, defining the full impact of emerging respiratory viruses in transplant recipients must be elucidated by well designed clinical studies.

Detection of human bocavirus in hospitalised children

AIM

The objectives of this study are to assess the frequency of human bocavirus (HBoV) infection in hospitalised children and to study the clinical symptoms associated with the detection of HBoV.

METHODS

Two groups of hospitalised children were included in this study: group 1 consisted of 1946 children hospitalised from 1st September 2004 to 30th May 2005, and group 2 consisted of 448 children hospitalised from 1st November 2003 to 30th March 2004. The respiratory specimens were tested by polymerase chain reaction.

RESULTS

In the first group, HBoV was detected by polymerise chain reaction in 11/828 (1.3%) of nasal specimens that tested negative for other respiratory viruses. One child tested positive for HBoV in both a nasal aspirate and stool sample. In the second group, nasal specimens were tested for all respiratory viruses, including HBoV. The presence of HBoV infection was detected in seven children (1.6%). Detection of a mixed viral population was observed in four of these children. The main symptoms in children infected with HBoV were rhinitis (50%), cough (45%), dyspnoea (28%), wheezing (28%), fever (23%) and diarrhoea (22%). The final clinical diagnoses were bronchiolitis (seven children), rhinopharyngitis (five children), the exacerbation of asthma (two children) and pneumonia (one child). Moreover, four children have associated gastroenteritis.

CONCLUSION

These results contribute to the interest in the HBoV detection in children. HBoV detection in hospitalised children with or without any other respiratory virus detection was essentially associated with lower respiratory tract infection and in a lower score with upper respiratory tract infection and gastroenteritis.

Infections respiratoires virales émergentes

Viral respiratory infections are very frequent diseases with variable degrees of severity. During the past few years, new respiratory viruses have been discovered by means of molecular biology techniques. In fact, these so far unidentified viruses have been present in humans for a long time but remained unidentified. These viruses are mainly represented by the human metapneumovirus (HMPV), the coronaviruses HCoV-NL63, HCoV-NH and HCoVHKU1, the human bocavirus (HBoV), and the newly described human polyomaviruses WU and KI. Beside these newly identified viruses, new respiratory viruses have emerged in humans within the last years. These viruses have been introduced from animal reservoirs and they generally present a high degree of pathogenicity with high level of mortality in humans. These emerging respiratory viruses are represented by the henipaviruses (Hendra and Nipah viruses), the New World hantaviruses associated with the Hantavirus Pulmonary Syndrome, the coronavirus responsible for the Severe Acute Respiratory Syndrome (SARS-CoV), and the avian influenza virus H5N1. This latter constitutes a major threat, with the risk of a murderous pandemic offering some parallels with the 1918-1919 Spanish flu which caused 20-50 millions deaths worldwide.

[Human bocavirus infections in Spanish 0-14 year-old: clinical and epidemiological characteristics of an emerging respiratory virus]

INTRODUCTION

In 2005 a new respiratory virus, called human bocavirus (HBoV), was cloned from respiratory samples from Swedish infants and children with lower respiratory tract infections.

OBJECTIVES

To determine whether HBoV has circulated in Spain, estimate the frequency of HBoV infections in patients hospitalized for respiratory infection and describe the clinical and epidemiological characteristics of these patients.

PATIENTS AND METHODS

We performed a descriptive prospective study of confirmed HBoV infections in patients aged < 14 years old, hospitalized for respiratory infections between October 2004 and June 2005. Virologic diagnosis was based on multiple RT-PCR for respiratory syncytial virus (RSV) A and B, influenza A,B, and C, parainfluenza 1-4, adenovirus and rhinovirus; PCR was used for human metapneumovirus (hMPV) and PCR in nasopharyngeal aspirates was used for HBoV. The clinical and epidemiological characteristics of patients were analyzed.

RESULTS

Fifty-two cases of HBoV infection were detected, representing 17.1% (95% CI: 13% a 21%) of patients hospitalized for respiratory infections. HBoV was the third most frequent viral agent after RSV (30%) and rhinovirus (25%). In 39 patients (71.1%) coinfection with another respiratory virus was detected. Fifty percent of the patients were aged less than 13.6 months and 75% were aged less than 2 years. The most frequent diagnoses were recurrent wheezing (55.8%), bronchiolitis (21.2%) and pneumonia (15.4%). Clinical sepsis with petechial exanthema was found in two patients. Fever > 38 degrees C was found in 72.1% and radiological infiltrate in 44%. Hypoxia was present in 55.8 % of the patients. HBoV was isolated in distinct episodes in two patients. Coinfections were similar to simple infections except that hypoxia was more frequent in the former (p = 0.038).

CONCLUSIONS

HBoV is one of the most frequent viruses in severe respiratory infections in patients aged less than 14 years old. Only RSV and rhinovirus are more frequent. Coinfections are highly frequent. Most patients are infants with recurrent wheezing and bronchiolitis.