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。     

人类博卡病毒感染所致细支气管炎的临床特点

目的探讨人类博卡病毒(HBoV)所致细支气管炎的临床特点。方法收集因细支气管炎于2007年6月-2008年5月住院治疗的271例患儿的呼吸道标本(鼻咽分泌物或咽拭子),应用多重PCR技术检测其HBoV,呼吸道合胞病毒(RSV),腺病毒(ADV),鼻病毒(RhV),流感病毒A、B型(FluA、FluB),副流感病毒1、3型(PIV1、PIV3),人类偏肺病毒(hMPV)9种病毒。随机选取RSV感染阳性患儿28例作为对照组。分析HBoV感染组与对照组患儿的临床特点。结果271例标本中,病毒阳性标本163例(60.1%)。其中HBoV阳性21例(12.9%),RSV阳性61例(37.4%);HBoV并其他病毒感染8例(38.1%),与RSV、FluA合并感染各3例,与ADV、RhV合并感染各2例,与hMPV合并感染1例。HBoV感染组与对照组患儿临床资料除在流行季节上有差异外,在性别、发病年龄、临床症状、肺部体征、辅助检查、住院天数、病情严重程度方面比较均无差异。结论HBoV是小儿细支气管炎的另一重要病原体,与RSV感染者在临床表现上无明显差异。HBoV细支气管炎的临床症状较轻,呼吸功能均属于轻中度受损,且以轻度为...     

2009—2010年苏州地区博卡病毒感染住院患儿临床特征分析

目的探讨苏州地区因急性呼吸道感染住院患儿中人类博卡病毒(human bocavirus,HBoV)感染的临床特征。方法收集2009年1月—2010年12月因急性呼吸道感染住院的3 826例患儿的痰标本,应用实时PCR检测HBoV DNA,直接免疫荧光法检测呼吸道合胞病毒、流感病毒(A、B)、副流感病毒(1～3)和腺病毒,同时采用逆转录PCR检测人偏肺病毒RNA,并进行细菌培养及荧光定量PCR检测支原体DNA,分析HBoV感染的临床特点及流行病学特征,并与呼吸道合胞病毒(RSV)进行比较。结果 3 816份标本共检测到HBoV 272例(7.13%),仅次于RSV;HBoV单独感染率为32.7%,与其他呼吸道病毒的合并感染率为18.38%,高于RSV和其他病毒的合并感染率(P<0.05)。HBoV感染全年均有发生,夏季最多;6～18月龄婴幼儿检出率最高,占48.17%。在住院患儿中,HBoV主要引起支气管肺炎(85.39%),临床症状主要表现为咳嗽(96.63%)、喘息(46.07%)、发热(56.18%)。与RSV相比,HBoV感染患儿的白细胞、中性粒细胞比例、CRP均高于RSV,差异有统计学意义(P<0.05)。结论 HBoV是苏州地区小儿呼吸道感染的重要病原体之一,有单独的致病性,与RSV相比,在年龄、季节分布、临床症状、实验室指标等方面有明显差异。     

618例儿童呼吸道感染的病毒病原学分析

目的 了解儿童常见呼吸道病毒感染的发生率,比较不同年龄段儿童呼吸道感染的病毒检出情况,并分析儿童喘息症状与病毒感染的关系.方法 以618例呼吸道感染住院患儿为研究对象,取其鼻咽分泌物进行七项呼吸道病毒抗原检测并分析其结果,包括呼吸道合胞病毒(RSV)、腺病毒(ADV)、甲型流感病毒(IFA)、乙型流感病毒(IFB)、副流感病毒Ⅰ、Ⅱ、Ⅲ(PIVⅠ、Ⅱ、Ⅲ).结果 (1)618例送检标本中,166例阳性,总阳性率为26.86％,其中RSV最高,阳性率为17.96％,其余依次为PIVⅢ(5.99％),IFA(1.62％),ADV(0.81％),PIVⅠ (0.49％);混合感染1例,阳性率为0.16％,为RSV与PIVⅠ混合感染.(2)14d～ ＜1岁、1岁～＜3岁、3岁～＜6岁及≥6岁不同年龄组病毒检出阳性率依次为35.04％、18.25％、17.11％、9.26％.(3)不同呼吸道感染性疾病病毒检出率不同,以毛细支气管炎检出率最高,为47.37％.(4)所检测呼吸道感染患儿中婴幼儿更易出现喘鸣体征,喘息患儿中以RSV检出阳性率最高,为42.17％.结论 RSV和PIVⅢ是儿童呼吸道感染的最常见病毒;呼吸道感染的儿童年龄越小,越容易发生病毒感染;喘息患儿中RSV感染率最高.     

2013~2018年重庆地区2 066例急性下呼吸道感染住院患儿呼吸道合胞病毒流行特征分析

目的 研究急性下呼吸道感染住院患儿呼吸道合胞病毒（RSV）检出率、流行规律及临床特征。方法 收集2013年6月至2018年5月于重庆医科大学附属儿童医院呼吸中心住院的2岁以下急性下呼吸道感染（ALRI）患儿鼻咽抽吸物,采用多重PCR检测16种常见呼吸道病毒,分析RSV流行特征。结果 共纳入2 066例ALRI住院患儿,病毒检出阳性1 595份（77.20%）。其中RSV阳性检出826份（39.98%）。RSV阳性样本中,RSV-A阳性410份（49.6%）,RSV-B阳性414份（50.1%）,RSV-A与RSV-B均阳性2份（0.2%）。2013~2014年、2016~2017年主导流行亚型为RSV-B,2014~2015年、2017~2018年以RSV-A为主要检出亚型,2015~2016年为RSV-A与RSV-B共同流行。冬季检出率最高。RSV合并人鼻病毒为最常见的2种病毒混合检出组合（123份）。该组患儿较单一RSV检出患儿更易出现喘息（P=0.030）。在2 066例患儿中,单一RSV检出298份,RSV混合其他病毒检出148份,其他病毒检出389份,病毒检出阴性241份。RSV单一检出组较其他病毒检出组和病毒检出阴性组月龄更小,更易发生呼吸困难、呼吸衰竭及重症下呼吸道感染（P < 0.0083）。RSV-A阳性患儿中的男性比例高于RSV-B阳性患儿（P=0.004）,而临床表现二者未见显著差异。结论 2013~2018年重庆地区RSV-A与RSV-B既可分别主导流行,也可共同流行;RSV为急性下呼吸道感染住院患儿最主要病毒病原,易导致重症下呼吸道感染;RSV-A和RSV-B感染患儿临床表现无差异,但RSV-A更易感染男性患儿。     

1165例急性下呼吸道感染住院儿童的病毒病原学分析

目的：了解长沙地区急性下呼吸道感染(ALRTI) 住院儿童中常见呼吸道病毒的流行特点,为本地区儿童ALRTI的防治提供依据。方法：收集2007年9月至2008年8月诊断为ALRTI的住院患儿鼻咽抽吸物标本1165份,采用RT-PCR方法检测呼吸道合胞病毒(RSV)、鼻病毒(HRV)、流感病毒A(IFVA)、流感病毒B(IFVB)、副流感病毒1~3(PIV1~3)、偏肺病毒(hMPV)、冠状病毒NL63(HCoV-NL63)及冠状病毒HKU1(HCoV-HKU1);PCR方法检测腺病毒(ADV)、博卡病毒(HBoV);巢式PCR方法检测多瘤病毒WU(WUPyV）和多瘤病毒KI(KIPyV)。并对阳性标本进行基因测序以证实。结果：1165份标本中有871份检出了病毒,总检出率74.76%,其中RSV最为常见,检出率为27.03%,其次为HRV（17.33%）、PIV3（13.73%）及新发现病毒HBoV(8.67%)和hMPV(6.52%)。病毒总检出率在男女之间差异无统计学意义,但男性PIV3、hMPV和HBoV的阳性检出率高于女性。病毒阳性检出率在各年龄组之间差异有统计学意义（χ2=10.934,P=0.027）,以6个月至1岁以内年龄组检出率最高。病毒总检出率在四季分布差异有统计学意义（χ2=12.307,P=0.006）,以冬季检出率最高。结论：病毒病原在长沙地区儿童ALRTI中占重要地位,其中RSV、HRV及PIV3是主要病毒病原,近年新发现的HBoV和hMPV也占较高比例;病毒检出率以6个月至1岁以内年龄组最高;冬季病毒总检出率高于其他季节。     

人博卡病毒载量与儿童急性下呼吸道感染临床特征相关性研究

目的了解人类博卡病毒(HBoV)在儿童急性下呼吸道感染中的检出情况,并探讨HBoV载量与儿童急性下呼吸道感染临床特征的相关性。方法收集2011年3月至2014年3月因急性下呼吸道感染住院患儿的鼻咽抽吸物(NPAs)1 554份,采用实时荧光定量PCR检测12种RNA病毒和ADV、HBoV 2种DNA病毒,并同时检测HBoV阳性患儿的病毒载量。结果 1 554份标本中1 212份(77.99%)检出病毒,275份(17.70%)HBoV检出阳性。HBoV阳性病例中3岁者占94.9%,男性多于女性。275例HBoV阳性病例中,单一感染45例(16.36%),混合感染230例(83.64%),两者病毒载量的差异无统计学意义(P0.05)。有发热症状的HBoV阳性患儿病毒载量高于无发热者,有喘息症状的病毒载量高于无喘息者,差异均有统计学意义(P0.05)。轻、中、重度组急性下呼吸道感染患儿之间的病毒载量差异无统计学意义(P0.05)。结论 HBoV是儿童急性下呼吸道感染重要病原之一。病毒载量高的患儿,临床更易出现发热、喘息等症状,但疾病严重程度及混合感染与病毒载量之间无显著相关性。     

急性下呼吸道感染患儿病毒病原学分析

目的了解昆明地区小儿急性下呼吸道感染(ALRI)患儿病毒病原谱及病毒病原学流行特点。方法对昆明市儿童医院内科2005-10—2006-09,临床诊断为急性下呼吸道感染712例住院患儿鼻咽分泌物,应用直接免疫荧光法进行呼吸道合胞病毒(RSV)、腺病毒(ADV)、流感病毒(IVA、B型)、副流感病毒(PIV1、2、3型)7种病毒抗原检测,并对呼吸道病毒流行特点进行分析。结果712例ALRI患儿中检出阳性病例206例,阳性率28.93%。新生儿、婴儿占阳性病例的77.18%。阳性标本中检出RSV177株,占阳性标本的85.92%(177/206),其次为PIV2、ADV各9株分别占4.37%(9/206),检出PIV35株占2.43%(5/206)、IVA、PIV1各3株占1.46%(3/206),一年中未检出IVB病毒株。206例阳性患儿中新生儿、婴儿、幼儿RSV感染阳性率分别为27.18%、42.23%、16.51%,年龄组间RSV阳性率比较,差异存在统计学意义。婴儿组中检出混合感染阳性病例3例,其中RSV合并ADV感染2例,PIV2合并ADV感染1例。RSV高峰流行季节在每年7月至次年2月,流行季节持续近8个月,3～6月病毒感染阳性率呈下降趋势,呼吸道病毒感染流行具有明显季节性。结论RSV是昆明地区婴儿ALRI的主要病原,呼吸道病毒类型及病原流行季节存在地区差异。     

2000年秋冬至 2002年夏北京地区急性呼吸道感染病毒病原学研究

为了解北京地区婴幼儿急性呼吸道感染的病毒病原。对2000年秋冬至2002年夏收集的1402份临床标本进行了病原分析。所有标本接种Hep-2和MDCK细胞进行病毒分离；鼻咽洗液脱落细胞涂片后经间接免疫荧光检测7种呼吸道病毒。RT-PCR鉴定RSV亚型；血凝及血凝抑制试验鉴定流感病毒型别；nested-PCR检测肠道病毒。1402份标本中672份咽拭子标本取自门诊患儿，730份鼻咽洗液标本取自住院患儿，结果：共有614份标本为病毒阳性，阳性率为43.8%。病毒阳性标本中呼吸道合胞病毒（RSV）占66.1%。并以A亚型为主；RSV阳性标本中91.4%来自诊断为毛细支气管炎的住院患儿。2001-2002年冬春季RSV感染比2000-2001年同期高25.1%。流感病毒阳性标本占总阳性标本的24.4%，其中89.3%来自门诊患儿；2000-2001年以乙型流感病毒为主，2001-2002年以甲3型为主，在冬春季还可检测到腺病毒和副流感病毒，夏季检测不到以上几种呼吸道病毒，利用nested-PCR方法检测2002年夏季收集的标本，发现7月份肠道病毒感染率相当高。提示RSV是北京地区冬春季婴幼儿急性下呼吸道感染首要病毒病原。流感病毒是婴幼儿急性上呼吸道感染首要病毒病原，肠道病毒是夏季婴幼儿呼吸道感染主要病毒病原，病毒分离，免疫荧光和PCR等方法的并用提高了病毒检出率，病毒病原的诊断可为临床诊断和治疗提供可靠依据。     

����ҽ�ƴ�ѧ��ͯҽԺ���Ժ�������ȾסԺ����������ԭѧ����

目的分析住院急性呼吸道感染(ARI)患儿病毒病原检测结果,为临床儿童急性呼吸道感染提供病毒病原学诊断依据。方法选择2003年4月至2005年3月重庆医科大学儿童医院呼吸内科住院治疗的急性呼吸道感染患儿,取其鼻咽分泌物做免疫荧光检测筛查7种常见呼吸道病毒抗原,包括呼吸道合胞病毒(RSV)、腺病毒、流感病毒A及B型、副流感病毒Ⅰ、Ⅱ、Ⅲ型,对检测标本阳性的病例进行统计分析。结果1052份标本中,阳性标本409份,占38.88%。其中RSV阳性标本360份,占总阳性标本例数的88.02%,副流感病毒Ⅲ37份占9.05%;RSV发病高峰时期在12月至次年2月和7、8月两个时期;RSV感染多见于3岁以下,发病高峰年龄为2～6个月,男女发病比例为2.24∶1。结论2003～2005年重庆地区急性呼吸道感染的病毒病原体仍以RSV为主。     

Distinctive clinical features of human bocavirus in children younger than 2 years

Background and objective

Clinical characteristics of human bocavirus (HBoV) infection have been studied worldwide, but their importance of those characteristics remains unknown. We investigated distinctive clinical features of HBoV-positive children with lower respiratory tract infection (LRTI).

Methods and results

During April 2007–July 2009, for 402 hospitalized children younger than 2 years with LRTI, we prospectively examined virus genomes in nasopharyngeal swabs for HBoV, respiratory syncytial virus (RSV), rhinovirus, metapneumovirus, parainfluenzavirus, and adenovirus. The HBoV genomes were identified in 34 patients (8.5%). Clinical and laboratory data of HBoV-positive and other virus/bacteria-negative patients (n?=?18) were analyzed and compared with data of RSV-single positive patients (n?=?99). The seasonal distribution of HBoV exhibits a concentration of cases during March–September, with most RSV cases occurring during winter in Japan. The minimum age of HBoV-positive patients was 5 months, although 44 patients (44%) with RSV were younger than 6 months. The main clinical features were respiratory distress and hypoxia. Hypoxia advances within 3 days after onset. The mean oxygen saturation on arrival was 92.8%, which was significantly lower than that in patients with RSV (p?<?0.001). White blood cell counts were similar among groups. However, the percentage of neutrophils in white blood cells were significantly higher in HBoV-positive patients (62 vs. 45%, p?<?0.001). Their prognoses were good. Their hospital stays were 6.6 days.

Conclusions

HBoV-single positive patients show several clinical characteristics, such as seasonality, age, hypoxia, and neutrophilia, which differ from those with RSV infection.     

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.     

哮喘高危婴幼儿喘息发作期病毒病原及过敏原检测分析

目的分析哮喘高危婴幼儿喘息发作期病毒病原学、过敏原分布，为喘息患儿的早期诊断与干预治疗提供帮助。方法选取2016年4月至2017年8月因喘息性支气管炎和喘息性支气管肺炎住院的135例哮喘高危婴幼儿为研究对象。采用荧光探针PCR法检测患儿鼻咽部抽吸物标本甲型流感病毒（Flu-A）、呼吸道合胞病毒（RSV）、腺病毒（ADV）、副流感病毒（PinF）、人鼻病毒（HRV）、人偏肺病毒（hMPV）、博卡病毒（HBoV）感染情况；采用ImmunoCAP技术检测患儿吸入性变应原、食物性变应原及总IgE浓度。结果 135例患儿中，鼻咽部抽吸物标本病毒检出阳性率为49.6%，各病毒检出阳性率由高到低依次为HRV 25.2%、HBoV 9.6%、RSV 8.1%、PinF 5.9%、Flu-A 3.7%、ADV 1.5%、hMPV 0.7%。HRV在1~3岁年龄组检出率高于<1岁组（P < 0.05）。过敏原筛查试验阳性率为59.3%，吸入性过敏原阳性率为44%，食物性过敏原阳性率为89%；吸入性过敏原中阳性率由高到低依次为尘螨77%、霉菌37%、花粉26%、动物皮屑9%；食物性过敏原中阳性率由高到低依次为鸡蛋白73%、牛奶68%。<1岁组吸入性过敏原阳性率大于1~3岁组（P < 0.05）；1~3岁组T-IgE水平明显高于<1岁组（P < 0.05）。病毒检出组吸入性过敏原阳性率大于病毒未检出组（P < 0.05）。第2次喘息患儿吸入性、食物性过敏原阳性率及T-IgE水平均高于第1次喘息患儿（P < 0.05）；吸入性过敏原尘螨、霉菌在第2次喘息患儿中阳性率高于第1次喘息患儿（P < 0.05）。结论早期HRV感染和吸入性过敏原阳性与哮喘高危婴幼儿喘息发生密切相关。     

Nasopharyngeal aspirate cytokine levels 1 yr after severe respiratory syncytial virus infection

Respiratory syncytial virus (RSV) infection is an important cause of recurrent wheezing in infants. Nevertheless, the link between RSV infection and wheezing has yet to be elucidated at the molecular level. Here, we present a preliminary study on the evolution of the immune response in the respiratory tract at long‐term after RSV infection. Twenty‐seven immune mediators were profiled in nasopharyngeal aspirates (NPAs) obtained from 20 children hospitalized due to a severe infection by RSV at discharge from hospital and again 1 yr later. The same mediators were profiled in parallel in NPAs from 12 healthy controls. In the year following discharge, 85% (17/20) of children of the RSV group suffered at least one episode of wheezing documented by the pediatrician. On the contrary, wheezing episodes were observed only in 25% (3/12) of children in the control group. While most of the mediators profiled returned to normal levels by 1 yr after discharge from hospital, RSV children showed a persistent nasal hyper‐secretion of VEGF, G‐CSF, IL‐10, IL‐6, IFN‐γ, IL‐7 and IL‐13. In previous works VEGF, IL‐10 and IFN‐γ have been put in relation with the pathogenesis of post‐virus induced asthma. G‐CSF, IL‐6, IL‐7 and IL‐13 are increased in respiratory and plasma samples of asthmatic patients. Here, we evidence for the first time a persistent elevation of these mediators as late as 1 yr after severe RSV disease resolution, reinforcing their possible implication in the pathogenesis of wheezing.     

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.     

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.