Human Bocavirus in Korean Children with Gastroenteritis and Respiratory Tract Infections

Human bocavirus in Saudi Arabia: Molecular epidemiology and Co-infections among children with acute respiratory tract infections during 2014-2016

Respiratory tract infections due to a variety of viruses continue to threaten the human population worldwide, particularly in developing countries. Among the responsible viruses, Human Bocavirus (HBoV), a novel discovered virus, causes respiratory tract and gastroenteritis disorders in young children. In Saudi Arabia, data regarding virus molecular epidemiology and evolution and its implication in respiratory tract infection are scarce. In the current study, genetic diversity and circulation pattern of HBoV-1 among hospitalized children due to acute respiratory tract infection (ARTI) during two consecutive years were charted. We found that 3.44% (2014/2015) and 11.25% (2015/2016) of children hospitalized due to ARTI were infected by HBoV-1. We have shown that HBoV was detected year-round without a marked seasonal peak. HBoV-1 also was co-detected with one or multiple other respiratory viruses. The multisequence analysis showed high sequence identity (∼99%) (few point mutation sites) between strains of each genotype and high sequence variation (∼79%) between HBoV-1 and the other 3 genotypes. Phylogenetic analysis showed the clustering of the study's isolates in the HBoV-1 subclade. Our data reveal that genetically conserved HBoV-1 was circulating among admitted children during the course of the study. Further epidemiological and molecular characterization of multiple HBoV-1 strains for different years and from all regions of Saudi Arabia are required to understand and monitor the virus evolution.

Human Bocavirus in children with acute gastroenteritis in Piedmont, Italy

BACKGROUND

Gastroenteritis is a common disease in children, characterized by diarrhea, vomiting, abdominal pain, and fever. Co-detection of human Bocavirus (HBoV) with other gastroenteric viruses was reported a lot in patients with acute gastroenteritis.

METHODS

This paper presents the real-time RT-PCR Taqman assay for the detection and quantification of HBoV for clinical fecal samples collected from hospitalized children with acute gastroenteritis in Piedmont.

RESULTS

All fecal specimens were tested for the presence of HBoV with specific primers and probe. A total of 17 out of 123 (13.92%) episodes of acute gastroenteritis were associated with HBoV genomic detection with median viral load 6864.75±19784.79 genomes/mg fecal specimens. Among the 17 HBoV-positive cases, 11 were also positive for other viral pathogens, including Rotavirus (N.=2), astrovirus (N.=1), norovirus GII (N.=6), norovirus GI (N.=2). Two cases were positive for more than one virus including norovirus GII and norovirus GI (N.=1) and Rotavirus, sapovirus and astrovirus (N.=1). A higher detection of HBoV infections was observed in winter, and peaking in February.

CONCLUSIONS

Although HBoV is suspected to be responsible for gastroenteritis in children, our data showed that this association was uncertain since no difference was observed in term of viral load in the group with single infection of HBoV and group of coinfections with other viral agent.

Occurrence of Human Enteric Viruses in Water Sources and Shellfish: A Focus on Africa

Enteric viruses are a diverse group of human pathogens which are primarily transmitted by the faecal-oral route and are a major cause of non-bacterial diarrhoeal disease in both developed and developing countries. Because they are shed in high numbers by infected individuals and can persist for a long time in the environment, they pose a serious threat to human health globally. Enteric viruses end up in the environment mainly through discharge or leakage of raw or inadequately treated sewage into water sources such as springs, rivers, dams, or marine estuaries. Human exposure then follows when contaminated water is used for drinking, cooking, or recreation and, importantly, when filter-feeding bivalve shellfish are consumed. The human health hazard posed by enteric viruses is particularly serious in Africa where rapid urbanisation in a relatively short period of time has led to the expansion of informal settlements with poor sanitation and failing or non-existent wastewater treatment infrastructure, and where rural communities with limited or no access to municipal water are dependent on nearby open water sources for their subsistence. The role of sewage-contaminated water and bivalve shellfish as vehicles for transmission of enteric viruses is well documented but, to our knowledge, has not been comprehensively reviewed in the African context. Here we provide an overview of enteric viruses and then review the growing body of research where these viruses have been detected in association with sewage-contaminated water or food in several African countries. These studies highlight the need for more research into the prevalence, molecular epidemiology and circulation of these viruses in Africa, as well as for development and application of innovative wastewater treatment approaches to reduce environmental pollution and its impact on human health on the continent.

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.

The First Detection of Human Bocavirus Species 2 and 3 in Raw Sewage and Mussels in South Africa

Human bocavirus (HBoV) has a global distribution and is associated with respiratory and enteric infections, particularly in the paediatric population. In this study, raw sewage and mussel samples were analysed for the presence of HBoV using nested PCR with primers targeting the VP1/VP2 junction. Amplification and sequencing of the 382 bp region followed by phylogenetic analysis indicated the presence of HBoV 2 in mussel samples and HBoV 3 in sewage samples. This is the first report describing the presence of enteric-associated HBoV in environmental samples from South Africa and in mussel samples from the African continent. The results signify the need for further studies examining the potential risk of foodborne transmission of HBoV and highlight the importance of continued screening to determine the prevalence and epidemiology of HBoV in South Africa.

Human bocavirus infections and co-infections with respiratory syncytial virus and Rotavirus in children with acute respiratory or gastrointestinal disease

The objective of this study was to determine the frequency and seasonal distributions of HBoV detections among Iranian children presenting with acute respiratory or gastrointestinal symptoms and to compare infections among children with concomitant respiratory syncytial virus (RSV) and rotavirus (RV) infections. A cross-sectional study at Mofid Children's Hospital in Tehran, Iran, enrolled children < 3 years old presenting with either acute respiratory or gastrointestinal symptoms during the period of 2017-2018. Respiratory or stool specimens collected from each group were initially tested by RT-PCR assays for RSV and RV, respectively, and all specimens were tested for HBoV by PCR assay. Clinical and demographic data were collected and statistically compared. Five hundred respiratory and stool specimens each were tested and 67 (13.4%) and 72 (14.4%) were PCR positive for HBoV, respectively. Of 128 (25.6%) respiratory specimens positive for RSV, 65% were also positive for HBoV (p = 0.019); of 169 (33.8%) stool specimens positive for RV, 62.5% were also positive for HBoV (p = 0.023). Peak circulation of all viruses was during late winter and early spring months (Jan-Mar) in gastrointestinal infections and during winter (Feb-Jan) in respiratory infections. HBoV is commonly detected among Iranian children presenting with acute respiratory or gastrointestinal symptoms and is often present as co-infections with RSV and RV, respectively.

Phylogenetic analysis of human bocavirus in children with acute respiratory infections in Iran

Human bocavirus (HBoV) was first characterized in nasopharyngeal aspirates from young children with acute respiratory infections. It is prevalent among children with acute wheezing. This study was carried out in order to analyze the infection frequency and coinfection rates of HBoV with respiratory syncytial virus (RSV) and to perform phylogenetic analysis of HBoV in samples of children with acute respiratory infection in Isfahan, Iran. During the time period 2016-2017, altogether 75 respiratory samples from children hospitalized with acute respiratory infection were collected. The samples were first screened for RSV by direct immunofluorescence method and then subjected to detect HBoV DNA by PCR. Genotyping of HBoV-positive samples was conducted by direct sequencing of PCR products using NP and VP1/VP2 genes. Out of 75 respiratory samples, 20 (26.7%) and 10 (13.3%) were positive for RSV and HBoV, respectively. The coinfection rate was 40% (p = 0.048). Considering the seasonal distribution, winter has the highest extent outbreak (p = 0.036). Sequence analysis of positive samples exhibits that all of the isolated HBoV were related to genotype 1 (HBoV-1) with minimal sequence variations. Increasing frequency of HBoV suggests that the virus is related to acute respiratory infection in children. A single genetic lineage of HBoV1 seems to be the major genotype in Iran.

Detection of human bocavirus-1 in both nasal and stool specimens from children under 5 years old with influenza-like illnesses or diarrhea in Gabon

Objective

Human bocavirus (HBoV) is a viral pathogen which causes respiratory tract diseases and acute gastroenteritis worldwide. This virus mainly affected children under 5 years old. There is little information on HBoV in Gabon. Two first studies was conducted to determine the prevalence of respiratory and enteric viruses in children under 5 years old who visited health centers for influenza-like illness (ILI) or diarrhea in Gabon from March 2010 to June 2011. However, HBoV was not included in the screening. The aim of this retrospective study was to evaluate the prevalence and the HBoV genotype in children under 5 years old with ILI or diarrhea in Gabon.

Results

A total of 810 nasal swabs and 317 feces samples collected during the two first study were analyzed among which 32 (4.4%) and 7 (2.2%) were positive for HBoV respectively. While there were no significant differences in prevalence between age groups in children with ILI, all children with diarrhea were under 12 months of age. Moreover, 84.4 and 42.8% were diagnosed in co-infections with at least one other respiratory virus, or enteric viruses respectively. Finally, HBoV subtype 1 has been detected in both respiratory and gastrointestinal tracts with very low variability.

Human bocavirus in hospitalized children under 5 years with acute respiratory infection, São Paulo, Brazil, 2010

The aims of this study were to investigate the human bocavirus (HBoV) frequency and genotypes in hospitalized children <5 years presenting acute respiratory infections (ARI) within the São Paulo metropolitan area. Nasopharyngeal samples from 300 patients, previously screened for common respiratory viruses, were tested by qPCR for the NSP1 and NP-1 genes. The VP1/2 gene in positive samples was then amplified by PCR and sequenced. A total of 49 positive HBoV cases (16.3%; mean Ct value of 34.41) were detected with the mean age being 18.1 months (range 1 month to 5 years) and the median age being 1 year of age. Children aged between 0 and 12 months had higher detection rates of HBoV (69.4%; 34/49; mean Ct = 34.45) than children from other age groups (30.6%; 15/49; mean Ct = 34.34). No significant differences were observed between HBoV Ct levels and clinical illness. The occurrence was more frequently associated with fall (38.8%; 19/49) and spring (36.7%; 18/49). All 12 sequenced isolates were identified as HBoV-1, displaying minor genetic variation compared to the Swedish reference strains ST1 and ST2 (99.1–99.7% nt). The sole identification of HBoV-1 supports the hypothesis that this particular genotype is strongly related to ARI, and contributes to the role of this virus in the aetiology of respiratory diseases.