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.     

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.     

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.     

粤东地区毛细支气管炎病毒病原谱的变迁探究

目的探讨近年来粤东地区毛细支气管炎病毒病原学的构成现状。方法收集粤东地区2007年7月至2010年6月3年间毛细支气管炎患儿的咽拭子共508份,采用多重PCR方法检测呼吸道合胞病毒、腺病毒、流感病毒A型、流感病毒B型、副流感病毒1型、副流感病毒3型、鼻病毒、人类博卡病毒、人类偏肺病毒、WU多瘤病毒,共8种lO型病毒。结果①508例患儿中男374例（73．6％）,女134例（26．4％）。②508例患儿中1岁以下年龄组393例（77．4％）,病毒检出率为77．2％;1岁以上年龄组115例（22．6％）,病毒检出率为22．8％。③2007年7至2008年6月病毒阳性率为47．5％（77／162）,病毒检出第1位为呼吸道合胞病毒（33．7％）,新发现呼吸道病毒（人类博卡病毒、人类偏肺病毒、wu多瘤病毒）占14．3％;2008年7月至2009年6月病毒阳性率为51．7％（124／240）,病毒检出第1位为流感病毒A型（38．4％）,新发现呼吸道病毒占6．4％;2009年7月至2010年6月病毒阳性率为45．3％（48／106）,病毒检出第1位为鼻病毒（22．4％）,新发现呼吸道病毒占20．9％。④3年间病毒混合感染率分别为20．8％、42．7％、27．1％。结论①毛细支气管炎患儿中男孩多见,1岁以下年龄组发病率及病毒检出率均高于1岁以上年龄组。②鼻病毒、流感病毒A型在不同年度是小儿毛细支气管炎首位病原体,既往研究中占首位的呼吸道合胞病毒有逐年下降趋势。③新发现呼吸道病毒在小儿毛细支气管炎病例中检出,并有逐年上升趋势。④毛细支气管炎病例中存在不同病毒混合感染的现象。     

Impact of viral infections in children with community‐acquired pneumonia: results of a study of 17 respiratory viruses

Please cite this paper as: Esposito et al. (2012) Impact of viral infections in children with community‐acquired pneumonia: results of a study of 17 respiratory viruses. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00340.x. Background Little is known about the prevalence of viral infections in children with community‐acquired pneumonia (CAP). Objectives To describe the clinical and virological data collected from children with radiographically confirmed CAP in whom 17 respiratory viruses were sought in respiratory secretion samples during the acute phase of the disease. Patients and methods The study involved 592 children with radiographically confirmed CAP whose respiratory secretion samples were tested using the Luminex xTAG Respiratory Virus Panel Fast assay, which simultaneously detects influenza A virus, influenza B virus, respiratory syncytial virus (RSV)‐A and ‐B, parainfluenzavirus‐1, ‐2, ‐3, and ‐4, adenovirus, human metapneumovirus, coronaviruses 229E, NL63, OC43, and HKU1, enterovirus/rhinovirus, and bocavirus. A real‐time PCR assay was used to identify the rhinovirus in the enterovirus/rhinovirus‐positive samples. Results A total of 435 children (73·5%) were positive for at least one virus: the most frequently detected was RSV, which was found in 188 (31·7%), followed by rhinovirus (n = 144, 24·3%), bocavirus (n = 60, 10·1%), influenza viruses (n = 57, 9·6), and hMPV (n = 49, 8·2%). Viral co‐infections were found in 117 children (19·7% of the enrolled children; 26·9% of those with viral infections). Marginal differences were found between the infections owing to a single virus. Co‐infections showed radiographic evidence of alveolar pneumonia significantly more frequently than single infections (OR 1·72, 95% CI 1·05–2·81). Conclusions The findings of this study highlight the importance of respiratory viruses (mainly RSV and rhinovirus) in children with CAP and show the characteristics of both the single infections and co‐infections associated with the disease.     

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.     

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.     

上海地区643例呼吸道感染患儿鼻咽分泌物病毒病原检测分析

目的 探讨上海地区急性儿童呼吸道感染的病毒病原学特点,为临床诊断和治疗提供参考.方法 收集2012年1月至2013年12月,在上海交通大学医学院附属第九人民医院、新华医院、普陀区中心医院因急性呼吸道感染就诊的643例患儿的鼻咽抽吸物标本,采用反转录聚合酶链反应(RT-PCR)和聚合酶链反应(PCR)方法检测呼吸道相关病毒HRV、RSV、ADV、IFV (A、B型)、PIV(1～4型)、HMPV、HCoV-NL63,HCoV-HKU1、HBoV.结果 共643例患儿采集了鼻炎抽吸物标本,年龄从11d至12岁,中位年龄为12个月,男402例,女241例;共检出病毒感染阳性标本369份,总检出率57.4％ (369/643),2012年RSV检出率最高,2013年ADV检出率最高,新发现病毒中HBoV检出率最高,未检测到冠状病毒NL-63.6个月到1岁年龄段病毒的检出率最高,随年龄增长,病毒的检出率逐渐下降,病毒检出贯穿全年,诊断包括上、下呼吸道感染.结论 病毒是引起上海地区儿童呼吸道感染的主要病原,以RSV和ADV为丰.     

Epidemiological and clinical features of respiratory viral infections in hospitalized children during the circulation of influenza virus A(H1N1) 2009

Please cite this paper as: Zuccotti et al. (2011) Epidemiological and clinical features of respiratory viral infections in hospitalized children during the circulation of influenza virus A(H1N1) 2009. Influenza and Other Respiratory Viruses 5(6), e528–e534. Background Seasonal influenza viruses and respiratory syncytial virus (RSV) are primary causes of acute respiratory tract infections (ARTIs) in children. New respiratory viruses including human metapneumovirus (hMPV), human bocavirus (hBoV), and influenza 2009 A(H1N1) virus have a strong impact on the pediatric population. Objectives To evaluate epidemiological and clinical features of ARTIs in hospitalized children. Methods From December 1, 2008, to December 31, 2009, all children under age fifteen (n = 575) hospitalized for ARTIs were investigated for influenza A (subtype H1N1, H3N2, and 2009 H1N1) and B, RSV A and B, hMPV, and hBoV by PCR. Results Fifty‐one percent of samples were positive for these respiratory viruses. The frequencies of virus detection were RSV 34·1%, hBoV 6·8%, hMPV 5%, seasonal influenza A 5%, and seasonal influenza B 0%. From April 2009, 11·6% of collected samples were influenza 2009 A(H1N1) positive. Respiratory syncytial virus activity peaked in January, hBoV in February, and hMPV in April. Seasonal influenza A was detected only between January and April 2009, while influenza 2009 A(H1N1) peaked in November. Respiratory syncytial virus and hMPV were mainly associated with lower respiratory tract infections (LRTIs) and with necessity of O₂ administration. The 2009 pandemic influenza was more frequently detected in elder children (P < 0·001) and was associated with higher, longer‐lasting fevers compared with other viral infections (P < 0·05). Conclusions All considered viruses were involved in LRTIs. The primary clinical relevance of RSV and a similar involvement of both seasonal influenza and emerging viruses investigated were observed on the pediatric population.     

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。     

急性下呼吸道感染住院儿童病原及临床流行病学分析

目的 了解上海部分地区全年儿童急性下呼吸道感染(ALRTI)的病原谱及临床流行病学特征,为临床抗感染及病原检测提供依据.方法 933例复旦大学附属儿科医院2007年1月至12月ALRTI住院患儿,负压吸取咽部以下深部痰液1～2 mL,作细菌培养,并检测呼吸道合胞病毒(RSV),腺病毒(ADV),A、B型流感病毒(IFV),1、2及3型副流感病毒(PIV)等7种常见呼吸道病毒抗原,实时荧光定量PCR检测人偏肺病毒(hMPV)RNA及支原体和衣原体DNA.结果 992份ALRTI儿童痰标本中,细菌培养阳性225份,病毒检测阳性316份,支原体和衣原体阳性分别是74份与31份,混合感染标本118份,总标本病原学检出率为53.9%.RSV阳性标本268份,为最重要的感染病原,冬季为RSV感染高峰,3月龄以下儿童检出率为36.4%,3足月到6月龄以下儿童检出率为49.5%,2岁以下儿童占92.5%.RSV阳性标本中,79.5%的患儿有喘息表现.330份7种常见病毒检测阴性标本中,hMPV检出率为2.1%,患儿均无喘息表现.检出大肠埃希菌40株、肺炎克雷伯菌33株、肺炎链球菌32株、金黄色葡萄球菌20株、凝固酶阴性葡萄球菌19株、流感嗜血杆菌和副流感嗜血杆菌分别为17株和16株、卡他莫拉菌布兰汉亚种16株、铜绿假单胞菌15株,为主要的致病菌.975份标本中支原体和衣原体检出率分别为7.6%和3.2%.结论 RSV仍为儿童ALRTI最主要的病原,尤其在2岁以下儿童.RSV感染易表现为儿童喘息发作,冬季为流行高峰.2007年hMPV流行强度较弱.上海部分地区仍有40%以上ALRTI患儿感染病原未明.     

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.     

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 coronavirus NL63 infections in infants hospitalised with acute respiratory tract infections in South Africa

Background Human coronavirus NL63 (HCoV‐NL63) is a novel respiratory virus which is associated with respiratory tract infections in children. Objective To determine the role of HCoV‐NL63 in infants and young children hospitalised with acute respiratory tract infections (ARI) in Cape Town, South Africa. Methods Respiratory specimens were collected from 1055 infants and young children hospitalised with ARI in 2003–2004. Samples were screened by RT‐PCR to detect HCoV‐NL63 and human metapneumovirus (hMPV). Standard shell vial culture and immunofluoresence was used to detect the common respiratory viruses including RSV, influenza A and B viruses, parainfluenza viruses 1, 2, 3, adenovirus and CMV. Results A respiratory virus was found in 401/1055 (38·0%) samples. HCoV‐NL63 was detected in 9/1055 (0·85%) with peak activity during autumn (67%). Most patients had a diagnosis of pneumonia or lower respiratory tract infection (6/9; 67%). Conclusions This is the first report of HCoV‐NL63 infections in hospitalised children in Africa. During the 2‐year period HCoV‐NL63 played a minor role in ARI in children.     

Etiology of acute lower respiratory tract infection in children at Srinagarind Hospital, Khon Kaen, Thailand

We investigated the etiology of acute lower respiratory infection (ALRI) in children under 5 admitted to Srinagarind Hospital. The causative bacteria and viruses were determined by hemoculture and viral isolation from blood and nasopharyngeal aspirate samples. Antigens of respiratory syncytial virus (RSV) and Chlamydia trachomatis were detected using EIA. The 74 children less than 5 years of age with ALRI enrolled in our study were diagnosed with pneumonia (75.7%), croup (16.2%), and bronchiolitis (8.1%), respectively. Examination of blood or nasopharyngeal aspirate revealed viral or bacterial infections in 26 and 22 cases, respectively, whereas 5 of the children aged under 1 year (10%) were diagnosed with pneumonia caused by Chlamydia trachomatis. RSV was the most common virus detected (24.3%) and was associated with pneumonia and bronchiolitis, while the parainfluenza virus was the primary cause of croup. In cases of pneumonia, bacterial infections were identified in almost all of the cases: and Streptococcus pneumoniae and Haemophilus influenzae were the most commonly isolated (at 8.9% each). Mixed infections were detected in 8 cases (10.8%). The incidence of RSV infection peaked during the especially warm and cool seasons, whereas the bacterial infections were primarily associated with the relatively cool season. Our study indicates that a combined pneumococcal and Hib vaccine and a RSV vaccine would reduce the high rate of pneumonia in children under 5 years of age in Northeast Thailand.     

Respiratory Syncytial Virus Coinfections With Rhinovirus and Human Bocavirus in Hospitalized Children

It is not clearly established if coinfections are more severe than single viral respiratory infections.The aim of the study was to study and to compare simple infections and viral coinfections of respiratory syncytial virus (RSV) in hospitalized children.From September 2005 to August 2013, a prospective study was conducted on children younger than 14 years of age, admitted with respiratory infection to the Pediatric Department of the Severo Ochoa Hospital, in Spain. Specimens of nasopharyngeal aspirate were taken for virological study by using polymerase chain reaction, and clinical data were recorded. Simple RSV infections were selected and compared with double infections of RSV with rhinovirus (RV) or with human bocavirus (HBoV).In this study, 2993 episodes corresponding to 2525 children were analyzed. At least 1 virus was detected in 77% (2312) of the episodes. Single infections (599 RSV, 513 RV, and 81 HBoV) were compared with 120 RSV-RV and 60 RSV-HBoV double infections. The RSV-RV coinfections had fever (63% vs 43%; P < 0.001) and hypoxia (70% vs 43%; P < 0.001) more often than RV infections. Hypoxia was similar between single or dual infections (71%). Bronchiolitis was more frequent in the RSV simple group (P < 0.001). Pediatric intensive care unit admission was more common in RSV simple or RSV-RV groups than in the RV monoinfection (P = 0.042).Hospitalization was longer for both RSV simple group and RSV-HBoV coinfection, lasting about 1 day (4.7 vs 3.8 days; P < 0.001) longer than in simple HBoV infections. There were no differences in PICU admission. RSV single group was of a younger age than the other groups.Coinfections between RSV-RV and RSV-HBoV are frequent. Overall viral coinfections do not present greater severity, but have mixed clinical features.     

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.     

Multiple versus single virus respiratory infections: viral load and clinical disease severity in hospitalized children

Please cite this paper as: Martin et al. (2012) Multiple versus single virus respiratory infections: viral load and clinical disease severity in hospitalized children. Influenza and Other Respiratory Viruses 6(1), 71–77. Background Molecular testing for viral pathogens has resulted in increasing detection of multiple viruses in respiratory secretions of ill children. The clinical impact of multiple virus infections on clinical presentation and outcome is unclear. Objectives To compare clinical characteristics and viral load between children with multiple virus versus single virus illnesses. Patients/methods Eight hundred and ninety‐three residual nasal wash samples from children treated for respiratory illness at Children’s Hospital, Seattle, from September 2003 to September 2004 were evaluated by quantitative PCR for respiratory syncytial virus (RSV), human metapneumovirus (hMPV), influenza (Flu), parainfluenza, adenoviruses, and coronaviruses (CoV). Illness severity and patient characteristics were abstracted from medical charts. Results Coinfections were identified in 103 (18%) of 566 virus‐positive samples. Adenovirus was most commonly detected in coinfections (52%), followed by CoV (50%). Illnesses with a single virus had increased risk of oxygen requirement (P = 0·02), extended hospital stays (P = 0·002), and admissions to the inpatient (P = 0·02) or intensive care units (P = 0·04). For Adv and PIV‐1, multiple virus illnesses had a significantly lower viral load (log₁₀ copies/ml) than single virus illnesses (4·2 versus 5·6, P = 0·007 and 4·2 versus 6·9, P < 0·001, respectively). RSV, Flu‐A, PIV‐3, and hMPV viral loads were consistently high whether or not another virus was detected. Conclusions Illnesses with multiple virus detections were correlated with less severe disease. The relationship between viral load and multiple virus infections was virus specific, and this may serve as a way to differentiate viruses in multiple virus infections.     

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.