Clinical and molecular epidemiology of human bocavirus in respiratory and fecal samples from children in Hong Kong

BACKGROUND: Human bocavirus (HBoV) is a recently discovered parvovirus associated with respiratory tract infections in children. We conducted the first systematic prospective clinical and molecular study using nasopharyngeal aspirates (NPAs) and fecal samples. METHODS: NPAs negative for influenza virus, parainfluenza virus, respiratory syncytial virus, adenovirus, and coronavirus and fecal samples from patients with acute gastroenteritis were included. On the basis of results from a pilot study using 400 NPAs from all age groups, a prospective 12-month study was conducted to detect HBoV in 1,200 NPAs and 1,435 fecal samples from patients <18 years old by polymerase chain reaction. The complete genome sequences of HBoVs from 12 NPAs and 12 fecal samples were determined. RESULTS: Of the 400 NPAs collected in the pilot study, 20 (5.0%) were found to contain HBoV, all from children <5 years old. In the subsequent prospective study of pediatric patients, HBoV was detected in 83 (6.9%) of 1,200 NPAs. Upper and lower respiratory tract infections were equally common. HBoV was detected in 30 (2.1%) of 1,435 fecal samples. Fever and watery diarrhea were the most common symptoms. The seasonality of HBoV in NPAs and fecal samples was similar. Codetection with other pathogens occurred in 33% and 56% of NPAs and fecal samples, respectively, from patients with HBoV infection. Genomes of HBoVs from NPAs and fecal samples displayed minimal sequence variations. CONCLUSIONS: HBoV was detected in fecal specimens in children with acute gastroenteritis. A single lineage of HBoV was associated with both respiratory tract and enteric infections.     

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.     

广东地区急性呼吸道感染儿童人类博卡病毒的流行状况

目的 了解广东地区急性呼吸道感染患儿人类博卡病毒(HBoV)的感染情况.方法 收集广东地区2007年6月至2008年5月期间呼吸道感染患儿的鼻咽分泌物447份,采用PCR法检测HBoV衣壳蛋白(VP)基因片段,阳性标本作核酸序列测定,并与基冈库中的已知序列进行序列比对和系统进化树分析.结果 447例呼吸道感染患儿标本中HBoV阳件率为5.1%.其中10例患儿与其他病毒混合感染,占阳性标本的43.5%.阳件患儿的主要临床诊断为喘息性肺炎、毛细支气管炎和支气管肺炎,年龄分布从42 d到6岁,主要集中在1岁以内,HBoV感染的季节分布偏向夏、秋及晚春.经序列比对和进化树分析.阳性株的VP基因片段与瑞典株ST1的核酸及氨基酸序列同源性分别为97.8%～98.8%及99.3%～100.0%.结论 HBoV是广东地区儿童下呼吸道感染的重要病原之一,且在1岁以内患儿中高发.该地区HBoV流行株的VP基因片段较为保守,但也存在导致氨基酸改变的突变株.     

Human bocavirus infection in young children in the United States: molecular epidemiological profile and clinical characteristics of a newly emerging respiratory virus

BACKGROUND: Human bocavirus (HBoV) is a newly identified human parvovirus that was originally identified in the respiratory secretions of children with respiratory tract disease. To further investigate the epidemiological profile and clinical characteristics of HBoV infection, we screened infants and children <2 years of age (hereafter referred to as "children") for HBoV. METHODS: Children for whom respiratory specimens submitted to a diagnostic laboratory tested negative for respiratory syncytial virus, parainfluenza viruses (types 1-3), influenza A and B viruses, and adenovirus, as well as asymptomatic children, underwent screening for HBoV by use of polymerase chain reaction (PCR). Respiratory specimens were obtained from the children from 1 January 2004 through 31 December 2004. RESULTS: Twenty-two (5.2%) of the 425 children who had a respiratory specimen submitted to the diagnostic laboratory and 0 of the 96 asymptomatic children were found to be positive for HBoV by PCR (P=.02). Fever, rhinorrhea, cough, and wheezing were observed in > or =50% of the HBoV-positive children. Of the 17 children who had chest radiography performed, 12 (70.6%) had abnormal findings. HBoV appeared to have a seasonal distribution. Nucleotide polymorphisms were detected in the viral capsid protein (VP) 1/VP2 genes. Two distinct HBoV genotypes circulated during the study period. CONCLUSIONS: HBoV is circulating in the United States and is associated with both upper and lower respiratory tract disease in infants and young children.     

Human bocavirus: Current knowledge and future challenges

Human bocavirus(HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool samples, from patients with gastroenteritis. Since then, other viruses related to the first HBoV isolate(HBoV 1), namely HBoV 2, HBoV 3 and HBoV 4, have been detected principally in human faeces. HBo Vs are small nonenveloped single-stranded DNA viruses of about 5300 nucleotides, consisting of three open reading frames encoding the first two the non-structural protein 1(NS1) and nuclear phosphoprotein(NP1) and the third the viral capsid proteins 1 and 2(VP1 and VP2). HBoV pathogenicity remains to be fully clarified mainly due to the lack of animal models for the difficulties in replicating the virus in in vitro cell cultures, and the fact that HBo V infection is frequently accompanied by at least another viral and/or bacterial respiratory and/or gastroenteric pathogen infection. Current diagnostic methods to support HBoV detection include polymerase chain reaction, real-time PCR, enzymelinked immunosorbent assay and enzyme immunoassay using recombinant VP2 or virus-like particle capsid proteins, although sequence-independent amplification techniques combined with next-generation sequencing platforms promise rapid and simultaneous detection of the pathogens in the future. This review presents the current knowledge on HBoV genotypes with emphasis on taxonomy, phylogenetic relationship and genomic analysis, biology, epidemiology, pathogenesis and diagnostic methods. The emerging discussion on HBoV s as true pathogen or innocent bystander is also emphasized.     

Epidemiological profile and clinical associations of human bocavirus and other human parvoviruses

BACKGROUND: Human bocavirus (HBoV) and PARV4 are newly discovered human parvoviruses. HBoV, which was first detected in respiratory samples, has a potential role in the development of human respiratory disease. The present study compared the frequencies, epidemiological profiles, and clinical backgrounds of HBoV and PARV4 infections with those of other respiratory virus infections, by evaluating diagnostic samples referred to the Specialist Virology Laboratory (SVL) at the Royal Infirmary of Edinburgh (Edinburgh, United Kingdom). METHODS: Anonymized samples and study subject information were obtained from the respiratory sample archive of the SVL. Samples were screened for HBoV, PARV4, B19, respiratory syncytial virus (RSV), adenoviruses, influenza viruses, and parainfluenza viruses by use of nested polymerase chain reaction. RESULTS: HBoV infection was detected in 47 (8.2%) of 574 study subjects, ranking third in prevalence behind RSV infection (15.7%) and adenovirus infection (10.3%). Peak incidences of HBoV were noted among infants and young children (age, 6-24 months) during the midwinter months (December and January) and were specifically associated with lower respiratory tract infections. HBoV infections were frequently accompanied by other respiratory viruses (frequency, 43%), and they were more prevalent among individuals infected with other respiratory viruses (17%), frequently adenovirus or RSV. All respiratory samples were negative for PARV4. CONCLUSIONS: In the present study, HBoV was a frequently detected, potential respiratory pathogen, with a prevalence and an epidemiological profile comparable to those of RSV. Identification of HBoV infections may be clinically important in the future.     

人博卡病毒全基因组序列测定与种系分析

目的了解福州地区人博卡病毒(HBoV)在儿童呼吸道感染中的检出情况,并对其进行全基因组序列测定和种系分析。方法收集2007年11月至2008年10月在福建省妇幼保健院因下呼吸道感染住院的重症监护病房的57例小儿鼻咽抽取物标本,用一对特异引物通过PCR扩增法对HBoV基因片段进行检测,对检测出的2例HBoV(FZ1和FZ40)用7对全序列引物进行扩增和拼接,获得这两株病毒全基因组序列,上传GenBank并与基因库中国内外其它10株HBoV的全基因组序列和各氨基酸序列进行比对,并做种系分析。结果FZ1株基因组序列全长为5299bp,与HBoV参考株st2株序列长度相同;而FZ40株的基因组序列全长少2bp。病毒全基因组编码4种蛋白,分别是非结构蛋白NS1、核蛋白NP-1和衣壳蛋白VP1、VP2。结论种系分析显示福州的FZ40株与浙江温岭的WLL-1株关系较近,而FZ1株与北京的两株及泰国的CU6株关系较近。     

Identification of Human Bocavirus type 4 in a child asymptomatic for respiratory tract infection and acute gastroenteritis – Goiânia,Goiás,Brazil

Human Bocavirus (HBoV) has been identified from feces and respiratory samples from cases of both acute gastroenteritis and respiratory illness as well as in asymptomatic individuals.The aim of this study was to detect and characterize HBoV from fecal samples collected from hospitalized children aged less than five years old with no symptoms of respiratory tract infection (RTI) or acute gastroenteritis (AGE). The study involved 119 children and one fecal sample was collected from each participant between 2014 and 2015. HBoV was detected using Nested-PCR, and the viral type identified by genomic sequencing. HBoV-4 was identified from one sample obtained from a hospitalized child with soft tissue tumor of the submandibular region. This is the first report of HBoV-4 identification in Brazil, but we consider that this type may be circulating in the country similar to the other types and new investigations are necessary.     

广东地区首例人博卡病毒的检出及鉴定

目的 建立人博卡病毒(HBoV)筛查检测平台,了解广东地区支气管肺炎患儿HBoV感染情况.方法 采用PCR技术筛查HBoV核蛋白(NP)基因片段,阳性标本作HBoV衣壳蛋白(VP)基因片段鉴定,并进行核酸序列和进化树分析.结果 从50例住院支气管肺炎患儿鼻咽分泌物中检测出1例HBoV,为广东地区首例,命名为GD-1株.HBoV VP基因部分序列分析与基因库中HBov VP基因序列同源性比对,除与韩国KNIH-2K6GJ2713株同源性为36%、与美国NH4549株同源性为77%外,与其他所有VP基因序列同源性均>95%,与法国株、北京株、加拿大株的同源性>98%.GD-1株HBoV部分VP基因片段与北京CZ株、加拿大株、西班牙株、意大利株等在同一基因进化簇主分枝中,与法国175/03/2002FRA株同在一个侧枝中.结论 广东地区存在HBoV感染,有进一步研究的必要性.     

Human bocavirus amongst an all‐ages population hospitalised with acute lower respiratory infections in Cambodia

Please cite this paper as: Arnott et al. (2013) Human bocavirus amongst an all‐ages population hospitalised with acute lower respiratory infections in Cambodia. Influenza and Other Respiratory Viruses 7(2) 201–210. Background Human bocavirus (HBoV) is a novel parvovirus that is associated with respiratory and gastrointestinal tract disease. Objectives To investigate the prevalence and genetic diversity of HBoV amongst hospitalized patients with acute lower respiratory infection (ALRI) in Cambodia. Study Design Samples were collected from 2773 patients of all ages hospitalised with symptoms of ALRI between 2007 and 2009. All samples were screened by multiplex RT‐PCR/PCR for 18 respiratory viruses. All samples positive for HBoV were sequenced and included in this study. Results Of the samples tested, 43 (1·5%) were positive for HBoV. The incidence of HBoV did not vary between the consecutive seasons investigated, and HBoV infections were detected year‐round. The incidence of HBoV infection was highest in patients aged <2 years, with pneumonia or bronchopneumonia the most common clinical diagnosis, regardless of age. A total of 19 patients (44%) were co‐infected with HBoV and an additional respiratory pathogen. All isolates were classified as HBoV type 1 (HBoV‐1). High conservation between Cambodian NP1 and V1V2 gene sequences was observed. Conclusions Human bocavirus infection can result in serious illness, however is frequently detected in the context of viral co‐infection. Specific studies are required to further understand the true pathogenesis of HBoV in the context of severe respiratory illness.     

CD4+ T helper cell responses against human bocavirus viral protein 2 viruslike particles in healthy adults

BACKGROUND: Human bocavirus (HBoV) was recently described as a new member of the Parvoviridae family, and its possible association with respiratory illness in infants has been discussed. To date, HBoV genomes have been detected worldwide in respiratory tract samples obtained from children with pulmonary diseases, whereas only limited data on virus-specific immunity are available, mainly because of the lack of recombinant viral antigens. METHODS: HBoV viruslike particles (VLPs) were produced in insect cells and characterized by electron microscopy and cesium chloride gradient centrifugation. HBoV viral protein 2 (VP2)-specific antibodies and CD4+ T helper cell responses were analyzed by enzyme-linked immunosorbent assay and enzyme-linked immunospot assay. RESULTS: VP2 capsid proteins of HBoV were produced in insect cells infected with a recombinant baculovirus, and the formation of icosahedral VLPs (diameter, 21-25 nm; sedimentation density, 1.33 g/cm(3)) was demonstrated. A significant increase in secretion of VP2-specific interferon-gamma was detected in cultures of peripheral blood mononuclear cells obtained from 69 healthy adults found to be positive for HBoV-specific immunoglobulin G antibodies, compared with control stimulations. In parallel, T cell responses against identically expressed parvovirus B19 VP2 VLPs were frequently observed in the individuals studied, without there being obvious cross-reactions between HBoV and parvovirus B19. CONCLUSIONS: Data suggest the presence of HBoV-specific immune responses in adults and strongly support a high prevalence of HBoV among humans.     

Human bocavirus and human metapneumovirus in hospitalized children with lower respiratory tract illness in Changsha,China

Background

Lower respiratory tract illness is a major cause of morbidity and mortality in children worldwide, however, information about the epidemiological and clinical characteristics of LRTIs caused by HMPV and HBoV in China is limited.

Objectives

Human bocavirus (HBoV) and human metapneumovirus (HMPV) are two important viruses for children with lower respiratory tract infections (LRTI). We aimed to assay the correlation between viral load and clinical characteristics of HBoV and HMPV with LRTI in Changsha, China.

Methods

Nasopharyngeal aspirates (NPAs) from children with LRTI were collected. Real‐time PCR was used to screen HBoV and HMPV. Analyses were performed using SPSS 16.0 software.

Results

Pneumonia was the most frequent diagnosis. There was no significant difference between HBoV‐ and HMPV‐positive patients in age (P = .506) or hospitalization duration (P = .280); 24.1% and 18.2% were positive for HBoV and HMPV. HBoV infections peaked in summer (32.2%), and HMPV infections peaked in winter (28.9%). The HBoV‐positive patients had a shorter hospitalization duration than the HBoV‐negative patients (P = .021), and the HMPV‐positive patients had a higher prevalence of fever than the HMPV‐negative patients (P = .002). The HBoV viral load was significantly higher among patients aged <1 year (P = .006). The mean HBoV and HMPV viral loads were not significantly different between patients with single infections and coinfections. Patients infected with HBoV only were older than those coinfected with HBoV and other respiratory viruses (P = .005). No significant difference was found in the clinical characteristics of patients infected with HMPV only and those coinfected with HMPV and other respiratory viruses.

Conclusion

Pneumonia was the most frequent diagnosis caused by HBoV and HMPV. Neither HBoV nor HMPV viral load was correlated with disease severity.     

High prevalence of human bocavirus 1 in infants with lower acute respiratory tract disease in Argentina, 2007-2009

Human bocavirus (HBoV) is a parvovirus whose association with respiratory disease is currently under investigation.ObjectiveTo determine HBoV prevalence in children with lower acute respiratory infection.MethodsWe investigated HBoV in 433 nasopharyngeal aspirates collected in 2007–2009 from children 0 to 5 years old hospitalized with bronchiolitis or pneumonia in Córdoba, Argentina.ResultsThe general prevalence of HBoV was 21.5% and the positive cases (HBoV+) were more frequent during winter and spring. The mean age of HBoV+ patients was 6.9 months, with 87.1% of the detections corresponding to infants less than 1 year old (among which the prevalence of HBoV was 26.3% in patients < 3 months of age, 22.1% in 3 to 6 months, 25.3% in 6 to 9 months, and 18.8% in 9 to 12 months). The sequence analysis of the NP1 coding region of 15 isolates showed that all isolates from Cordoba were HBoV1 which exhibited a homology of nearly 100% both among themselves and with the originally discovered virus from 2005.ConclusionOverall, our results indicate that HBoV is a significant pathogen that contributes to acute respiratory infection both on its own and during coinfection with other viruses.     

Human bocavirus infection in hospitalized children in Italy

Background Human bocavirus (HBoV) was first discovered in Sweden in 2005 and has now been found worldwide; however its role in clinically relevant diseases has not yet been clearly defined. Objectives To gain new insight into HBoV infection among children hospitalized with acute respiratory infections in Rome. Methods Between November 2004 and May 2007, 415 nasal washings were tested for the presence of an extensive range of respiratory viruses using molecular methods. Results Viral pathogens were detected in 214 children (51·6%), 28·9% being respiratory syncytial virus (RSV) and 9·6% being rhinovirus positive. Of the 34 children (8·2%) who tested positive for HBoV, 21 (61·8%) were co‐infected with another respiratory virus, mainly RSV. Human bocavirus was the only pathogen identified in four pneumonia and six bronchiolitis cases in March 2005 and January 2007, respectively. Human bocavirus was also detected in one child hospitalized with gastroenteritis and in another with erythema. Conclusions In the examined population, HBoV was the third most common virus detected but with a high rate of co‐infection with other respiratory viruses. Human bocavirus appeared to be the etiological agent in some pneumonia and bronchiolitis cases in which tests for all likely respiratory pathogens were negative.     

Serologically diagnosed acute human bocavirus 1 infection in childhood community‐acquired pneumonia

Aim

To assess the role of human bocavirus 1 (HBoV1) as a causative agent of non‐severe community‐acquired pneumonia (CAP) in children.

Methods

Patients aged 2‐59 months with non‐severe CAP (respiratory complaints and radiographic pulmonary infiltrate/consolidation) attending a University Hospital in Salvador, Brazil were enrolled in a prospective cohort. From 820 recruited children in a clinical trial ( ClinicalTrials.gov NCT01200706), nasopharyngeal aspirate (NPA), and acute and convalescent serum samples were obtained from 759 (92.6%) patients. NPAs were tested for 16 respiratory viruses by PCR. Acute HBoV1 infection was confirmed by measuring specific IgM and IgG responses in paired serum samples.

Results

Respiratory viruses were detected in 693 (91.3%; 95%CI: 89.1‐93.2) CAP cases by PCR. HBoV1‐DNA was detected in 159 (20.9%; 95%CI: 18.2‐24.0) cases. Of these 159 PCR positive cases, acute HBoV1 infection was confirmed serologically in 38 cases (23.9%; 95%CI: 17.8‐31.0). Overall, acute HBoV1 infection was confirmed in 5.0% (38/759) of non‐severe CAP patients. HBoV1 was detected in 151 cases with at least one other virus making 31.7% of all multiple virus (n = 477) detections. Among all 759 cases, 216 had one respiratory virus detected, and sole HBoV1 was detected in only 8 (3.7%). Acute HBoV1 infection was serologically diagnosed in 34 (22.5%) HBoV1‐DNA‐positive cases with another virus, compared to 4 (50.0%) cases with sole virus detection (p = 0.09).

Conclusion

HBoV1 was detected by PCR in one fifth of the children with non‐severe CAP and acute HBoV1 infection was serologically confirmed in one quarter of these cases.

     

人博卡病毒感染的流行病学和诊断研究

人博卡病毒属于细小病毒科（Parvoviridae）博卡病毒属（Bocavirus）。2005年,瑞典学者Allande首次从患急性呼吸道感染的婴幼儿中分离得到该病毒。全球已有人博卡病毒感染的报道,但对该病毒仍然知之甚少。本文对人博卡病毒感染的流行病学特点和诊断作一综述。     

Frequency of human bocavirus (HBoV) infection among children with febrile respiratory symptoms in Argentina, Nicaragua and Peru

Please cite this paper as: Salmón‐Mulanovich et al. (2010) Frequency of human bocavirus (HBoV) infection among children with febrile respiratory symptoms in Argentina, Nicaragua and Peru. Influenza and Other Respiratory Viruses 5(1), 1–5. Background Globally, respiratory infections are the primary cause of illness in developing countries, specifically among children; however, an etiological agent for many of these illnesses is rarely identified. Objectives Our study aimed to estimate the frequency of human bocavirus (HBoV) infection among pediatric populations in Argentina, Nicaragua and Peru. Methods We conducted a cross‐sectional study using stored samples of an influenza‐like illness surveillance program. Irrespective of previous diagnosis, nasopharyngeal or nasal swab specimens were randomly selected and tested using real‐time PCR from three sites during 2007 from patients younger than 6 years old. Results A total of 568 specimens from Argentina (185), Nicaragua (192) and Peru (191) were tested. The prevalence of HBoV was 10·8% (95% CI: 6·3; 15·3) in Argentina, 33·3% in Nicaragua (95% CI: 26·6; 40·1) and 25·1% in Peru (95% CI: 18·9; 31·3). Conclusions These findings demonstrate circulation of HBoV in Argentina, Nicaragua and Peru among children with influenza‐like symptoms enrolled in a sentinel surveillance program.     

Human bocavirus infection in a neonatal intensive care unit

Human bocavirus (HBoV) plays a non-insignificant role as a pathogen in respiratory tract diseases in the pediatric population, especially in infants younger than 2 years of age. In this paper, we have described two cases of a possible nosocomial infection in a neonatal intensive care unit being HBoV the sole detected respiratory virus in clinical samples.     

Human bocavirus: a novel parvovirus epidemiologically associated with pneumonia requiring hospitalization in Thailand

BACKGROUND: We detected human bocavirus (HBoV) infection in 4.5% of hospitalized patients with pneumonia in rural Thailand. However, the role of HBoV as a pathogen is unclear. METHODS: We compared HBoV infection in patients with pneumonia with that in asymptomatic control patients enrolled between 1 September 2004 and 31 August 2005 in the same hospitals in Thailand. We examined outpatients with influenza-like illness for HBoV infection and tested for 13 additional respiratory viruses. Epidemiologic and clinical characteristics of HBoV infection are described. RESULTS: HBoV infection was detected in 20 (3.9%) of 512 outpatients and 3 (1%) of 280 control patients. Coinfection with other viruses was detected in 83% of patients with pneumonia and in 90% of outpatients. Compared with control patients, HBoV infection was significantly associated with pneumonia requiring hospitalization (adjusted odds ratio, 3.56 [95% confidence interval, 1.06-11.91]; P=.04). Eighty-three percent of HBoV infections were detected in patients with pneumonia who were <5 years old. More patients with pneumonia associated with HBoV-respiratory syncytial virus (RSV) or human parainfluenza virus (HPIV) coinfections had wheezing than patients with RSV and HPIV infections alone (9 [53%] of 17 vs. 32 [23%] of 138]; P=.01). CONCLUSIONS: HBoV infection was epidemiologically associated with pneumonia among young children in rural Thailand, but infection and illness may be dependent on coinfection with other viruses.     

High prevalence of antibodies against polyomavirus WU,polyomavirus KI,and human bocavirus in German blood donors

Background  

DNA of the polyomaviruses WU (WUPyV) and KI (KIPyV) and of human bocavirus (HBoV) has been detected with varying frequency in respiratory tract samples of children. However, only little is known about the humoral immune response against these viruses. Our aim was to establish virus-specific serological assays and to determine the prevalence of immunoglobulin G (IgG) against these three viruses in the general population.