Human metapneumovirus and respiratory syncytial virus, Brazil

We describe the epidemiologic and clinical characteristics of 111 children attending clinics and hospitals in Aracaju, northeast Brazil, with acute respiratory infections attributable to human metapneumovirus (HMPV), respiratory syncytial virus (RSV), or both in May and June 2002. Fifty-three (48%) children were infected with RSV alone, 19 (17%) with HMPV alone, and 8 (7%) had RSV/HMPV co-infections.     

Human metapneumovirus infections in hospitalized children

We evaluated the percentage of hospitalizations for acute respiratory tract infections in children < or =3 years of age attributable to human metapneumovirus (HMPV) and other respiratory viruses in a prospective study during winter and spring 2002. We used real-time polymerase chain assays and other conventional diagnostic methods to detect HMPV, human respiratory syncytial virus (HRSV), and influenza viruses in nasopharyngeal aspirates of children. HMPV was detected in 12 (6%) of the 208 children hospitalized for acute respiratory tract infections, HRSV in 118 (57%), and influenza A in 49 (24%). Bronchiolitis was diagnosed in 8 (68%) and pneumonitis in 2 (17%) of HMPV-infected children; of those with HRSV infection, bronchiolitiss was diagnosed in 99 (84%) and pneumonitis in 30 (25%). None of the HMPV-infected children was admitted to an intensive-care unit, whereas 15% of those with HRSV or influenza A infections were admitted. HMPV is an important cause of illness in young children with a similar, although less severe, clinical presentation to that of HRSV.     

Human metapneumovirus detection in patients with severe acute respiratory syndrome

We used a combination approach of conventional virus isolation and molecular techniques to detect human metapneumovirus (HMPV) in patients with severe acute respiratory syndrome (SARS). Of the 48 study patients, 25 (52.1%) were infected with HMPV; 6 of these 25 patients were also infected with coronavirus, and another 5 patients (10.4%) were infected with coronavirus alone. Using this combination approach, we found that human laryngeal carcinoma (HEp-2) cells were superior to rhesus monkey kidney (LLC-MK2) cells commonly used in previous studies for isolation of HMPV. These widely available HEp-2 cells should be included in conjunction with a molecular method for cell culture followup to detect HMPV, particularly in patients with SARS.     

Respiratory tract reinfections by the new human Metapneumovirus in an immunocompromised child

The human Metapneumovirus (HMPV), a new member of the Paramyxoviridae family, has been recently associated with respiratory tract infections in young children. We report the case of a young, immunocompromised child who had severe lower respiratory tract infections during two consecutive winter seasons caused by genetically distinct HMPV strains.     

Human metapneumovirus, Peru

We retrospectively studied 420 pharyngeal swab specimens collected from Peruvian and Argentinean patients with influenzalike illness in 2002 and 2003 for evidence of human metapneumovirus (HMPV). Twelve specimens (2.3%) were positive by multiple assays. Six specimens yielded HMPV isolates. Four of the 6 isolates were of the uncommon B1 genotype.     

Human metapneumovirus and severity of respiratory syncytial virus disease

We screened 23 children with severe respiratory syncytial virus (RSV) disease and 23 children with mild RSV disease for human metapneumovirus (HMPV). Although HMPV was circulating in Connecticut, none of the 46 RSV-infected patients tested positive for HMPV. In our study population, HMPV did not contribute to the severity of RSV disease.     

湖南省2012-2014年发热呼吸道症候群哨点监测结果及分析

目的 通过“发热呼吸道症候群监测”了解湖南省主要呼吸道病毒流行情况及病原谱分布,为发热呼吸道症候群防控及临床诊疗提供科学依据。 方法 2012年1月-2014年12月,从符合发热呼吸道症候群定义的患者身上采集鼻/咽拭子、肺泡灌洗液、痰液样本。采用基于毛细管凝胶电泳的“9+7呼吸道病毒多重PCR检测法”对标本中流感病毒(Flu)、呼吸道腺病毒(AdV)、呼吸道合胞病毒(RSV)、人鼻病毒(hRV)、副流感病毒(PIV)、偏肺病毒(HMPV)、人博卡病毒(hBoV)和人冠状病毒(hCoV)共8种病毒的16个亚型进行核酸检测。使用SPSS17.0统计学软件对个案信息及检测结果进行统计学分析。 结果 2012年1月-2014年12月,从哨点医院采集各类呼吸道标本共961份,其中男性病例标本595份,占61.91%;女性病例标本366份,占38.09%。在961份已检测的标本中,通过PCR检出阳性标本456份,阳性检出率为47.45%。男、女病例标本的阳性检出率差异无统计学意义(P>0.05)。按年龄将病例分为7个年龄组,各年龄组的阳性检出率分别为 1岁以下(52.80%)、1~2岁(66.53%)、2~5岁(49.86%)、6~15岁(25.56%)、16~49岁(11.11%)、50~64岁(17.39%)和65岁以上(19.40%)。在456份病毒阳性的标本中,检出混合感染48例,非混合感染408例。在检出的呼吸道病毒中,AdV、RSV和Flu所占的比例最大(病原谱构成比分别为25.90%、21.31%和17.73%),其次为hRV(14.14%)和PIV(11.75%);HMPV(4.78%)和hBoV(3.98%)检出较少,而hCoV只有两例阳性被检出。男性、女性的病原构成差异无统计学意义(P>0.05)。各年龄段的病原构成差异有统计学意义(P<0.05),其中2岁以下的儿童病例中检出的病毒以RSV(29.36%)和AdV(23.02%)为主,其次为PIV(13.10%)、hRV(11.90%)和Flu(11.11%);2~5岁的儿童病例中,AdV所占比例最大(34.02%),其次为hRV(18.56%)、Flu(18.04%)和RSV(15.46%);6~15岁少儿病例中以Flu(31.43%)和PIV(34.29%)为主,其次为AdV(17.14%)和hRV(14.29%);在16~49岁的病例中,只有Flu检出;在50岁以上老年病例中,病原构成以Flu(68.41%)为主,其余为PIV(10.53%)、HMPV(10.53%)和RSV(10.53%)。监测还发现,Flu、AdV有夏季和冬春季两个流行高峰;RSV有冬春季流行高峰;hRV有秋冬季流行高峰。 结论 所监测的8种呼吸道病毒是引发严重急性呼吸道住院病例的重要病原。5岁以下儿童及65岁以上的老人可能是主要的易感人群。其中,RSV、AdV、 Flu可能是引发儿童病毒性呼吸道感染的主要病原,而Flu则可能是引发成人病毒性呼吸道感染的主要原因。因此,应将这几种病毒作为呼吸道病毒防控的重点,进行更多的监测和更深入的研究。     

Human metapneumovirus RNA in encephalitis patient

We describe a fatal case of encephalitis that might be correlated with primary human metapneumovirus (HMPV) encephalitis. Postmortem HMPV RNA was detected in brain and lung tissue samples from the patient. Furthermore, HMPV RNA was found in culture fluids from cells coincubated with lung tissue.     

Novel human metapneumovirus sublineage

In a pediatric surveillance network, 287 (5.1%) of 5,580 specimens from patients with acute respiratory infections tested positive for human metapneumovirus (HMPV). Phylogenetic analysis of N- and F-gene sequences of identified HMPV showed that 30% belonged to a novel phylogenetic cluster.     

Genetic variability of human metapneumovirus amongst an all ages population in Cambodia between 2007 and 2009

First identified in 2001, human metapneumovirus (HMPV) is a novel pathogen and causative agent of acute respiratory tract infection. Re-infection with HMPV is common, and currently there is no available vaccine against HMPV infection. Two genotypes of HMPV have been identified, A and B, both of which can be divided further into at least two distinct sub-genotypes. Here we report the results of the first study to investigate the genetic variability of HMPV strains circulating within Cambodia. The overall incidence of HMPV infection amongst an all-ages population of patients hospitalised with ALRI in Cambodia during 3 consecutive years, between 2007 and 2009, was 1.7%. The incidence of HMPV infection was highest amongst children less than 5 years of age, with pneumonia or bronchopneumonia the most frequent clinical diagnoses across all age groups. The incidence of HMPV infection varied annually. As anticipated, genetic diversity was low amongst the conserved F gene sequences but very high amongst G gene sequences, some strains sharing as little as 56.3% and 34.2% homology at the nucleotide and amino acid levels, respectively. Simultaneous co-circulation of strains belonging to the HMPV sub-genotypes B1, B2 and lineage A2b, amongst patients recruited at 2 geographically distinct provincial hospitals, was detected. Sub-genotype B2 strains were responsible for the majority of the infections detected, and a significant (p  =  0.013) association between infection with lineage A2b strains and disease severity was observed.     

Novel HLA-A2-restricted human metapneumovirus epitopes reduce viral titers in mice and are recognized by human T cells

Human metapneumovirus (HMPV) is a major cause of morbidity and mortality from acute lower respiratory tract illness, with most individuals seropositive by age five. Despite the presence of neutralizing antibodies, secondary infections are common and can be severe in young, elderly, and immunocompromised persons. Preclinical vaccine studies for HMPV have suggested a need for a balanced antibody and T cell immune response to enhance protection and avoid lung immunopathology. We infected transgenic mice expressing human HLA-A*0201 with HMPV and used ELISPOT to screen overlapping and predicted epitope peptides. We identified six novel HLA-A2 restricted CD8⁺ T cell (T_CD8) epitopes, with M_39–47 (M39) immunodominant. Tetramer staining detected M39-specific T_CD8 in lungs and spleen of HMPV-immune mice. Immunization with adjuvant-formulated M39 peptide reduced lung virus titers upon challenge. Finally, we show that T_CD8 from HLA-A*0201 positive humans recognize M39 by IFNγ ELISPOT and tetramer staining. These results will facilitate HMPV vaccine development and human studies.     

2015 - 2017年上海市黄浦区成人急性呼吸道感染病例病原学监测分析

目的 探索上海市黄浦区成人急性呼吸道感染病例（ARI）的病原体感染分布特征。方法 采集黄浦区监测点369例急性呼吸道感染病例的呼吸道标本进行多重PCR以及细菌培养等检测,分析病原体感染的流行特征。结果 2015 - 2107年共收集了369例ARI病例,检出12种病原体,病原体检出阳性率为55.01%（203/369）。其中甲型流感病毒阳性率最高,为25.56%（98/369）,乙型流感病毒阳性率为9.76%（36/369）,肺炎克雷伯菌为4.61%（17/369）,鼻病毒/肠道病毒为3.79（14/369）。检出的病原体感染中混合感染率为5.42%（20/369）。不同年龄组感染率有所不同,16～24岁年龄组感染率较高（68.00%,17/25）,60岁及以上年龄组感染率较低（44.90%,66/147）。冬季和夏季是呼吸道病原体阳性率较高,检出阳性率分别为69.11%（85/123）、60.32%（76/126）。流感有季节性特征,夏季阳性率为17.34%（64/369）,冬季阳性率为14.36%(53/369）。结论 上海市黄浦区成人呼吸道感染病例中病原体主要以病毒为主,其中季节性流感检出阳性率最高。不同年龄组感染率有差异,冬季和夏季是呼吸道病原体感染流行的高峰。     

Soluble recombinant human metapneumovirus G protein is immunogenic but not protective

Human metapneumovirus (HMPV) expresses the major surface glycoproteins F and G. We evaluated the protective efficacy of immunization with G. We generated a recombinant form of G ectodomain (GΔTM) that was secreted from mammalian cells and purified by affinity chromatography. We tested the immunogenicity of GΔTM in cotton rats. Animals were immunized with PBS, GΔTM alone or adjuvanted, or were infected once with HMPV, and challenged with live HMPV at 28 days. Animals vaccinated with adjuvanted and non-adjuvanted GΔTM developed high levels of serum antibodies to both recombinant and native G protein; however, vaccinated animals did not develop neutralizing antibodies and were not protected against virus challenge. Unlike the analogous non-fusion glycoproteins of other human paramyxoviruses, HMPV G does not appear to be a protective antigen. This represents an unusual feature of HMPV.     

武汉地区儿童急性呼吸道感染的常见病原体检测

目的 本研究主要是检测15岁及以下急性呼吸道感染儿童病毒及非典型细菌,了解这些病原体在武汉地区的流行情况。 方法 收集2012年9月－2017年8月武汉大学人民医院住院儿科41 434例拟诊断为急性呼吸道感染(acute respiratory infection,ARI)的患儿血清,采用间接免疫荧光法检测其中九种常见病原体的IgM抗体,分别为:腺病毒(including adenovirus,ADV)、Q热立克次体(Coxiella burnetii ,COX)、肺炎衣原体(Chamydophila pneumonia,CP)、甲型流感病毒(influenza A virus,FluA)、乙型流感病毒(influenza B virus,FluB)、嗜肺军团菌I型(Legionella pneumophila 1,LPN1)、肺炎支原体(Mycoplasma pneumoniae,MP)、副流感病毒(parainfluenza virus,PIV)、呼吸道合胞病毒(respiratory syncytial virus,RSV)。 结果 在检测的41 434例样本中,有20 373例检测出阳性(49.17%),以MP的检出最高16 435例(39.67%),其次为FluB和PIV,分别为7 541例(18.20%)、2 297例(5.54%)。FluB在2013年和2014年秋季有小流行;ADV在2013年和2014年春夏流行趋势明显;PIV在2013年冬季、2014年春季、2016年夏季和2017年春夏流行趋势明显;COX在2013年夏季和2014年秋季流行;FluA和LPN1在2013年夏季有小流行。九种病原体中ADV、CP、FluB、LPN1、MP、PIV、RSV病原体检出率在各年龄组之间差异有统计学意义(P<0.05),<1岁年龄组中的病原体总检出率明显低于其他组(P<0.05)。混合感染方式较复杂,2种病原体混合感染中,MP+FluB混合感染最多(3 656例,检出率为8.82%)。 结论 武汉地区引起儿童ARI的病原体主要是MP、FluB和PIV;各种病原体检出率具有一定季节性且在不同年龄段有一定差异;混合感染比较普遍,主要是MP+FluB混合感染。     

Human metapneumovirus infection among children, Bangladesh

We confirmed circulation of human metapneumovirus (HMPV) among children with febrile and respiratory illness in an urban slum in Dhaka, Bangladesh, during active surveillance in 2001. HMPV was the most common single virus identified among febrile children and appears to contribute to the high rates of illness in this population.     

Hospitalization rates for human metapneumovirus infection among 0- to 3-year-olds in Gipuzkoa (Basque Country), Spain

Numerous studies have been published on human metapneumovirus (HMPV) infection, but few have been population based. The main aim of this study was to estimate the incidence rate of hospitalization for community-acquired HMPV infection in infants and children aged <3 years. Between July 2004 and June 2007, 796 episodes (742 patients) of community-acquired acute respiratory infection were hospitalized. HMPV was detected in 90 episodes (11.3%). Fifty-nine episodes occurred in infants aged <1 year. The mean length of hospital stay was 6.2 days (range 2-31 days). Thirteen children required admission to the intensive care unit. Viral co-infections were detected in 46 episodes (51.1%). The incidence rate of hospitalization per 1000 inhabitants was 2.6 (95% CI 2.1-3.2), lower than that for respiratory syncytial virus, but higher than that observed for the influenza and parainfluenza viruses. HMPV is a major respiratory pathogen that leads to a high hospitalization rate.     

上海市松江区成人严重急性呼吸道感染住院病例流行病学特征分析

目的 了解上海市松江区成人严重急性呼吸道感染(severe acute respiratory infection,SARI)住院病例的流行病学特征及病原谱,探索新发传染病症状监测工作模式。方法 收集松江区某监测哨点医院2017年1月—2018年3月372例成人SARI住院病例监测资料,按照是否感染流感病毒,将病例分为流感组与非流感组,对流行病学及病原学特征等情况进行分析性描述。结果 共纳入372例SARI住院病例,SARI病例住院率4.15%,有夏季峰和冬季峰。发热、咳嗽、咳痰等是SARI住院病例最常见的临床症状,肺炎是最常见的并发症(48.66%),所有病例均未接种肺炎疫苗;流感组SARI病例数80例,流感病毒检测阳性率21.5%,其中甲型流感病毒占优势(56.25%);非流感组中其他病原体检出率为16.13%,以人肠病毒/鼻病毒的检出率最高(28.3%)。老年人在流感组中占比较高,差异有统计学意义(χ²=15.68,P<0.05);流感组的抗生素使用率较非流感组高,差异有统计学意义(χ²=27.73,P<0.05),非流感组呼吸衰竭的发生率较流感组高,差异有统计学意义(χ²=7.829,P<0.05)。结论 成人SARI病例监测的开展不仅是对新发传染病症状监测模式的探索实践,也对了解成人严重急性呼吸道感染的流行病学及病原学特征具有重要意义,建议提高老年人肺炎疫苗接种率以及流感病人临床抗病毒药物的使用。