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Respiratory Syncytial Virus (respiratory + syncytial_virus)
Kinds of Respiratory Syncytial Virus Terms modified by Respiratory Syncytial Virus Selected AbstractsRecent advances in the management and prophylaxis of respiratory syncytial virus infectionACTA PAEDIATRICA, Issue 2001A Greenough Respiratory syncytial virus (RSV) infection is an important cause of morbidity, particularly in prematurely born infants who have had chronic lung disease. Current therapy is essentially supportive. Overall, the results of randomized trials do not support the use of bronchodilators, corticosteroids or Ribavirin. Nitric oxide and exogenous surfactant may improve the respiratory status of those infants who require ventilatory support. Nosocomial infection can be reduced by appropriate handwashing. There is no safe and effective vaccine for use in infants. Immunoprophylaxis reduces hospitalization and requirement for intensive care. Palivizumab, a humanized monoclonal antibody, is preferred to RSV immune globulin as the immunoprophylactic agent. Immunoprophylaxis should be reserved for infants at highest risk of severe respiratory syncytial virus infection, if this strategy is to be used most cost-effectively. [source] Respiratory syncytial virus and human rhinoviruses are the major causes of severe lower respiratory tract infections in KuwaitJOURNAL OF MEDICAL VIROLOGY, Issue 8 2010M. Khadadah Abstract Respiratory infections are very common in Kuwait, yet little is known about the cause of severe lower respiratory tract infections. This study was designed to investigate the viral cause of lower respiratory tract infections using sensitive molecular methods. PCR was applied to investigate 10 respiratory viruses in respiratory samples from 1,014 patients aged between 3 days to 76 years with acute lower respiratory tract infections. Of the 1,014 patients with lower respiratory tract infections, 288 (28.4%) had a viral infection. One hundred fifty-five (53.8%) presented with bronchiolitis, 100 (43.7%) with pneumonia, and 33 (11.5%) with croup. One hundred six (36.8%) and 99 (34.4%) patients had evidence of respiratory syncytial virus and human rhinoviruses infections, respectively. Adenoviruses were detected in 44 (15.2%) patients, while influenza A virus in 21 (7.3%) patients. The majority of respiratory syncytial virus infections (84%) were among patients aged <1 year. Similarly, of the 99 patients infected by human rhinoviruses, 50 (50.5%) were also among this age group. In contrast, most of influenza A virus infections, 12 of 21 (57.1%), were among patients aged over 16 years. Parainfluenza virus-2 and human coronaviruses were not detected in any of the patients' samples. Over the 3-year period, most of the hospitalized patients were seen during the autumn and winter months from October through March. These data show that respiratory syncytial virus and human rhinoviruses may be the major causes of lower respiratory tract infections in children admitted to hospital in Kuwait. J. Med. Virol. 82:1462,1467, 2010. © 2010 Wiley-Liss, Inc. [source] Viral respiratory infections in hospitalized and community control children in Alaska,,JOURNAL OF MEDICAL VIROLOGY, Issue 7 2010Rosalyn J. Singleton Abstract Respiratory syncytial virus (RSV) in Alaska Native children from the Yukon Kuskokwim (YK) Delta is associated with a hospitalization rate five times higher than that reported for the general US child population. The role of other viral respiratory pathogens has not been studied in this population. YK Delta children <3 years of age hospitalized with respiratory infections and same aged community control children were prospectively enrolled between October 2005 and September 2007. Polymerase chain reaction detection of viruses was performed on nasopharyngeal samples. Characteristics of hospitalized and asymptomatic control children were analyzed. From October 2005 to September 2007, 440 hospitalized and 425 control children were analyzed. Respiratory viruses were detected in 90% (395) of hospitalized children: 194 (44%) rhinovirus, 131 (30%) adenovirus, 102 (23%) RSV, 77 (18%) para influenza viruses (PIV), 66 (15%) human metapneumovirus (hMPV), 23 (5%) influenza, and 25 (6%) coronavirus. Fifty-two percent (221) of control children had a virus detected, most commonly rhinovirus (33%), and adenovirus (16%). RSV, PIV, hMPV, and influenza were significantly more common in hospitalized cases than control children, but rhinovirus, adenovirus, and coronavirus were not. RSV and hMPV were associated with higher severity of illness. In this study, RSV remains the most important virus associated with respiratory hospitalization, although hMPV and PIV were also common. RSV and hMPV were associated with more severe illness. Rhinovirus and adenovirus were detected in two-thirds of hospitalized children, but their frequent detection in control children made their role in respiratory hospitalization uncertain. J. Med. Virol. 82:1282,1290, 2010. © 2010 Wiley-Liss, Inc. [source] Distinct patterns of evolution between respiratory syncytial virus subgroups A and B From New Zealand isolates collected over thirty-seven years,JOURNAL OF MEDICAL VIROLOGY, Issue 10 2006James W. Matheson Abstract Respiratory syncytial virus (RSV) is the most important cause of viral lower respiratory tract infections in infants and children worldwide. In New Zealand, infants with RSV disease are hospitalized at a higher rate than other industrialized countries, without a proportionate increase in known risk factors. The molecular epidemiology of RSV in New Zealand has never been described. Therefore, we analyzed viral attachment glycoprotein (G) gene sequences from 106 RSV subgroup A isolates collected in New Zealand between 1967 and 2003, and 38 subgroup B viruses collected between 1984 and 2004. Subgroup A and B sequences were aligned separately, and compared to sequences of viruses isolated from other countries during a similar period. Genotyping and clustering analyses showed RSV in New Zealand is similar and temporally related to viruses found in other countries. By quantifying temporal clustering, we found subgroup B viruses clustered more strongly than subgroup A viruses. RSV B sequences displayed more variability in stop codon usage and predicted protein length, and had a higher degree of predicted O-glycosylation site changes than RSV A. The mutation rate calculated for the RSV B G gene was significantly higher than for RSV A. Together, these data reveal that RSV subgroups exhibit different patterns of evolution, with subgroup B viruses evolving faster than A. J. Med. Virol. 78:1354,1364, 2006. © 2006 Wiley-Liss, Inc. [source] Melatonin decreases TLR3-mediated inflammatory factor expression via inhibition of NF-,B activation in respiratory syncytial virus-infected RAW264.7 macrophagesJOURNAL OF PINEAL RESEARCH, Issue 1 2008Sheng-Hai Huang Abstract:, Double-stranded (ds) RNA has been identified as a ligand for Toll-like receptor 3 (TLR3). Respiratory syncytial virus (RSV), a single-stranded RNA virus and a major respiratory pathogen and pneumovirus in human infants pathogenesis of which relies on early inflammatory and immune events of the host in response to RSV, could be recognized by TLR3 sensing viral dsRNA produced during replication. The downstream signaling pathway from TLR3 leads to activation of IFN regulatory factor (IRF)-3 and/or NF-,B and subsequent expression of numerous proinflammatory factors. Melatonin (MT) is an effective regulator of the immune system. To determine the molecular mechanisms responsible for the suppressive effect of MT on RSV infection, we analyzed signaling molecules involved in the TLR3-mediated activation of inflammatory factors in macrophages infected with RSV and the modulatory role of MT on these mediators. We report that RSV infection of RAW264.7 macrophages time-dependently stimulate the rapid activation of TLR3 and NF-,B, as well as subsequent NF-,B-dependent gene expression such as those encoding TNF-, and inducible nitric oxide synthase. Moreover, we demonstrate that MT decreased TLR3-mediated downstream gene expression in RSV-infected macrophages in a dose- and time-dependent manner, and that MT inhibition of NF-,B activity seemed to be the key event required to explain the reduction in inflammatory gene expression caused by MT. But MT did not influence TLR3 at either the protein or mRNA level or MyD88 transcription. These results could be related to the beneficial immunoregulatory role of MT in RSV-infected macrophages and address the possible therapeutic potential of this indoleamine in human RSV diseases. [source] Relationships among specific viral pathogens, virus-induced interleukin-8, and respiratory symptoms in infancyPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 6 2002James E. Gern Both virus-mediated damage to airway tissues and induction of pro-inflammatory cytokines such as interleukin-8 (IL-8) could contribute to symptom severity during viral respiratory infections in children. To test the hypothesis that IL-8 contributes to the pathogenesis of respiratory symptoms during naturally acquired respiratory viral infections in children, nasal wash samples collected from infants with acute viral infections (n = 198) or from healthy uninfected infants (n = 31) were analysed for IL-8. Nasal wash IL-8 was positively related to age in uninfected children (rs = 0.36, p,<,0.05). Respiratory syncytial virus (RSV) infection caused more severe respiratory symptoms compared to infections with influenza A, parainfluenza viruses, or rhinoviruses. In addition, RSV, parainfluenza and rhinovirus infections increased levels of IL-8 in nasal lavage fluid, and there were some differences in the ability of the viruses to induce IL-8 production (RSV>influenza, p,<,0.05). Finally, there were significant correlations between nasal wash IL-8 levels and symptom scores during infections with rhinovirus (rs = 0.56, p,<,0.001) or influenza A (rs = 0.45, p,<,0.05), but not with parainfluenza virus or RSV. These findings provide evidence of a close relationship between the generation of IL-8 and symptoms during acute community-acquired infections with rhinovirus or influenza A. In contrast, for RSV and parainfluenza infections, factors in addition to IL-8 production appear to contribute to the generation of clinical symptoms. [source] Inhaled corticosteroids during and after respiratory syncytial virus-bronchiolitis may decrease subsequent asthmaPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 3 2000Merja Kajosaari Respiratory syncytial virus (RSV) bronchiolitis in infancy can lead to bronchial hyper-reactivity or recurrent obstructive bronchitis. The aim of the present study was to determine whether the type of treatment has an influence on respiratory status after RSV bronchiolitis. The study involved 117 infants (mean age 2.6 months), who needed hospital treatment because of RSV bronchiolitis. The patients were divided randomly into three groups. All received the same symptomatic treatment. Group I children received symptomatic treatment only, group II children were treated for 7 days with inhaled budesonide, 500 µg three times per day, administered via a nebulizer. Group III children received nebulized budesonide, 500 µg twice per day for two months. Follow-up consisted of out-patient check-ups 2 and 6 months after the infection, and telephone contact two years after the infection. Statistically significant differences were seen between the groups. In group I 37% of the children had asthma, in group II 18%, and in group III 12%. According to the present study it seems that inhaled corticosteroid treatment during and after the acute phase of infant RSV bronchiolitis may have a beneficial effect on subsequent bronchial wheezing tendency. [source] Leukotriene synthesis during respiratory syncytial virus bronchiolitis: Influence of age and atopy,PEDIATRIC PULMONOLOGY, Issue 4 2005Giovanni Piedimonte MD Abstract Respiratory syncytial virus (RSV) infection is the most common cause of bronchiolitis in infants and an important risk factor for the development of recurrent wheezing and asthma. Cysteinyl leukotrienes were implicated in the pathophysiology of these diseases, and are being targeted for their diagnosis and therapy. We measured urinary leukotriene E4 (LTE4) in infants with RSV bronchiolitis in comparison with controls without respiratory infection, and investigated whether medical and family history, age, and passive exposure to tobacco smoke are related to urinary leukotriene excretion. We studied 33 infants with bronchiolitis and 25 controls, 1,12 months of age. Demographic and historical data were obtained from informed-consent forms and questionnaires completed by the parents. RSV was detected in nasal secretions by enzyme-linked immunoassay. Urine samples were collected on day of admission and were analyzed for LTE4 with an enzyme-linked immunoassay. Urinary LTE4 was 8-fold higher in infants with bronchiolitis than in controls. Leukotriene excretion was significantly higher in infected infants <6 months of age with a medical history of eczema or dry cough and/or family history of asthma. Multivariate analysis revealed that eczema and dry cough are independently associated with high LTE4 excretion during bronchiolitis. Exposure to tobacco smoke did not affect urinary LTE4. Our study shows that leukotriene synthesis during bronchiolitis is particularly elevated in younger infants with an atopic/asthmatic background. Urinary LTE4 may become a valuable, noninvasive marker for the identification of patients who will benefit most from therapy with leukotriene modifiers for management of bronchiolitis. Pediatr Pulmonol. © 2005 Wiley-Liss, Inc. [source] The interaction of neutrophils with respiratory epithelial cells in viral infectionRESPIROLOGY, Issue 1 2000Shan-Ze Wang Abstract: Viral respiratory infection is very common. Respiratory syncytial virus (RSV) infects almost all children during the first 2 years of life. Respiratory syncytial virus is the most frequent cause of bronchiolitis, which is strongly linked with asthma. However, the pathophysiology of RSV bronchiolitis is unclear. Neutrophils are the predominant airway leucocytes in RSV bronchiolitis and other viral infections. Neutrophils and their products are likely to play an important role in viral infection. Current evidence indicates that: (i) viral infection of epithelial cells increases the production of neutrophil chemoattractants or chemokines, which induce neutrophil migration into the inflammatory sites; (ii) the expression of adhesion molecules on neutrophils and epithelial cells is up-regulated in viral infection, and neutrophil-epithelial adhesion is increased; (iii) neutrophils augment epithelial damage and detachment induced by viral infection and contribute to the pathophysiology of viral disease; (iv) neutrophil apoptosis is up-regulated in RSV infection, which may be an in vivo mechanism to limit neutrophil-induced epithelial damage; (v) inhibitors of chemokines, adhesion molecules or neutrophil proteases may be useful in prevention of neutrophil-induced epithelial damage. In conclusion, neutrophils play an important role in viral infection, and intervention to prevent neutrophil-induced epithelial damage may be a potential clinical therapy. [source] Binding and entry of respiratory syncytial virus into host cells and initiation of the innate immune responseCELLULAR MICROBIOLOGY, Issue 10 2003James Harris Summary Respiratory syncytial virus (RSV) is the most common cause of severe lower respiratory tract infection in infants and the elderly. There is currently no effective antiviral treatment for the infection, but advances in our understanding of RSV uptake, especially the role of surfactant proteins, the attachment protein G and the fusion protein F, as well as the post-binding events, have revealed potential targets for new therapies and vaccine development. RSV infection triggers an intense inflammatory response, mediated initially by the infected airway epithelial cells and antigen-presenting cells. Humoral and cell-mediated immune responses are important in controlling the extent of infection and promoting viral clearance. The initial innate immune response may play a critical role by influencing the subsequent adaptive response generated. This review summarizes our current understanding of RSV binding and uptake in mammalian cells and how these initial interactions influence the subsequent innate immune response generated. [source] Respiratory syncytial virus (RSV) bronchiolitis and excessive thrombocytosisACTA PAEDIATRICA, Issue 4 2010I Mammas No abstract is available for this article. [source] Multiple viral respiratory pathogens in children with bronchiolitisACTA PAEDIATRICA, Issue 1 2009Hilary E Stempel Abstract Aim: The aim of the study was to describe the frequency of viral pathogens and relative frequency of co-infections in nasal specimens obtained from young children with bronchiolitis receiving care at a children's hospital. Methods: We conducted a study of nasal wash specimens using real-time PCR and fluorescent-antibody assay results from children less than two with an ICD-9-CM code for bronchiolitis. All specimens were collected for clinical care at Children's Hospital in Seattle, WA, USA, during the respiratory season from October 2003 to April 2004. Results: Viruses were detected in 168 (93%) of the 180 children with bronchiolitis. A single virus was identified in 127 (71%) children and multiple viruses in 41 (23%). Respiratory syncytial virus (RSV) was the most common virus detected (77%), followed by adenovirus (15%), human metapneumovirus (11%), coronavirus (8%), parainfluenza (6%) and influenza (1%). Of the 139 samples with RSV detected, 34 (24%) were co-infected with another viral pathogen. Conclusion: Molecular diagnostic techniques identified a high frequency of viruses and viral co-infections among children evaluated for bronchiolitis. Further study of the role of viral pathogens other than RSV and co-infections with RSV in children with bronchiolitis appears warranted. [source] Serum concentrations of interferon-, and intercellular adhesion molecule-1 eight years after an early respiratory syncytial virus infectionCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2005H. Juntti Summary Background Respiratory syncytial virus (RSV) infection may influence the development of recurrent wheezing and atopy, but the mechanisms are unclear. Objective The purpose was to evaluate serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), CD14, IgE, IL-5 and IFN-, in children 6,10 years after an RSV infection and their correlation with subsequent asthma and atopy. Methods Fifty-one subjects admitted to hospital for RSV infection during the first year of life and controls matched for birth date and sex underwent clinical examinations including lung function, skin prick and blood tests. Results The RSV subjects had significantly higher serum concentrations of IFN-, and sICAM-1 than the controls (for IFN-, 224.9 pg/mL (standard deviation (SD) 271.3) vs. 187.1 pg/mL (372.9), difference 37.8 pg/mL, 95% confidence interval (CI) ,90.3 to 166.0, P=0.05; for sICAM-1 170.2 ng/mL (SD 63) vs. 147.8 ng/mL (SD 57), difference 22.4 ng/mL, 95% CI ,1.4 to 46.1, P=0.04). The RSV subjects with asthma had significantly higher concentrations of IFN-, than the controls with asthma, and the RSV subjects with wheezing during the previous 12 months had significantly higher concentrations of both IFN-, and sICAM-1 than the controls with wheezing. Conclusions Children hospitalized for RSV infection in infancy still differ in IFN-, and sICAM-1 production 6,10 years after the infection. The data suggest that the pathomechanism of asthma and wheezing after an early RSV infection may be different from that of children without an early RSV infection. [source] Respiratory syncytial virus and neutrophil activationCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005E. L. Bataki Summary Respiratory syncytial virus infects almost all children by 2 years of age. Neutrophils are the predominant airway leucocytes in RSV bronchiolitis and they are activated in the presence of infection. However it is not clear whether RSV can directly signal to activate neutrophil cytotoxic function. To investigate this we have used a preparation of RSV washed using a new centrifugal diafiltration method to rapidly remove inflammatory molecules produced by the epithelial cells used to propagate the RSV stock. Human neutrophils were isolated from peripheral blood and activated with either the unwashed crude RSV preparations or the purified intact RSV. Neutrophils were also challenged with purified RSV G-glycoprotein. The effect of challenging human neutrophils with these preparations of intact RSV, or the RSV G-glycoprotein, was assessed by measuring the cell surface expression of CD11b and CD18b, the phagocytic oxidative burst, and intracellular release of calcium pools. Neutrophils challenged with the washed RSV exhibited significantly lower activation of surface marker expression (P < 0·001) and oxidative burst (P < 0·001) than those challenged with unwashed virus or with virus free supernatant. There was no increase in intracellular calcium release on exposure to the washed RSV. Purified G glycoprotein did not stimulate neutrophils, whilst the use of a blocking antibody to the F protein did not prevent unwashed RSV from activating cytotoxic responses. These results suggest that neutrophils have no innate signalling system that recognizes RSV but they are activated at sites of RSV infection as a result of the cytokines and inflammatory molecules released by virally infected cells. [source] Influenza A in Young Children with Suspected Respiratory Syncytial Virus InfectionACADEMIC EMERGENCY MEDICINE, Issue 12 2003Marla J. Friedman DO Objectives: To determine the prevalence of influenza A in young children suspected of having respiratory syncytial virus (RSV) infection and to compare the clinical presentation of these patients with those who have proven RSV infection. Methods: Children younger than or at 36 months of age who presented to a pediatric emergency department (ED) with suspected RSV infection during the influenza A season of 2001,2002 were eligible. Eligible children had an RSV antigen test ordered as part of their initial clinical management. A consecutive sample of children was enrolled for prospective observational analysis. The main outcome measure was the prevalence of influenza A in young children with suspected RSV infection. The secondary outcome measure was a comparison of the clinical presentations, of the two groups. Results: During the study period, 420 patients presented for evaluation of respiratory illness. RSV tests were ordered on 251 patients. Of 197 eligible patients, 124 (63%) tested positive for RSV and 33 (17%) for influenza A. Influenza A patients were more likely to have temperatures at or above 39°C than RSV patients (36% vs. 15%; p = 0.01). RSV patients were more tachypneic (54 vs. 43 breaths/minute; p < 0.0001) and more often had wheezing (90% vs. 8%; p < 0.0001). Twenty influenza patients (61%) were hospitalized. Conclusions: This study found a high prevalence of influenza A in young children suspected of having RSV infection. Clinicians should consider influenza A in young febrile children presenting with respiratory illnesses. [source] Functional impairment of cytotoxic T cells in the lung airways following respiratory virus infectionsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2006Simone Vallbracht Abstract We investigated the differentiation phenotype and function of virus-specific and non-specific CTL that were recruited to the lung parenchyma and the bronchoalveolar space after respiratory virus infections. Soon after virus elimination, we observed functional impairment of CTL isolated from the airways in their ability to produce IFN-, and TNF-, and to lyse target cells. Impaired cytotoxicity was due to a reduced content of granzyme B and a reduced ability to mobilize lytic granules. This impairment in effector functions (a) was largely restricted to CTL in the lung airways, (b) affected both CTL specific for the infecting virus as well as those that were recruited non-specifically to the inflamed lung, (c) was independent of contact between CTL and their specific viral antigen, (d) was not restricted to terminally differentiated CTL but also affected resting memory CTL and (e) could be elicited by both respiratory syncytial virus and influenza virus and thus seemed to be largely independent of the infecting virus. These observations suggest that functional impairment of antiviral T cells in the lung is not the consequence of a viral escape strategy. It may rather result from the particular milieu in the bronchoalveolar space and reflect a host mechanism to prevent excessive pulmonary inflammation. [source] Intranasal immunisation with inactivated RSV and bacterial adjuvants induces mucosal protection and abrogates eosinophilia upon challengeEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2006Nathalie Etchart Abstract We have previously shown that following intranasal exposure to influenza virus, specific plasma cells are generated in the nasal-associated lymphoid tissue (NALT) and maintained for the life of the animal. However, we also showed that following infection with respiratory syncytial virus (RSV), specific plasma cells are generated in the NALT but wane quickly and are not maintained even after challenge, even though RSV-specific serum antibody responses remain robust. Only infection with influenza virus generated sterilising immunity, implying a role for these long-lived plasma cells in protection. We show here that the RSV-specific IgA NALT plasma cell population and lung antibody levels can be substantially boosted, both at acute and memory time points, by intranasal immunisation with inactivated RSV (iRSV) in combination with bacterial outer membrane vesicles (OMV) compared to live RSV alone. Finally, challenge with live RSV showed that immunisation with iRSV and OMV protect against both virus replication in the lung and the eosinophil infiltrate generated by either live RSV or iRSV alone. These data show that immunisation with iRSV and OMV maintains a NALT RSV-specific plasma cell population and generates an efficient protective immune response following RSV infection. See accompanying commentary: http://dx.doi.org/10.1002/eji.200636118 [source] Role of influenza and other respiratory viruses in admissions of adults to Canadian hospitalsINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 1 2008Dena L. Schanzer Objective, We sought to estimate age-specific hospitalization rates attributed to influenza and other virus for adults. Methods, Admissions from Canada's national hospitalization database (Canadian Institute of Health Information), from 1994/95 to 1999/2000, were modeled as a function of proxy variables for influenza, respiratory syncytial virus (RSV) and other viral activity, seasonality and trend using a Poisson regression model and stratified by age group. Results, The average annual influenza-attributed hospitalization rate for all adults, 20 years of age or older, over the study period, which included three severe seasons, was an estimated 65/100 000 population (95% CI 63,67). Among persons aged 65 and over, 270,340 admissions per 100 000 population per year were attributed to influenza, while 30,110, 60,90 and 130,350 per 100 000 were attributed to RSV, parainfluenza (PIV) and other respiratory viruses, respectively. Although marked season-to-season variation in age-specific hospitalization rates attributable to influenza was observed in persons 50 years of age and older, increasing risk with age was preserved at all time periods. Conclusions, Influenza, RSV, PIV and other respiratory viruses were all associated with morbidity requiring hospitalization, while influenza was responsible for peak respiratory admissions. The burden of health care utilization associated with respiratory viruses is appreciable beginning in the sixth decade and increases significantly with age. [source] Inhalation efficacy of RFI-641 in an African green monkey model of RSV infectionJOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2003W.J. Weiss Abstract: Human respiratory syncytial virus (RSV) is a major cause of acute upper and lower respiratory tract infections. RFI-641 is a novel RSV fusion inhibitor with potent in vitro activity. In vivo efficacy of RFI was determined in an African green monkey model of RSV infection involving prophylactic and therapeutic administration by inhalation exposure. Inhalation was with an RFI-641 nebulizer reservoir concentration of 15 mg/ml for 15 minutes (short exposure) or 2 hours (long exposure). Efficacy and RFI-641 exposure was determined by collection of throat swabs, nasal washes and bronchial alveolar lavage (BAL) on selected days. The short-exposure group (15 minutes) exhibited no effect on the nasal, throat or BAL samples. The throat and nasal samples for the long-exposure group failed to show a consistent reduction in viral titers. RFI-641 2 hours exposure-treated monkeys showed a statistically significantly log reduction for BAL samples of 0.73,1.34 PFU/ml (P -value 0.003) over all the sampling days. Analysis indicates that the long-exposure group titer was lower than the control titer on day 7 and when averaged across days. The results of this study demonstrate the ability of RFI-641 to reduce the viral load of RSV after inhalation exposure in the primate model of respiratory infection. [source] Respiratory syncytial virus and human rhinoviruses are the major causes of severe lower respiratory tract infections in KuwaitJOURNAL OF MEDICAL VIROLOGY, Issue 8 2010M. Khadadah Abstract Respiratory infections are very common in Kuwait, yet little is known about the cause of severe lower respiratory tract infections. This study was designed to investigate the viral cause of lower respiratory tract infections using sensitive molecular methods. PCR was applied to investigate 10 respiratory viruses in respiratory samples from 1,014 patients aged between 3 days to 76 years with acute lower respiratory tract infections. Of the 1,014 patients with lower respiratory tract infections, 288 (28.4%) had a viral infection. One hundred fifty-five (53.8%) presented with bronchiolitis, 100 (43.7%) with pneumonia, and 33 (11.5%) with croup. One hundred six (36.8%) and 99 (34.4%) patients had evidence of respiratory syncytial virus and human rhinoviruses infections, respectively. Adenoviruses were detected in 44 (15.2%) patients, while influenza A virus in 21 (7.3%) patients. The majority of respiratory syncytial virus infections (84%) were among patients aged <1 year. Similarly, of the 99 patients infected by human rhinoviruses, 50 (50.5%) were also among this age group. In contrast, most of influenza A virus infections, 12 of 21 (57.1%), were among patients aged over 16 years. Parainfluenza virus-2 and human coronaviruses were not detected in any of the patients' samples. Over the 3-year period, most of the hospitalized patients were seen during the autumn and winter months from October through March. These data show that respiratory syncytial virus and human rhinoviruses may be the major causes of lower respiratory tract infections in children admitted to hospital in Kuwait. J. Med. Virol. 82:1462,1467, 2010. © 2010 Wiley-Liss, Inc. [source] Detection of viruses identified recently in children with acute wheezingJOURNAL OF MEDICAL VIROLOGY, Issue 8 2007Ju-Young Chung Abstract The etiologic role of recently identified respiratory viruses for acute wheezing in children is not yet clear. The purpose of this study was to investigate the prevalence of recently identified viruses, including human metapneumovirus (hMPV), human bocavirus (hBoV), human coronavirus NL63 (hCoV-NL63), and human coronavirus HKU1 (hCoV-HKU1) in children with acute wheezing. Viral etiology was identified in 231 children hospitalized with acute wheezing, aged from 1 month to 5 years. Viral antigens for common respiratory viruses were detected by IFA or multiplex PCR. RT-PCR was used to detect respiratory rhinoviruses, hCoV-NL63, hCoV-HKU1, and hMPV. PCR assays for hBoV DNA were performed using the primer sets for noncapsid protein (NP1) and nonstructural protein (NS1) genes. Viruses were found in 61.5% (142/231) of the study population and a single virus was detected in 45.5% (105/231) of the study population. Rhinovirus (33.3%), human respiratory syncytial virus (hRSV; 13.8%), and hBoV (13.8%) were the most frequently detected viruses. hMPV and hCoV-NL63 were detected in 7.8% and 1.3% of wheezing children, respectively. HCoV-HKU1 was not detected. In 16.0% of the study population, more than one virus was detected. In children with acute wheezing, rhinovirus, hRSV, and hBoV were most frequently detected. Further studies including healthy control subjects are needed to define the clinical significance of hBoV in acute wheezing. J. Med. Virol. 79: 1238,1243, 2007. © 2007 Wiley-Liss, Inc. [source] Detection and typing by molecular techniques of respiratory viruses in children hospitalized for acute respiratory infection in Rome, ItalyJOURNAL OF MEDICAL VIROLOGY, Issue 4 2007Alessandra Pierangeli Abstract Detection of a broad number of respiratory viruses is not undertaken currently for the diagnosis of acute respiratory infection due to the large and always increasing list of pathogens involved. A 1-year study was undertaken on children hospitalized consecutively for acute respiratory infection in a Pediatric Department in Rome to characterize the viruses involved. Two hundred twenty-seven children were enrolled in the study with a diagnosis of asthma, bronchiolitis, bronchopneumonia, or laringo-tracheo bronchitis. A molecular approach was adopted using specific reverse transcription (RT)-PCR assays detecting 13 respiratory viruses including metapneumovirus (hMPV) and the novel coronaviruses NL63 and HKU1; most amplified fragments were sequenced to confirm positive results and differentiate the strain. Viral pathogens were detected in 97 samples (42.7%), with 4.8% of dual infections identified; respiratory syncytial virus (RSV) was detected in 17.2% of children, followed by rhinovirus (9.7%), parainfluenza virus type 3 (PIV3) (7.5%), and influenza type A (4.4%). Interestingly, more than half the patients (9/17) that have rhinovirus as the sole respiratory pathogen had pneumonia. HMPV infected children below 3 years in two peaks in March and June causing bronchiolitis and pneumonia. One case of NL63 infection is described, documenting NL63 circulation in central Italy. In conclusion, the use of a comprehensive number of PCR-based tests is recommended to define the burden of viral pathogens in patients with respiratory tract infection. J. Med. Virol. 79:463,468, 2007. © 2007 Wiley-Liss, Inc. [source] Impact of human metapneumovirus and human cytomegalovirus versus other respiratory viruses on the lower respiratory tract infections of lung transplant recipientsJOURNAL OF MEDICAL VIROLOGY, Issue 3 2006Giuseppe Gerna Abstract Viral respiratory tract infections in lung transplant recipients may be severe. During three consecutive winter-spring seasons, 49 symptomatic lung transplant recipients with suspected respiratory viral infection, and 26 asymptomatic patients were investigated for presence of respiratory viruses either in 56 nasopharyngeal aspirate or 72 bronchoalveolar lavage samples taken at different times after transplantation. On the whole, 1 asymptomatic (3.4%) and 28 symptomatic (57.1%) patients were positive for human metapneumovirus (hMPV, 4 patients), influenza virus A (3 patients), and B (2 patients), respiratory syncytial virus (2 patients), human coronavirus (2 patients), human parainfluenza virus (2 patients), rhinovirus (5 patients), while 4 patients were coinfected by 2 respiratory viruses, and 5 were infected sequentially by 2 or more respiratory viruses. In bronchoalveolar lavage samples, hMPV predominated by far over the other viruses, being responsible for 60% of positive specimens, whereas other viruses were present in nasopharyngeal aspirates at a comparable rate. RT-PCR (detecting 43 positive samples/128 examined) was largely superior to monoclonal antibodies (detecting 17 positive samples only). In addition, HCMV was detected in association with a respiratory virus in 4/18 HCMV-positive patients, and was found at a high concentration (>105 DNA copies/ml) in 3/16 (18.7%) patients with HCMV-positive bronchoalveolar lavage samples and pneumonia. Coinfections and sequential infections by HCMV and respiratory viruses were significantly more frequent in patients with acute rejection and steroid treatment. In conclusion: (i) about 50% of respiratory tract infections of lung transplant recipients were associated with one or more respiratory viruses; (ii) hMPV largely predominates in bronchoalveolar lavage of symptomatic lung transplant recipients, thus suggesting a causative role in lower respiratory tract infections; (iii) RT-PCR appears to be the method of choice for detection of respiratory viruses in lung transplant recipients, (iv) a high HCMV load in bronchoalveolar lavage is a risk factor for viral pneumonia, suggesting some measure of intervention for the control of viral infection. J. Med. Virol. 78:408,416, 2006. © 2006 Wiley-Liss, Inc. [source] A phylogenetic study of human respiratory syncytial viruses group A and B strains isolated in two cities in Japan from 1980,2002JOURNAL OF MEDICAL VIROLOGY, Issue 2 2005Yuki Kuroiwa Abstract The circulation pattern and genetic evolution of respiratory syncytial virus (RSV) in Japan were examined based on 109 RSV field strains isolated over 20 seasons (1980,2002) in two cities, Sapporo and Tokyo. The second hypervariable region of the large glycoprotein (G) gene was amplified by RT-PCR and the products sequenced directly. The nucleotide sequences were compared to those representatives of RSV genotypes identified previously. Japanese group A and B isolates clustered into five and four genotypes defined previously, respectively. Another one group A and one group B genotypes, which could not be assigned to previous genotypes, were also identified. Although different genotypes usually co-circulated in each season, the isolates in proximate seasons from two communities were usually located in the same branches. Moreover, the strains with genotypes defined previously were usually isolated at the same time as each reference strain of Western countries. Several mutant group B strains with 1,20 longer amino acid G proteins were newly identified in Sapporo. These findings suggest that Japanese RSV strains underwent geographical and also temporal clustering while participating in RSV genetic evolution in a global setting. In addition, Japanese strains, especially group B, might have evolved individually in each community, sometimes changing the length of the G protein. J. Med. Virol. 76:241,247, 2005. © 2005 Wiley-Liss, Inc. [source] A comparison of epidemiologic and immunologic features of bronchiolitis caused by influenza virus and respiratory syncytial virusJOURNAL OF MEDICAL VIROLOGY, Issue 2 2005Roberto P. Garofalo Abstract We studied epidemiologic and immunologic factors in infants with bronchiolitis caused by influenza virus. The proportion of these infants who were male and who had an immediate family member with a history of asthma was similar to that of a control group of infants with respiratory syncytial virus (RSV) bronchiolitis. In subjects with influenza virus infection, concentrations of the beta chemokine macrophage inflammatory protein-1alpha (MIP-1,), but not other beta chemokines, in nasopharyngeal secretions (NPS) were greater among infants with more severe, hypoxic bronchiolitis than in subjects with mild, nonhypoxic bronchiolitis, or upper respiratory tract infection alone. Quantities of MIP-1, were also correlated with lower values of oxygen saturation. These findings point out epidemiologic and immunologic similarities between bronchiolitis caused by influenza and RSV, and suggest that host factors are more important than the nature of the infecting virus in the development of severe forms of bronchiolitis caused by influenza and RSV. J. Med. Virol. 75:282,289, 2005. © 2004 Wiley-Liss, Inc. [source] Impact of human metapneumovirus in childhood: Comparison with respiratory syncytial virus and influenza viruses,JOURNAL OF MEDICAL VIROLOGY, Issue 1 2005Samantha Bosis Abstract This study evaluated the overall impact of human metapneumovirus (hMPV) infection in 1,505 children and their households, and compared it with infections due to respiratory syncytial virus (RSV) and influenza viruses. Nasopharyngeal swabs were used at enrollment to collect specimens for the detection of hMPV, RSV, and influenza virus RNA by reverse-transcriptase polymerase chain reaction (RT-PCR). hMPV was detected in 42 children (2.8%), RSV in 143 (9.5%; P,<,0.0001 vs. hMPV), and influenza viruses in 230 (15.3%; P,<,0.0001 vs. hMPV). Of the 42 hMPV-positive samples, one was also positive for RSV and six for influenza viruses, for a co-infection rate of 16.7%. Clinically, hMPV was identified only in patients with acute respiratory infection, whereas RSV and influenza viruses were also detected in patients with different clinical manifestations. Symptoms with statistically significant different proportions at presentation were fever (more frequent in the hMPV- and influenza-positive children) and wheezing with bronchiolitis or asthma exacerbation (more frequent among hMPV- and RSV-positive cases). The households of the hMPV- and the influenza-positive children had significantly more illnesses, needed significantly more medical visits, received more antipyretics, and missed significantly more work or school days than those of the RSV-positive children. Results show that hMPV is an emerging cause of acute respiratory infection in childhood, and may have a significant clinical and socioeconomic impact on children and their families. J. Med. Virol. 75:101,104, 2005. © 2005 Wiley-Liss, Inc. [source] Leucocyte populations in respiratory syncytial virus-induced bronchiolitisJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 2 2001PK Smith Objectives: To enumerate the cellular composition of the airways in infants with acute bronchiolitis. Methodology: Cells were obtained by airway lavage from the upper and lower airway and the peripheral blood of infants with respiratory syncytial virus (RSV)+ bronchiolitis, RSV, bronchiolitis and age-matched controls. Results: Neutrophils are the predominant cells present in the upper and lower airway. Neutrophils are present at a higher number/unit volume in the airway than in the peripheral blood. Conclusions: Neutrophils, being the dominant cellular infiltrate into the airway, are likely to contribute to the pathophysiology of bronchiolitis. Therapies targeted at limiting neutrophil influx or neutrophil-mediated damage in the airway may have a therapeutic role. [source] Recurrent wheezing after respiratory syncytial virus or non-respiratory syncytial virus bronchiolitis in infancy: a 3-year follow-upALLERGY, Issue 9 2009H. Valkonen Background:, Recent studies have suggested that rhinovirus-associated early wheezing is a greater risk factor for development of recurrent wheezing in children than is early wheezing associated with respiratory syncytial virus (RSV). We determined the development of recurrent wheezing in young children within 3 years after hospitalization for RSV or non-RSV bronchiolitis. Methods:, We identified retrospectively all children <2 years of age who were admitted to Turku University Hospital because of bronchiolitis in the months of August,December during 1988,2001. The primary outcome was recurrent wheezing that required long-term asthma medication. Data on asthma medications of the individual children were derived from the Social Insurance Institution of Finland. Results:, Within the first year after hospitalization, 36 of 217 (16.6%) children with non-RSV bronchiolitis developed recurrent wheezing, compared with five of 199 (2.5%) children with RSV bronchiolitis [relative risk (RR) 6.6; 95% confidence interval (CI) 2.6,16.5]. The rates of recurrent wheezing were significantly increased in the non-RSV group also within 2 years (RR 2.9; 95% CI 1.7,5.1) and 3 years (RR 3.4; 95% CI 2.0,5.7) after hospitalization. The increased risk of recurrent wheezing in children with non-RSV-associated bronchiolitis was observed both in boys and girls at all time points of the 3-year follow-up, and it was not explained by the age difference between the RSV and non-RSV groups or any confounding seasonal factors. Conclusion:, Children hospitalized with bronchiolitis caused by other viruses than RSV develop recurrent wheezing at substantially higher rates during a 3-year follow-up period than do children with RSV-induced bronchiolitis. [source] Ability of low-molecular-weight heparin to alleviate proteinuria by inhibiting respiratory syncytial virus infectionNEPHROLOGY, Issue 7 2008YANNAN GUO SUMMARY: Aim: Low-molecular-weight heparin (LMWH) is a negatively charged glycoprotein and has a very similar structure to that of cell surface heparin sulfate (HS). Thus, LMWH, an analog of HS, may inhibit positively charged respiratory syncytial virus (RSV) infection through cooperative electrostatic association. Methods: In this study, rats were respectively treated with 400 IU/kg LMWH before, during or after being inoculated with 6 × 106 plaque-forming unit (PFU) RSV. RSV and normal control groups were respectively inoculated by RSV and virus-free Dulbecco's modified Eagle's medium (DMEM). HeLa cells in vitro were pretreated with LMWH, elastase (ELA), heparinase (HpaIII) and protamine before being inoculated with 6 × 101 PFU RSV. RSV infectivity was determined by in situ hybridization and plaque assay. Results: After inoculation, the urinary protein excretion and serum parameters in LMWH-treated rats were significantly lower than those in the RSV group. No abnormalities of glomerular structure were observed in LMWH-treated groups whereas swelling and slight hypercellularity in minority glomeruli and foot process effacement were observed in the RSV group. RSV RNA of LMWH-treated rats had weaker expression than that of the RSV group. In vitro, RSV infection in RSV + LMWH, HpaIII + ELAI, protamine + ELAI, ELAI, HpaIII and protamine treatment cells were significantly lower than that of the RSV control, and that in RSV + LMWH was the least. There were no significant differences in RSV infection between ELAI + LMWH and RSV control. Conclusion: Our study confirmed that there is a correlation between RSV and proteinuria in rats. LMWH can alleviate proteinuria in rats through inhibiting RSV from binding with HS which plays an important role in the onset of RSV infection. [source] Suppression of IFN-gamma production in atopic group at the acute phase of RSV infectionPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2006Hideo Kaneko Several studies have suggested that respiratory syncytial virus (RSV) bronchiolitis induced the change of cytokine production profile in childhood. We sought to determine whether the RSV-induced cytokine production was affected by the patient's atopic background. We quantified interferon-gamma (IFN-gamma) and interleukin (IL)-4 in the supernatant of peripheral blood mononuclear cells (PBMCs) cultured for 24 h and in the presence of phytohemaglutinin (PHA), IL-12, or IL-18, from 14 infants who were divided into two groups, those who are non-atopic and an atopic group. In RSV-infected infants with atopic diseases, IFN-gamma production from IL-12- or especially IL-18-stimulated PBMCs was subtotally suppressed in the acute phase, whereas in RSV-infected infants without atopic diseases IFN-gamma production was not suppressed on acute phase. The IFN-gamma suppression observed in the atopic group is not caused by the immaturity of an infant's immune system since reduced IFN-gamma production to RSV is not observed in the infants of non-atopic group. IFN-gamma suppression in regard to RSV infection might be caused by some genetic factor involved in the development of atopic disease such as IL-18 signal cascade. 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