Retrospective comparison of respiratory syncytial virus and metapneumovirus clinical presentation in hospitalized children

Respiratory syncytial virus (RSV) and Human metapneumovirus (hMPV), members of Pneumoviridae family are common causes of acute respiratory tract infections (ARTI) among children. Study material includes routine nasopharyngeal samples obtained during 8-year period for hMPV and one single season for RSV in children hospitalized for ARTI between 0 and 15 years at the Center Hospitalier Universitaire (CHU) Saint Pierre in Brussels. Positive samples for RSV or hMPV identified by viral culture, lateral flow chromatography test for RSV or direct fluorescent assay for hMPV were selected retrospectively. Characteristics of children hospitalized for RSV or hMPV infections were compared. Children hospitalized for RSV infection were significantly younger and requiring more respiratory support, longer hospital stay and transfers in Pediatric intensive Care Units than those hospitalized for hMPV infection. Pneumonia diagnostic and antibiotics therapies were more significantly associated with hMPV infections. In conclusion, despite their genetic similarities, RSV, and hMPV present epidemiological and clinical differences in pediatric infections. Our results should be confirmed prospectively.     

Absence of human metapneumovirus co-infection in cases of severe respiratory syncytial virus infection

It has been suggested that co-infection of human metapneumovirus (hMPV) in severe respiratory syncytial (RSV) virus bronchiolitis is very common. To evaluate the epidemiology of hMPV co-infection in children with severe lower respiratory tract infection caused by RSV virus. This was an observational cohort study in which hMPV and RSV viral load was measured by RT-PCR in tracheal specimens from the target population. hMPV could not be detected in any of the 30 mechanically ventilated children with RSV lower respiratory tract infection. Our study suggests that hMPV co-infection is not very common in severe RSV lower respiratory tract infection.     

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.     

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.     

Human metapneumovirus and respiratory syncytial virus infections in older children with cystic fibrosis

BACKGROUND: Human metapneumovirus (hMPV) has been isolated from children with acute respiratory infection worldwide. Its epidemiology remains to be defined in children with cystic fibrosis (CF). We describe the epidemiology and clinical impact of hMPV in CF children and compared it to respiratory syncytial virus (RSV). METHODS: CF children ages 7-18 years were studied prospectively during the 1998 -1999 RSV season. Nasopharyngeal specimens were collected during acute respiratory illnesses and tested for respiratory viruses. Blood specimens were drawn early, mid, and end of the RSV season, and tested for serological evidence of hMPV and RSV infections. Rates of lower respiratory tract illnesses (LRTI) and hospitalizations for pulmonary exacerbations were compared during the time intervals they developed serological evidence of infection to their non-infection intervals. RESULTS: Six of 44 CF children had a virus positive respiratory illness in 56 LTRI events and 18 hospitalizations. Serological evidence of hMPV and RSV infections occurred in 16 and 20 CF children, respectively; 8 had infections with both viruses. A greater proportion of CF children had >or=1 LRTI during their infection intervals compared to their non-infection intervals (13/25 vs. 5/25; P=0.03). A trend for higher rates of LRTI was observed in the infection intervals compared to non-infection intervals (9.5 +/- 11.0 vs. 4.2 +/- 9.9 per 1,000 child-days; P=0.06), and it was significantly greater with a more conservative estimate (one event per child per interval; 7.4 +/- 7.7 vs. 2.6 +/- 5.4 per 1,000 child-days; P 相似文献   

Human metapneumovirus: a new pathogen in children and adults

In 2001, human metapneumovirus (hMPV) was discovered in young children with respiratory tract infection of unknown origin. In the two years since its discovery the dinical characteristics of this new virus have been darified. In children, especially those younger than one year of age, hMPV is responsible for 5 to 10% of respiratory tract infections requiring hospitalisation; its clinical course is somewhat milder, but otherwise indistinguishable from respiratory syncytial virus (RSV) infection. Human MPV can also be found in adults, in influenza-like illnesses, but also as a cause of pneumonia. Especially in the latter cases immunosuppressive conditions may be present.     

Human metapneumovirus bronchiolitis in infancy is an important risk factor for asthma at age 5

BACKGROUND: Human metapneumovirus (hMPV) infection plays an important role in the pediatric respiratory infections. However, little is known about the relationship between hMPV-bronchiolitis and the development of subsequent wheezing. The aim of this study was to evaluate the outcome at third to fifth year after admission for hMPV-bronchiolitis and to compare it with children admitted for respiratory syncytial virus (RSV)-bronchiolitis and with children without lower respiratory disease in the first 2 years of life. METHODS: We studied 55 children (23 hMPV and 32 RSV acute bronchiolitis) aged 3-5 years and hospitalized during the seasons 2000-2005. Thirty-eight children admitted due to acute rotavirus gastroenteritis in the same seasons, and without bronchiolitis during infancy, were also analyzed. Clinical data were collected through structured clinical interviews at the follow-up visit. Skin prick tests to food and inhaled allergens were performed. RESULTS: Asthma was significantly more frequent in children with hMPV-bronchiolitis (odds ratio (OR) = 5.21), RSV-bronchiolitis (OR = 4.68), allergic rhinitis (OR = 1.7), and siblings with atopy (OR = 1.75). In the multivariate analyses, hMPV was the most important risk factor for asthma in preschool years (OR = 15.9), followed by RSV-bronchiolitis (OR = 10.1) and allergic rhinitis (OR = 4.9).No differences were found with respect to allergic rhinitis, atopic dermatitis, food allergy, proportion of positive prick tests, family history of atopy, and asthma. CONCLUSIONS: hMPV-bronchiolitis in infancy was strongly associated with asthma as well as other forms of bronchial obstructive disease at third and fifth year of life. This association is, at least, as strong as the association observed with RSV infections.     

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.     

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.     

Systematic literature review of the signs and symptoms of respiratory syncytial virus

Respiratory syncytial virus (RSV) is responsible for over 30 million lower respiratory tract infections (LRTIs) and 3 million hospitalizations worldwide each year. Despite the risk RSV poses to young children, older adults, and individuals with comorbidities or suppressed immunity, there is limited understanding of RSV symptom presentation across these at-risk groups, and there is no vaccine for RSV. We conducted two systematic literature reviews (SLRs) of studies that document signs and symptoms (S&S) of RSV in (1) children aged ≤5 years and (2) immunocompromised adolescents and adults, and adults at high risk for severe RSV due to age or comorbidities. Symptom duration and hospital length of stay (LOS) were explored. Electronic database searches were performed following PRISMA guidelines. Studies captured RSV S&S across community and hospital settings. Clinicians and caregivers reported (n = 25 studies) nasal discharge/congestion, cough, shortness of breath, feeding abnormalities, and fever in ≥40% of children across studies and settings. Median hospital stays for children ranged from 2 days in the United States to 7.5 days in China. High-risk adults with RSV (n = 6 studies) commonly (≥40% of adults) reported cough, sputum, dyspnea, and fever/feverishness. Median length of hospital stay in adults ranged from 6 to 15 days across studies. Caregivers and clinicians reported similar RSV S&S in young children, including upper and lower respiratory and systemic symptoms. In high-risk and immunocompromised adults, the most frequent (in multiple publications) and commonly reported RSV S&S were primarily LRTI symptoms. RSV symptoms could last for weeks and are variable based on geography.     

The impact of infection with human metapneumovirus and other respiratory viruses in young infants and children at high risk for severe pulmonary disease

We conducted a prospective, observational study to characterize the clinical manifestations of respiratory infections caused by human metapneumovirus (hMPV) and other viruses in 194 premature infants and young children with chronic lung disease or congenital heart disease in Buenos Aires. Children had 567 episodes of respiratory illness and were monitored until they were 2 years old or until the completion of the study. hMPV elicited 12 infections (2%) year-round; 30% were of moderate or greater severity. Human parainfluenza virus type 3 caused 24 infections (4%), and 5 (25%) of 20 lung infections led to hospitalization. Respiratory syncytial virus (RSV) caused 33 episodes--17% of infections and 32% of hospitalizations during the respiratory season. None of the 10 children infected with influenza virus had severe disease. The present study of at-risk children suggests that hMPV and influenza virus are infrequent agents of severe disease and highlights the need for preventive interventions against RSV in developing countries.     

Prevalence of respiratory syncytial virus infection in Italian infants hospitalized for acute lower respiratory tract infections,and association between respiratory syncytial virus infection risk factors and disease severity

This study was designed to collect data on the prevalence of respiratory syncytial virus (RSV) infection in Italy in infants hospitalized for lower respiratory tract infections, and to evaluate which of the recognized risk factors might be associated with disease severity. Thirty-two centers throughout Italy participated in the study. Over a 6-month period (November 1,1999 to April 30, 2000), we evaluated all children < 2 years of age hospitalized for lower respiratory tract infections. All subjects were tested for RSV within 24 hr of hospitalization by using an immuno-enzymatic diagnostic test (Abbott Testpack, RSV). Logistic regression was used to identify the factors that might be associated with more severe disease or could increase the likelihood of RSV positivity in hospitalized infants.Out of a total of 1,232 children enrolled, 40.6% were found to be RSV-positive (RSV+). The peak of the RSV epidemic occurred in February, while the lowest prevalence of RSV positivity was seen in November (P < 0.05). A high proportion of study subjects had low birth weight and low gestational age. The clinical diagnosis at hospitalization was bronchiolitis in 66.7%, pneumonia in 15.3%, and wheezy bronchitis in 18.1%. In the bronchiolitis group, a higher prevalence of RSV+ was found in patients with gestational age or= 36 weeks (P < 0.04). No differences were found in the proportion of RSV+ patients in the three gestational age subgroups with pneumonia and wheezy bronchitis (P > 0.05, each comparison). Independent of the clinical diagnosis at admission, RSV infection was associated with more severe respiratory impairment. Environmental smoke exposure was higher in subjects with bronchiolitis than in those with wheezy bronchitis (P < 0.04), and RSV+ was positively related with the birth order (P < 0.05). The presence of older siblings and birth order plays an important role in RSV infection.The collected data show that, in Italy, RSV is an important cause of lower respiratory tract infection in infants. Gestational age, birth order, birth weight, and exposure to tobacco smoke affected the prevalence and severity of RSV-related lower respiratory tract disease.     

Retrospective Serology Study of Respiratory Virus Infections in Captive Great Apes

Great apes are extremely sensitive to infections with human respiratory viruses. In this study, we retrospectively analyzed sera from captive chimpanzees, gorillas and orang-utans. More than 1000 sera (403 chimpanzee, 77 gorilla, and 535 orang-utan sera) were analyzed for antibodies to the human respiratory viruses RSV (respiratory syncytial virus, hMPV (human metapneumovirus), H1N1 and H3N2 influenza A viruses, and influenza B virus. In all ape species high seroprevalences were found for RSV, hMPV, and influenza B virus. A high percentage of captive chimpanzees also showed evidence of influenza A H1N1 infections, and had low levels of H3N2 antibodies, while in sera from gorillas and orang-utans antibody levels to influenza A and B viruses were much lower or practically absent. Transmission of respiratory viruses was examined in longitudinal sera of young chimpanzees, and in chimpanzee sera taken during health checks. In young animals isolated cases of influenza infections were monitored, but evidence was found for single introductions followed by a rapid dissemination of RSV and hMPV within the group. Implementation of strict guidelines for handling and housing of nonhuman primates was shown to be an efficient method to reduce the introduction of respiratory infections in colonies of captive animals. RSV seroprevalence rates of chimpanzees remained high, probably due to circulating virus in the chimpanzee colony.     

2665例急性上呼吸道感染患儿的病原学及临床特征

目的 分析急性上呼吸道感染儿童患者的病原学及临床特征。方法 以南方医科大学珠江医院2009年11月至2015年9月收治的2 665例急性上呼吸道感染儿童为研究对象,采用qRT-PCR方法检测临床上常见的8种呼吸道病毒(流感病毒、呼吸道合胞病毒、副流感病毒、腺病毒、人类博卡病毒、人类冠状病毒、人类偏肺病毒、鼻病毒)。结果 共检测患儿标本2 665份,其中阳性标本1 566份,总阳性率为58.8%。四个季节中8种呼吸道病毒检出率存在明显差异,并以春季最高,夏冬季次之,秋季最低。儿童呼吸道病毒感染率随着年龄增加而逐渐降低,并以0~1岁婴幼儿病毒检出率最高64.5%。男童呼吸道病毒感染率高于女童,住院患儿呼吸道病毒检出率高于门诊患儿。混合感染标本260份,占阳性标本数的16.6%,主要集中于0~3岁儿童患者标本中,并因季节而异,秋冬季节较少,而春夏季节较为普遍。咳嗽为呼吸道病毒感染的主要临床症状,咳痰和流涕次之,临床症状在8种呼吸道病毒感染患儿中存在差异。结论 本调查分析了急性上呼吸道感染患儿中8种常见呼吸道病毒的病原学及临床特征,为指导临床治疗及防控提供相关数据。     

Differential production of inflammatory cytokines in primary infection with human metapneumovirus and with other common respiratory viruses of infancy

Viral respiratory infections are the most frequent cause of hospital admission for infants and young children during winter. However, the mechanisms of illness that are associated with viral lower-respiratory-tract infection (LRI) are unclear. A widely accepted hypothesis attributes the pathogenesis of viral LRI in infants to the induction of innate inflammatory responses. This theory is supported by studies showing that Toll-like receptor 4 is activated by respiratory syncytial virus (RSV), leading to production of inflammatory cytokines. We prospectively examined previously naive infants in Buenos Aires, Argentina, who had either upper- or lower-respiratory-tract symptoms. Infection with human metapneumovirus (hMPV) was second only to RSV in frequency. Both viruses were associated with rhinorrhea, cough, and wheezing; however, hMPV elicited significantly lower levels of respiratory inflammatory cytokines than did RSV. Symptoms in infants infected with influenza virus were different from those in infants infected with RSV, but cytokine responses were similar. These findings suggest that hMPV and RSV either cause disease via different mechanisms or share a common mechanism that is distinct from innate immune activation.