Phylogenetic analysis of human bocavirus isolated from children with acute respiratory illnesses and gastroenteritis in Iran

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.

Detection of Human Boca Virus in Gastric Adenocarcinoma

Background: Gastric cancer is one of the most common cancers worldwide. Human bocavirus (HBoV), a recently isolated virus, has been investigated for its role in many respiratory and enteric diseases. Few studies have reported its presence in solid tumors, such as lung and colon cancers. The aim of this study was to detect the presence of the HBoV1 genome in gastric adenocarcinoma, which has not yet been evaluated. Methods: Formalin-fixed paraffin-embedded (FFPE) blocks of 189 gastric tumors and 50 blocks of non-tumor gastric tissue products from elective weight reduction operations were collected. DNA extraction and real-time polymerase chain reaction (PCR) were performed for HBoV1 detection. DNA sequencing was performed using ABI Genetic Analyzer series 3500. Results: The mean age of the patients was 60±13.33 years. Tumors were more common in males than females (2.5/1). HBoV1 PCR was positive in 34 (18%) cases of GC and 10 (20%) cases of chronic gastritis (P>0.05). There was no association between age, sex, stage, and histologic subtype of the tumor and HBoV1 positivity (P>0.05) in tumor samples. The rate of intestinal metaplasia and presence of lymphoid stroma were also not more frequent in HBoV1-positive tumors (P>0.05). Conclusion: The HBoV1 can be detected in a relatively high proportion of Iranian patients with gastric cancer (18%) with no predilection for specific subtypes and no association with the degree of lymphocytic infiltration. HBoV1 can also be observed in approximately 20% of chronic gastritis cases. Further comprehensive studies are needed to elucidate the role of HBoV1 in gastric cancer development.

Epidemiology of Human Bocavirus in the Middle East and North Africa: Systematic Review

The emergence of the COVID-19 pandemic highlighted the importance of studying newly emerging viruses that cause respiratory illnesses. Human bocavirus (HBoV) is one of the relatively newly discovered viruses that has been detected worldwide and causes respiratory and gastrointestinal infections, mainly in pediatric patients. However, little is known about the pathogenicity and evolution of HBoV. This systematic review was initiated to clarify the prevalence and circulating genotypes of HBoV in both respiratory and stool samples from patients of all age groups in the Middle East and North Africa (MENA) from 2005 to February 2021. We performed an electronic search through Science Direct, Scopus, PubMed, Mendeley and Cochrane Library databases. We included all studies reporting the detection rate of HBoV in the MENA region. Data were extracted, and the quality of the included articles was assessed. We included articles containing data on HBoV only or with other respiratory or gastrointestinal viral infections. Review articles, case studies, and animal and environmental studies were excluded. The final number of articles included in this study was 65 articles. The results showed that the HBoV prevalence in children was the lowest in Iran (0%) and the highest in Egypt (56.8%). In adults, the lowest and the highest prevalence were reported in Iran, with values of 0% and 6.6%, respectively. Regarding the respiratory cases, our findings revealed no significant difference between HBoV prevalence among the tested categories (p-value = 0.998). The present study has shown that HBoV is common in children and adults in the MENA region. This systematic review highlights the need for more data on the role of coinfection of HBoV and other viruses, for instance, SARS-CoV-2 in children with acute bronchiolitis.

Prevalence of Respiratory Viral Infections in Children with Asthma in Kermanshah

Background: Asthma is a chronic inflammatory disorder of lung airways, affecting about 300 million people worldwide. Several risk factors are involved in asthma development, such as environmental allergens, genetic susceptibility, and respiratory viral infections. Viral infections induce NF-kB and inflammatory pathways that lead to the production of cytokines, chemokines, and inflammatory proteins and, finally, a reduction of lung volume and function. Objectives: The aim of this study was to evaluate viral infections’ prevalence in children with asthma from 2016 to 2017. Methods: One hundred throat swab samples were collected from asthmatic children. Extraction of RNA and cDNA synthesis were performed to recognize parainfluenza viruses, rhinoviruses, influenza viruses, and respiratory syncytial virus (RSV) using real-time PCR. Also, the associations of age, sex, and other studied factors with asthmatic attacks were evaluated. Results: In this study, 41 viruses were detected, including 21 cases of rhinoviruses (51.22%), 10 cases of parainfluenza (24.39%), seven cases of respiratory syncytial virus (17.07%), and three cases of the influenza virus (7.32%). Regarding seasonal incidence, the prevalence of the viruses was high in autumn and winter, and there was a significant relationship between seasonal incidence and gender. However, there were no statistically significant relationships between the prevalence of the viruses and age or gender. Conclusions: The most important viral causes of childhood asthma in this study were found to be rhinoviruses, followed by parainfluenza. The lowest prevalence was related to the RSV and influenza virus, which the two viruses also showed the lowest seasonal outbreaks. Therefore, it can be said that with an increase in the seasonal incidence of respiratory viruses, the effects of these viruses will be greater on asthma.

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.

The Molecular Detection of Human Bocavirus (HBoV) in Colorectal Tissue with Malignant and Non-Malignant Lesions

Background: Colorectal cancer (CRC) as a worldwide human health concern is identified being a multifactorial subject that infection with specific viral particles such as oncogenic viruses is research interest. Human bocavirus (HBoV) as a recent isolated virus has been investigated in many respiratory and enteric diseases but rare studies evaluates it in tissue specimens especially in cancerous sections. The aim of this study was to detect the presence of HBoV genome and its genotyping in CRC patient’s tissue and compare the result with matched healthy control group tissue. Method: in this retrospective case-control study, CRC cases were sporadic and non-familial cancerous while control subjects had healthy or non-malignant lesions in colon tissue. A conventional-PCR performed by specific primers for HBoV VP1 gene. After sequencing of positive PCR products, raw data used for trimming and alignment by bioinformatics software CLC Main Workbench 5 and MEGA5. SPSS v.22 used for statistical calculations. Result: a total of 157 subjects were participated that 66 were diagnosed as CRC cases and 91 were non-CRC colon tissue as control group that matched by the cases. The mean age (y) ± standard deviation of each case and control groups were 59.35±14.48 and 57.21±14.66, respectively. PCR results showed there were 1.3% (2/157) HBoV positive (of each groups one was positive). Sequencing analysis showed all were HBoV-1 genotype. Conclusion: our study showed there are low rate of HBoV genome in Iranian CRC and non-CRC colon tissue. Furthermore, the predominant genotype in our studied subsets were HBoV-1 according to phylogenetic analysis.

Association of specific viral infections with childhood asthma exacerbations

Introduction

Asthma exacerbations may occur due to a variety of triggers including respiratory viruses. The aim of this study was to determine the role of particular viral infections in asthma exacerbations in children.

Materials and methods

The study was performed at Dr. Daneshvari Hospital Pediatric Emergency Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran between 2014 and 2015. A nasopharyngeal aspirate or swab was obtained from each patient during admission. All samples were maintained at 4 °C until submission to the virology laboratory and were tested for respiratory viruses by nucleic acid testing.

Results

A total of 60 patients with asthma exacerbations were recruited for this study. Of the 60 samples collected from the patients with acute asthma exacerbations, rhinovirus was detected in 12 patients (20%), respiratory syncytial virus in 5 (8%), adenovirus in 5 (8%), and influenza virus in 1 (1.6%). Respiratory pathogens were not detected in 37 (61%) samples. All the samples investigated showed single viral infection.

Conclusions

To conclude, the most common viruses detected were rhinovirus followed by respiratory syncytial virus (RSV) and adenovirus. RSV was more commonly associated with more severe attacks. Both the study design (e.g., time of sampling, age of the patients, etc.) and also the method used for viral detection influence the frequency of detection of the respiratory viruses.

Phylogenic analysis of human bocavirus detected in children with acute respiratory infection in Yaounde, Cameroon

Objective

Human Bocavirus (HBoV) was first identified in 2005 and has been shown to be a common cause of respiratory infections and gastroenteritis in children. In a recent study, we found that 10.7% of children with acute respiratory infections (ARI) were infected by HBoV. Genetic characterization of this virus remains unknown in Central Africa, particularly in Cameroon Leeding us to evaluate the molecular characteristics of HBoV strains in Cameroonian children with ARI.

Results

Phylogenetic analysis of partial HBoV VP1/2 sequences showed a low level of nucleotide variation and the circulation of HBoV genotype 1 (HBoV-1) only. Three clades were obtained, two clustering with each of the reference strains ST1 and ST2, and a third group consisting of only Cameroon strains. By comparing with the Swedish reference sequences, ST1 and ST2, Cameroon sequences showed nucleotide and amino acid similarities of respectively 97.36–100% and 98.35–100%. These results could help improve strategies for monitoring and control of respiratory infections in Cameroon.

Epidemiology of viral gastroenteritis in Iran

Viruses are prominent causative agents of acute gastroenteritis in children <5 years of age per year. In the present review, all viral gastroenteritis studies in Iran were assessed, and the mean prevalences of rotaviruses, noroviruses, enteric adenoviruses, sapoviruses and astroviruses associated with acute gastroenteritis were 39.9%, 6%, 5.7%, 4.2% and 2.7%, respectively. In 2 studies, human bocavirus and human parechovirus were detected in 21.8% and 23.7% of children with acute gastroenteritis, respectively.

Viral load of human bocavirus-1 in stools from children with viral diarrhoea in Paraguay

Since their discovery, four species of human bocavirus (HBoV) have been described in patients with respiratory and gastrointestinal diseases. However, a clear causal association between HBoV-1 and gastroenteritis has not been demonstrated. In this study, we describe the detection and quantification of HBoV-1 in stools from children with acute non-bacterial gastroenteritis using quantitative polymerase chain reaction. HBoV-1 genome was detected in 10.6% of stools with frequent association with rotavirus and norovirus. The median of HBoV-1 viral load was 1.88 × 104 genome/ml, lower than previously shown in secretions of patients with respiratory infections, without any obvious association between high viral load and presence of HBoV as single agent. Thus, although HBoV-1 was frequently detected in these patients, there is no clear causal association of this agent with diarrhoea. Indeed, HBoV-1 DNA in stools of patients with gastroenteritis without respiratory symptoms may be a remnant of previous infections or associated with prolonged shedding of virus in the respiratory or digestive tracts.

Human bocavirus-the first 5 years

Four species of human bocavirus (HBoV) have been recently discovered and classified in the Bocavirus genus (family Parvoviridae, subfamily Parvovirinae). Although detected both in respiratory and stool samples worldwide, HBoV1 is predominantly a respiratory pathogen, whereas HBoV2, HBoV3, and HBoV4 have been found mainly in stool. A variety of signs and symptoms have been described in patients with HBoV infection including rhinitis, pharyngitis, cough, dyspnea, wheezing, pneumonia, acute otitis media, fever, nausea, vomiting, and diarrhea. Many of these potential manifestations have not been systematically explored, and they have been questioned because of high HBoV co-infection rates in symptomatic subjects and high HBoV detection rates in asymptomatic subjects. However, evidence is mounting to show that HBoV1 is an important cause of lower respiratory tract illness. The best currently available diagnostic approaches are quantitative PCR and serology. This concise review summarizes the current clinical knowledge on HBoV species.