Human Bocavirus-infection (HBoV): an important cause of severe viral obstructive bronchitis in children

BACKGROUND: Apart from established pathogens of lower respiratory tract infections, such as respiratory syncytial virus (RSV), an increasing number of additional agents has been identified in recent years. In 2005 the human bocavirus (hBoV) has been isolated from respiratory tract samples and has been reported worldwide with frequencies ranging from 1.5 to 18.3% in respiratory samples from children with airway infections. PATIENTS: We investigated 173 specimens of a total number of 162 children who were inpatients with severe respiratory tract infections most of whom required oxygen therapy. METHOD: We analyzed respiratory tract samples (83% nasopharyngeal washes, 15% tracheal secretions, 2% bronchoalveolar lavages) for adenoviruses, influenza A und B viruses, parainfluenzaviruses types 1 to 3 and RSV using antigen-specific immunofluorescence assays. Additionally we tested human metapneumovirus (hMPV) and hBoV using a PCR assay. MAIN RESULTS: 35.8% specimens were negative in all assays, 54.3% were positive for RSV and 9.8% were positive for adeno-, influenza-, parainfluenzaviruses or hMPV. HBoV could be detected in 17 specimens (9.8%), defining HBoV to be the second most frequent pathogen. Nine of these patients showed a coinfection with RSV, one with parainfluenza virus. Viral loads did range from 2x10 (2) to 5.6x10 (10) genome equivalents/ml with higher viral loads being observed in the first days after disease onset. Most children were infected in the months between December and April. Half of the patients with isolated HBoV infection showed rhinopharyngitis, a third suffered from pulmonary obstruction and nearly every second required oxygen therapy. However, no HBoV-specific symptoms were found. CONCLUSION: HBoV is a common pathogen causing viral respiratory tract infection in infants and young children. Among the here reported patients HBoV was the second most frequent identified pathogen. X-ray studies frequently revealed peribronchial and pneumonic infiltrates with only moderately elevated laboratory inflammatory markers. So far, no HBoV-specific clinical symptoms are known. Additional questions for example related to the way of transmission and optimal treatment remain to be investigated in prospective studies.     

Human bocavirus infection in children with respiratory tract disease

BACKGROUND: Human bocavirus (HBoV) is a ubiquitous, newly described member of the Parvoviridae family frequently detected in the respiratory tract of children, but only few reports provide data proving the link between HBoV and respiratory tract disease (RTD). OBJECTIVES: To evaluate the incidence of HBoV infection in children with RTD; to analyze the clinical features of HBoV infection; and to clinically compare HBoV, respiratory syncytial virus (RSV), and human metapneumovirus (HMPV) infections. STUDY DESIGN: A prospective 1-year study was conducted in children <5 years of age hospitalized with RTD and in asymptomatic control children. RESULTS: Human bocavirus was detected in 55 (10.8%) of the 507 children tested and in none of the 68 asymptomatic control children (P = 0.01). About 80% of these infections occurred between November and March. Coinfection with another virus was observed in 22 (40%) of the HBoV-positive children. HBoV viral load was significantly higher in samples from children with HBoV monoinfection than in those with coinfection. Subsequent detection of HBoV more than 2 months after the initial detection could be documented in 3 children. Clinical features associated with HBoV infection were similar to those observed with either RSV or HMPV infections, but HBoV infections were less severe than RSV infections. CONCLUSIONS: The difference observed in HBoV prevalence between children with RTD and controls provides support for a role of this virus in RTD. The frequent associations of HBoV with other respiratory viruses might be explained by the persistence of HBoV in the respiratory tract. The significance of HBoV viral load in nasopharyngeal secretions as a marker of pathogenicity merits further investigation.     

Human bocaviruses are commonly found in stools of hospitalized children without causal association to acute gastroenteritis

Human bocaviruses (HBoVs) may be grouped into respiratory (HBoV1) and enteric (HBoV2–4) types. We examined this association of HBoV types and clinical symptoms in 955 children who had acute gastroenteritis (AGE, n?=?172), acute respiratory tract infection (ARTI, n?=?545) or symptoms of both (n?=?238). Both nasal swab and stool specimens were studied for such patients. HBoV1 DNA was detected in 6.2 % of patients with ARTI and 9.2 % of patients with symptoms of both ARTI and AGE, but in only 1.7 % of patients with AGE alone. In about one half of the cases, HBoV1 was detected concomitantly in nasal swab and stool samples. HBoV2 was found in stool samples of patients with AGE (5.8 %), ARTI (5.1 %) and symptoms of both (5.5 %) but only rarely in nasal swabs. HBoV3 was found in the stools, but not in nasal swabs, in 0.6, 1.1 and 0.8 % of patients with, respectively, AGE, ARTI and both. HBoV4 was not found. All but one HBoV-positive stool sample of AGE patients contained a known gastroenteritis virus (rotavirus, norovirus, sapovirus, astrovirus or enteric adenovirus) that was probably responsible for the symptoms of the respective case. Sera of 30 HBoV-positive patients were available, and IgM antibodies for HBoVs were found in ten cases and HBoV DNA in eight of these. Conclusions: HBoV2 and HBoV3 were more commonly found in stool than in nasal swab samples, but the findings could not be causally linked with AGE. HBoV1 was commonly found in stool samples during ARTI, with or without gastrointestinal symptoms.     

Human bocavirus infection in hospitalized children during winter

Human bocavirus (HBoV) has recently been described as a common agent of acute upper and lower respiratory tract infections in children. We screened by polymerase chain reaction for HBoV nucleic acid nasopharyngeal aspirates from hospitalized children with negative culture and immunofluorescence assay for respiratory syncytial virus, influenza viruses, adenovirus, and parainfluenza viruses. HBoV was detected in 32 children (5.5%) and was the second virus identified in nasopharyngeal aspirates after respiratory syncytial virus. Most of the children had severe disease.     

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.     

Human bocavirus types 1, 2 and 3 in acute gastroenteritis of childhood

Aim: Recently identified human bocavirus (HBoV) types 2 and 3 have been associated with acute gastroenteritis in children. We studied 878 stool specimens from children with acute gastroenteritis and 112 controls (43 children with unspecified fever, 33 with respiratory tract infection and 36 healthy children) for known HBoVs. The same specimens were previously studied for rotaviruses, noroviruses, sapoviruses, adenoviruses, coronaviruses and aichivirus. Methods: HBoVs were detected by PCR and positive amplicons were sequenced to identify HBoV1, HBoV2, HBoV3 and HBoV4. Results: HBoV of any type was found in 85 (9.7%) cases of acute gastroenteritis and in 6 (5.4%) controls. HBoV1 was detected in 49 (5.6%) cases and 2 (1.8%) controls, HBoV2 in 29 (3.3%) cases and 2 (1.8%) controls and HBoV3 in 8 (0.9%) cases and 2 (1.8%) controls. No HBoV4 was found. HBoV as a single infection was found in 16 (1.8%) cases and in 6 (5.4%) controls; in the remaining cases, a known gastroenteritis virus was also found. Among the single HBoV infections, HBoV2 was the most common type with 8 (50%) cases. Conclusion: HBoVs are rarely found alone in children with acute gastroenteritis. Further studies are warranted to confirm a possible specific association of HBoV2 with gastroenteritis.     

Clinical and microbiological impact of human bocavirus on children with acute otitis media

Human Bocavirus (HBoV) as a newly discovered parvovirus has been commonly detected in respiratory tract infections. However, its role in acute otitis media (AOM) has not been well studied. We examined HBoV in Japanese children with AOM and evaluated the virus prevalence together with clinical manifestations and bacterial findings. Overall, 222 nasopharyngeal swabs and 176 middle ear fluids (MEF) samples were collected from 222 children with AOM (median age, 19 months) between May 2006 and April 2007. HBoV detection was performed by PCR and bacterial isolation by standard culture methods. HBoV was found in the nasopharyngeal aspirates of 14 children (6.3%) and in the MEF of six children (2.7%). When HBoV detection results were evaluated with clinical characteristics of children, resolution time of AOM was significantly longer (p=0.04), and rate of fever symptom was also higher in HBoV-positive group (p=0.04). Furthermore, we found positive correlation between detection of HBoV and Streptococcus pneumoniae in the MEF (p=0.004). Nevertheless, nasopharyngeal proportion of S. pneumoniae was similar between virus positive and negative groups. Furthermore, S. pneumoniae was detected as a single pathogen in all MEF of HBoV-positive cases but one, while it presents mixed with other pathogenic bacteria in nasopharynx. In conclusion, HBoV may worsen the clinical symptoms and prolong the clinical outcome of AOM in pediatric population. Finally, HBoV may prime the secondary bacterial infection in the middle ear in favor of S. pneumoniae.     

Clinical characteristics of human bocavirus infections compared with other respiratory viruses in Spanish children

BACKGROUND: Human bocavirus (HBoV) can be found in a substantial proportion of children with respiratory tract diseases. The relative importance of HBoV in viral respiratory tract illnesses is not yet well known. OBJECTIVE: In this study, we looked for HBoV in pediatric patients to determine the incidence of HBoV as single infection and compared it with other commonly found respiratory viruses to describe the clinical differences associated with HBoV infections in children. PATIENTS AND METHODS: A prospective study was conducted on children less than 14 years old, admitted with respiratory infection from September 2005 to August 2007 to the Pediatrics Department of the Severo Ochoa Hospital, Madrid, Spain. We studied the frequency of HBoV and 15 other respiratory viruses in nasopharyngeal aspirates and compared the clinical course of the infections caused by HBoV with those caused by other common respiratory viruses. RESULTS: Positive results were confirmed in 435 (61.2%) of the 710 children studied. A single virus was detected in 308 patients. HBoV was found in 99 (13.9%) samples, but it was recovered as a single virus in only 35. Most of patients with HBoV infection (75%) were aged < or =26 months. The most common clinical diagnosis was recurrent wheezing (53%), followed by bronchiolitis (32%). Clinical differences were observed between HBoV and respiratory syncytial virus (RSV) infections (children were older and bronchiolitis less frequent), adenovirus (fever less frequent in HBoV group), and rhinovirus-associated infections (less hypoxia in HBoV group). CONCLUSIONS: HBoV was the fourth most frequent single virus after RSV, rhinovirus, and adenovirus in children hospitalized because of respiratory infection. It was associated with recurrent wheezing and bronchiolitis showing a different clinical course from other virus in terms of diagnosis, fever, and age.     

Human bocavirus in children with acute lymphoblastic leukemia

A new human parvovirus, human bocavirus, has recently been identified in respiratory secretions, feces and serum. It is associated with lower and most likely also upper respiratory tract infections. Most commonly reported symptoms are cough, rhinorrhea, expiratory wheezing and fever, and the virus is preferentially detected in young children. We report three children with acute lymphoblastic leukemia who had acute febrile episodes with concomitant detection of human bocavirus in their respiratory secretions. One of them had five consecutive febrile episodes during 6 months, all associated with the presence of human bocavirus at varying viral loads, suggesting prolonged shedding or reactivation of the virus.     

90例儿童人博卡病毒感染临床分析

目的：探讨儿童人博卡病毒（HBoV）感染的临床特征。方法：采集843例下呼吸道感染患儿鼻、咽拭子标本,用多重RT-PCR方法检测HBoV和其他6种常见呼吸道病毒,分析HBoV阳性病例临床特征。结果：843例标本中检测出HBoV阳性90例（10.7%）,呼吸道合胞病毒（RSV）131例（15.5%）,流感病毒（IFV）117例（13.9%）,副流感病毒(PIV)84例（10.0%）,鼻病毒(RV)55例（6.5%）,冠状病毒(OC43)48例（5.7%）,人类偏肺病毒(HMPV)33例（3.7%）。HBoV合并其他呼吸道感染者45例（50%）,其中HBoV合并１种其他病毒感染者33例（37％）,合并2种其他病毒感染者11例（12％）,合并3种其他病毒感染者1例（1％）。伴喘息的患儿HBoV检出率高于不伴喘息的患儿（17.0% vs 9.2%,P<0.01）。HBoV阳性患儿常见的临床表现为频咳、喘息和发热。HBoV阳性组与RSV阳性组中喘息发生的构成比差异无统计学意义。结论：伴喘息发作的下呼吸道感染患儿中,HboV阳性检出率明显高于不伴喘息发作患儿,提示HBoV可能是除RSV外另一种引起儿童喘息的呼吸道病毒。HBoV与其他呼吸道病毒存在着混合感染。     

长沙市急性下呼吸道感染并粒细胞减少症111例病毒病原学分析

目的 探讨儿童急性下呼吸道感染并粒细胞减少症病毒病原学的特点.方法 选取湖南省人民医院2007年6月- 2008年10月111例急性下呼吸道感染并粒细胞减少症(粒细胞减少组)及1014例急性下呼吸道感染但粒细胞数正常的住院患儿(粒细胞正常组).患儿入院第2天收集鼻咽分泌物标本,采用反转录(RT) -PCR、PCR或巢式PCR扩增方法进行病毒基因检测,并将阳性产物测序,经序列测定及对比分析后确定为所检测病毒.结果 粒细胞减少组与粒细胞正常组病种构成及性别构成比较差异均无统计学意义(Pa＞0.05).粒细胞减少组37例未检出病毒,74例检出至少有1种病毒;各种病毒中,呼吸道合胞病毒(RSV)检出率最高,其次是副流感病毒3(PIV3)、鼻病毒(HRV)及人博卡病毒(HBoV).粒细胞正常组295例术检出病毒,719例检出至少有1种病毒;RSV检出率最高,其次是PIV3、HRV及HBoV.2组病毒总检出率及各种病毒检出率比较差异均无统计学意义(Pa＞0.05).2组年龄段分布差异有统计学意义(x2=8.89,P=0.012).其中1个月～1岁年龄段差异最大(X2=8.83,P=0.003).结论 1.急性下呼吸道感染住院患儿粒细胞减少的发生与病毒感染无明显相关.2.大于1岁的急性下呼吸道感染住院患儿更易出现粒细胞减少.3.急性下呼吸道感染住院患儿粒细胞减少与性别及疾病种类无关.     

Human bocavirus in children with respiratory tract infection in Shanghai: a retrospective study

Background  

Human bocavirus (HBoV) was first reported in 2005. The worldwide presence of HBoV in children with acute respiratory tract infection (ARTI) has been confirmed. This study aimed to understand the prevalence and clinical features of HBoV in children with ARTI in Shanghai and explore the causative implication of HBoV in ARTI.     

人类博卡病毒感染的持续喘息患儿临床特点分析

目的探讨人类博卡病毒（HBoV）感染的持续喘息患儿临床特点。方法从2006年4月至2007年1月共收集39例持续喘息患儿的呼吸道分泌物标本,其中33例通过纤维支气管镜检查吸取下呼吸道分泌物,6例为鼻咽分泌物。先进行呼吸道常见7种病毒筛查,并采用PCR的方法检测HBoV基因片段,对检出的阳性标本进行测序分析。结果（1）用免疫荧光快速诊断的方法在39例持续喘息患儿呼吸道分泌物中共检出呼吸道合胞病毒阳性13例,腺病毒阳性9例,副流感病毒3阳性4例,流感病毒A阳性2例。对检出的13例RSV阳性的标本进行病毒分离培养后提取RNA,RT-PCR进行呼吸道合胞病毒检测,检出8例阳性。（2）PCR和测序均证实,39例患儿呼吸道分泌物标本中有12例检出HBoV阳性。（3）12例HBoV阳性标本中的10例收集于冬春季,其余2例收集于夏秋季,与RSV的流行季节相似。（4）12例HBoV阳性患儿中7例出现发热,其中高热5例,明显高于RSV感染的患儿（1／13）,其胸X线改变出现间质性改变的例数也多于RSV感染患儿。其他如咳嗽、喘息、呼吸困难等临床表现两者差异均无统计学意义。结论HBoV感染是引起小儿下呼吸道感染的重要病毒病原之一,首次发现在持续喘息的患儿呼吸道分泌物中HBoV的阳性率高达31％。与RSV感染的患儿相比,HBoV感染发热例数相对多,但其他的临床症状与RSV相似。     

WU多瘤病毒在急性呼吸道感染儿童中的检出及初步临床研究

目的 了解WU多瘤病毒(WU polyomaviros,WUPyV)在小儿呼吸道感染中的检出情况及感染患儿的临床特点.方法 应用PCR技术,对2008年7月至2009年6月广东省汕头大学医学院第二附属医院儿科急性呼吸道感染住院患儿的呼吸道鼻咽抽取液及健康体检儿童呼吸道鼻咽抽取液进行WUPyV核酸检测,阳性结果 再进一步基因测序,并分析阳性患儿的临床资料.结果 771例患儿中WUPyV阳性15例,阳性率1.95%,其中单纯WUPyV感染9例(60%),合并其他病毒感染的有6例(40%).82例健康体检儿童WUPyV的PCR检查均阴性.所有WUPyV阳性患儿年龄均≤4岁,最小2个月,最大48个月,平均年龄18.8个月;男: 女=1.5:1,临床诊断主要是:支气管肺炎、细支气管炎、上呼吸道感染、支气管炎,其中1例重症患儿合并病毒性脑炎.结论 WUPyV可能是呼吸道感染病原体,其主要感染对象是婴幼儿,主要症状是咳嗽和喘息,个别有重症表现.     

住院呼吸道感染患儿博卡病毒检测分析

目的 了解人博卡病毒(HBoV)在天津地区急性呼吸道感染患儿中的检测情况和基因的遗传进化特征。方法 收集2012 年1~12 月确诊为急性呼吸道感染患儿的鼻咽抽吸物标本1 259 份,提取病毒核酸,采用实时荧光定量PCR 法检测HBoV,并采用PCR 法扩增阳性标本HBoV 核衣壳蛋白基因片段;随机选取部分产物进行测序确证,将所获得的序列与已知的HBoV 基因序列进行比对并进行系统进化分析;同时对所有标本进行其他多种呼吸道相关病毒检测。结果 1 259 份标本中HBoV 阳性检出率为4.53%(57/1 259),其中75%(43/57)发生在6~36 月龄的患儿;检出高峰主要集中在夏季(6~8 月);存在与其他病毒的混合感染情况。对其中36 份阳性标本的PCR 产物进行序列分析,证实检测结果确为HBoV,且与已知HBoV 的基因序列同源性较高。结论 天津地区部分儿童的急性呼吸道感染可能与HBoV 感染相关,且HBoV 感染在6~36 月龄的婴幼儿中更为常见,夏季为流行高峰;系统进化分析显示与已知HBoV 的基因序列同源性高,基因序列变异较小。     

���Ժ�������Ⱦ����540��������ԭѧ�ص����

目的了解北京地区门诊儿童急性呼吸道感染的病毒病原学特点。方法 2010年3月至2011年2月在北京儿童医院门诊就诊的急性呼吸道感染患儿540例,每例患儿采集咽拭子标本1份。采用多重PCR试剂检测常见呼吸道病毒核酸,包括呼吸道合胞病毒(RSV)A、B型,鼻病毒(RV),副流感病毒(PIV)1～4型,流感病毒(IFV)甲、乙型,腺病毒(ADV),人偏肺病毒(HMPV),人冠状病毒(HCoV),人博卡病毒(HBoV)及肠道病毒(EV)。结果 540例门诊采集的急性呼吸道感染患儿的咽拭子标本中,306例检出至少1种病毒,总阳性率56.7%。其中33例检出2种病毒,1例检出3种病毒,混合感染率为6.3%。各种病毒中,IFV检出率最高占16.7%,其次是ADV(12.8%),EV(7.8%),PIV(7.2%),。IFV中以甲型IFV为主(占95.6%),PIV中以PIV3型为主(占66.7%),RSV检出以RSVA型为主,占79.3%。结论病毒是引起儿童急性呼吸道感染的重要病原,北京儿童医院急性呼吸道感染的主要病毒病原是IFV、ADV、EV、PIV。     

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.     

长沙地区急性下呼吸道感染住院儿童人博卡病毒感染的初步研究

目的 了解人博卡病毒(HBoV)在长沙地区急性下呼吸道感染住院儿童中的流行情况及临床特征,比较分析其区域流行特点.方法 收集2007年9月 - 2008年3月长沙地区773份急性下呼吸道感染住院儿童鼻咽抽吸物(nasopharyngeal aspirates,NPAs)样本进行HBoV病毒NP1基因检测,将PCR阳性产物测序,并将所测序列在GenBank中进行比较分析.结果 773例样本中,HBoV阳性例数87例,HBoV感染患儿年龄为18 d ～ 64个月,冬春季节流行,主要的临床诊断与症状是支气管肺炎与咳嗽;所测序列与GenBank公布的不同地区的HBoV NP1基因核苷酸序列同源性达99.53%,氨基酸序列同源性达99.8%,对核苷酸序列作基因进化树分析显示属于1种基因型.结论 长沙地区部分急性下呼吸道感染儿童与人博卡病毒有关,且HBoV 感染在低年龄组的儿童中更常见;一种基因型在长沙地区流行.     

Parvovirus infections in children with hemolytic anemia

Acute episodes of erythroblastopenia in children with chronic hemolytic anemias have been recognized for a considerable length of time. In 1981, a small virus with a single strand of DNA, parvovirus B 19, was identified as the causative agent in most such episodes. Other diseases have been ascribed to parvovirus B 19, including erythema infectiosum or fifth disease, polyarthralgia, fetal death. Schonlein-Henoch disease, and bone marrow aplasia. In acute attacks of erythroblastopenia, anemia is the most prominent manifestation, but coexistence of neutropenia and thrombopenia has been reported. Hematologic disorders last for approximately ten days. The diagnosis of recent parvovirus B 19 infection rests on detection of specific IgM antibodies, or direct visualisation of the virus by electron microscopy. More recently, detection of the viral genome using molecular hybridization techniques has been achieved. In vitro studies have confirmed the inhibiting effect of parvovirus B 19 on red cell line progenitors, particularly CFU-E, but the exact mechanism of the inhibition remains uncertain. Other diseases due to parvovirus B 19 or other parvoviruses probably remain to be discovered.