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PubMed1999

Respiratory syncytial virus infection among young children with acute respiratory tract infection in Iraq.

The incidence of respiratory syncytial virus infection was assessed among 516 children under 5 years with acute respiratory infection and 57 control children free of respiratory infection to determine its relation to epidemiological variables. Respiratory syncytial virus was detected in 188 (37.6%) children with acute respiratory infection and in none of the control group. The infection was highest in those with severe acute respiratory infection, particularly severe bronchiolitis and pneumonia and it precipitated acute bronchial asthma in children over 2 years. The infection was most common in the first 6 months and both sexes were equally affected. Socioeconomic factors and crowding played no significant role in the incidence and spread of the infection. Breastfeeding had no clear protective effect against the infection.

Acute Disease↗
PubMed2001

[Relationship between respiratory syncytial virus subtype and clinical severity in bronchiolitis].

BACKGROUND: Respiratory syncytial virus (RSV) is the most frequently implicated agent in bronchiolitis. The virus presents two antigenic subtypes (A and B). The results of studies on the relationship between viral subtype and clinical severity are conflicting. PURPOSE: To evaluate whether the subtype of this virus constitutes an independent variable in the severity of clinical expression of RSV infection. PATIENTS AND METHODS: We prospectively studied previously healthy children aged less than 2 years admitted for RSV infection during an epidemic season. Clinical presentation and evolution, laboratory and radiological aspects were compared in subsets of children infected with RSV subtype A or B. Clinical severity parameters included score and duration of respiratory distress, oxygen requirements, admission to the intensive care unit, mechanical ventilation and length of hospital stay. RESULTS: Eighty-five patients were enrolled in the study (50 boys and 35 girls; mean age 4.8,4.3 months). Fifty-nine children were infected with RSV subtype A. No differences were found in age, sex or antecedents but children with subtype B were less likely to have been breast-fed. Clinical presentation and laboratory and radiological findings were similar in both groups. No statistically significant differences in clinical severity parameters were found between subsets A and B. Age less than 3 months was associated with greater duration of respiratory distress and longer hospital stay. CONCLUSION: The results do not support the hypothesis that subtype A infection is associated with more severe respiratory syncytial virus disease.

Bronchiolitis↗
PubMed2001

DNase treatment for atelectasis in infants with severe respiratory syncytial virus bronchiolitis.

Respiratory insufficiency due to respiratory syncytial virus (RSV) bronchiolitis is partly due to the abundance of thickened mucus and the inability to clear it from the airways. Mucus in RSV bronchiolitis contains necrotic inflammatory and epithelial cells. The viscoelastic properties of purulent airway secretions are largely due to the presence of highly polymerized deoxyribonucleic acid (DNA). Recombinant human deoxyribonuclease (rhDNase) is known to liquefy such mucus in patients with cystic fibrosis, whereas case reports described a beneficial effect in other respiratory disorders. The authors hypothesized that rhDNase would diminish atelectasis and mucus plugging in infants with severe RSV bronchiolitis. Two infants with RSV bronchiolitis with massive unilateral atelectasis in whom mechanical ventilation was imminent due to exhaustion, and three mechanically ventilated infants (two neonates, one with bronchopulmonary dysplasia) with RSV bronchiolitis with pneumonia received treatment with 2.5 mg nebulized rhDNase twice daily. Following administration of nebulized recombinant human deoxyribonuclease, clinical and radiological parameters improved quickly. Mechanical ventilation could be avoided in two infants while in three infants on artificial ventilation, clinical recovery started following the first dose of the drug. A therapeutic trial of recombinant human deoxyribonuclease may be an option in the treatment for atelectasis in severe or complicated respiratory syncytial virus bronchiolitis in infancy.

Administration, Inhalation↗
PubMed1976

The pathogenesis of respiratory syncytial virus infection in infant ferrets.

The infant ferret is susceptible to respiratory syncytial virus infection in both the upper and lower respiratory tracts. In the nose, viral replication is restricted to the surface respiratory epithelium in the nasal passages and turbinates. In the lungs, viral replication is of a lower order of magnitude and is localized in the alveolar cells. The pattern of viral replication in nasal tissues is independent of the age of the animal at infection, whereas the pattern in lung tissues shows a striking age dependence, with viral replication progressively decreasing as a function of age. Thes age dependence appears to be due to an intrinsic age-related mechanism yet to be defined. We feel that the infant ferret is an acceptable model for the study of respiratory syncytial virus disease and that the study of age dependence observed in ferrets may allow elucidation of the mechanisms involved in the age dependence seen in humans.

Aging↗
PubMed2003

Antiviral drugs in the immunocompetent host: part II. Treatment of influenza and respiratory syncytial virus infections.

Family physicians should be familiar with the various drugs available for treating and preventing viral infections. Part II of this two-part article focuses on agents used to manage influenza and respiratory syncytial virus. Rimantadine and amantadine traditionally have been used to prevent and treat influenza type A infections. The neuraminidase inhibitors zanamivir and oseltamivir have a broadened spectrum of activity in the treatment and prevention of influenza types A and B. Ribavirin has been used in some high-risk infants to treat respiratory syncytial virus infections, and palivizumab can be used for prophylaxis.

Antiviral Agents↗
PubMed1992

Effect of macrophages and in vitro infection with parainfluenza type 3 and respiratory syncytial viruses on the mitogenic response of bovine lymphocytes.

Bovine blood lymphocytes, depleted of macrophages by absorption on plasma-gelatin coated plastic flasks, followed by passage through Sephadex G-10 columns, failed to respond to pokeweed mitogen stimulation. Adherent monocytes or alveolar macrophages added to purified lymphocyte preparations at 10% or less were able to restore the transformation response. Exposure of alveolar macrophages or purified lymphocytes to 2 bovine respiratory syncytial virus strains for 24 hours substantially reduced the transformation response when mixed with uninfected lymphocytes or macrophages. Exposure of alveolar macrophages or purified lymphocytes to 2 bovine parainfluenza type 3 virus strains produced a similar reduction in activity after 48 hours. Heat inactivation of the viruses removed their inhibitory ability. Immunofluorescence studies revealed that both alveolar macrophages and lymphocytes were permissive for parainfluenza type 3 virus, whereas only a small number of alveolar macrophages and lymphocytes were infected with respiratory syncytial virus. The results suggest that both viruses are capable of adversely affecting the interaction between macrophages and lymphocytes, although the mechanisms by which this is achieved may be different.

Animals↗
PubMed2003

Recommendations for the use of palivizumab as prophylaxis against respiratory syncytial virus in infants with congenital cardiac disease.

New data are emerging on the use of palivizumab as prophylaxis against infection with the respiratory syncytial virus in infants with congenital cardiac disease. Following a 4-year multicentre randomised trial, it was shown that prophylactic injections with palivizumab were effective and safe for such children. Prophylaxis consists of 5, monthly, intramuscular injections of palivizumab, at a dose of 15 mg/kg, given during the season for infection with the respiratory syncytial virus. Timing is at the discretion of the physician, depending on the onset of the season locally. It is suggested that, in the United Kingdom, this should be commenced in mid-September. To help clinicians to identify appropriate candidates for palivizumab, a working group of the British Paediatric Cardiac Association has developed recommendations. Infants, namely those under 1 year old, with congenital cardiac disease likely to benefit from prophylaxis include those with haemodynamically significant lesions, particularly increased pulmonary blood flow with or without cyanosis; pulmonary venous congestion, pulmonary hypertension or long-term pulmonary complications, residual haemodynamic abnormalities following medical or surgical intervention (patients who have undergone cardiopulmonary bypass should receive an injection as soon as they are medically stable), cardiomyopathy requiring treatment, and congenital cardiac disease likely to need hospital admission for medical or surgical intervention during the season of infection with the virus. Prophylaxis with palivizumab may also be indicated, at the discretion of the physician, in some children with complex cardiac disease over the age of 1 year. Children less likely to benefit from prophylaxis are those with haemodynamically insignificant disease, or those with lesions adequately corrected by medical or surgical intervention.

Antibiotic Prophylaxis↗
PubMed1992

Comparison of three immunoassays for the rapid detection of bovine respiratory syncytial virus.

Three enzyme-linked immunosorbent assays (EIA) designed for the detection of human respiratory syncytial virus (RSV) were evaluated for the detection of bovine respiratory syncytial virus (BRSV) in bovine lungs and the results were compared with those obtained by a direct fluorescent antibody assay (DFA). The EIA tests used were Directigen EIA, Kallestad Pathfinder EIA, and Abbott RSV EIA. Homogenates of lung tissues obtained from 64 cattle that had died of respiratory disease were used; 32 were positive by DFA and 32 were negative. All EIA's varied in the amount of labor and time involved but their relative sensitivities were similar ranging between 59 and 66% when compared with DFA. The specificity of Pathfinder EIA was lower than those of the Directigen and Abbott tests. The overall agreement between the three EIA's and the DFA was 66-77% indicating that DFA is still the test of choice for detecting BRSV infection in lung tissues of cattle.

Animals↗
PubMed2004

[The anti-respiratory syncytial virus effect of an active compound (AP3) from a Chinese medicinal herb-Herba patriniae in vitro].

OBJECTIVE: To study the effect on anti-respiratory syncytial virus of an active compound (AP3) from a Chinese medicinal herb-Herba patriniae in vitro. METHODS: Active component of herba patriniae (AP3) was extracted and its anti-respiratory syncytial virus (RSV) effect was tested. A water soluble substance (AP3) was isolated from a Chinese herb Herba patriniae, by hot water extraction, ethol precipitation and gel permeation column chromatography. The cytotoxicity of AP3 was tested by adding it to HeLa cells directly. Its effect against RSV was estimated by CPEI assay while ribavirin was used as positive control. RESULTS: Chemical test showed that the nature of substance AP3 was polysaccharide. The median cytotoxic concentration (TC(50)) of AP3 was 11.45 mg/ml by morphological observation and the median effective concentration (50% effective concentration, EC(50)) of it against replication of the long strain of RSV in HeLa cells was 0.0986 mg/ml. The Therapeutic index (TI = TC(50)/EC(50)) of AP3 was 116.12, much higher than the TI of herba patriniae (AP1) (TI = 59.26) and ribavirin (TI = 53.45). Moreover, AP3 gave a dose-dependent response in inhibiting RSV. In the assay, the effect of AP3 against RSV growth was also tested. In addition, the effect of AP3 on virus growth, AP3 inhibited replication of RSV in HeLa cells, when added at 0 h, 2 h, 4 h after virus infection, were also tested. CONCLUSION: This study suggested that the AP3 exerted an obvious inhibitory effect to RSV in HeLa cell culture. This study furnished a reliable evidence for development of a new antiviral drug.

Antiviral Agents↗
PubMedDate not supplied

Respiratory syncytial virus pneumonia in a lung transplant recipient: case report.

A 29-year-old man underwent bilateral lung transplantation and received maintenance immunosuppressive therapy. He was readmitted 11 months later with symptoms of cough, sneezing, and rhinorrhea. The physical examination was normal. Laboratory results were significant for a reduction of FEV1 and an interstitial infiltrate on chest films. The patient had recently undergone bronchoscopy for rejection surveillance, and 2 days before admission the bronchoalveolar lavage cultures returned positive for respiratory syncytial virus. The patient was treated with aerosolized ribavirin with complete resolution of symptoms. Respiratory syncytial virus must now be included in the list of pathogens causing pneumonia in the lung transplant recipient.

Adult↗
PubMed2005

[Clinical study of feiyanqing rectum condensed liquid in treating 36 cases of children syncytial viral pneumonia].

OBJECTIVE: To evaluate the clinical efficacy and mechanism of Feiyangqin Rectum Condensed Liquid (FRCL) in treating children syncytial viral pneumonia. Methods Seventy-two patients were randomly divided into two groups, the 36 patients in the treated group were treated with FRCL, and the other 36 patients in the control group simply treated with Western medicine. Efficacy of treatment on clinical condition and some immune function (IgA, IgG, CD3, CD4) were observed. RESULTS: In the treated group, 28 patients were cured (77.8%), treatment was markedly effective in 4 patients (11.1%), effective in 2 (5.5%) and ineffective in 2 (5.6%), with the total effective rate of 94.4%. The corresponding number in the control group was 20 (55.6%), 7 (19.4%), 6 (16.7%), 3 (8.3%) and 91.7%, respectively. The cure rate in the treated group was obviously superior to that in the control group (P < 0.05). FRCL could improve serum IgA, IgG, CD3, CD4, and CD4/CD8, lower serum IgE, these indexes in the treated group were significantly different to those in the control group (P < 0.05). CONCLUSION: FRCL had the action in treating children syncytial viral pneumonia without any adverse reaction, one of its mechanisms might be related to its regulation on immune function.

Administration, Rectal↗
PubMed1991

Replication of parainfluenza type-3 virus and bovine respiratory syncytial virus in isolated bovine type-II alveolar epithelial cells.

The objectives of our research were to determine whether bovine pulmonary type-II alveolar epithelial cells could be isolated from bovine lung and maintained in tissue culture and to determine whether isolated bovine type-II alveolar epithelial cells would support productive viral replication of bovine parainfluenza type-3 virus and bovine respiratory syncytial virus. Type-II alveolar epithelial cells were isolated from lungs of 4- to 7-day-old male Holstein calves by enzymatic dissociation of pulmonary tissue with trypsin and by separation of cells with the use of filtration and centrifugation on continuous Percoll gradients. Cells were further separated by panning on IgG-coated plastic plates and by lectin binding. Isolated type-II alveolar cells were maintained on basement membrane-coated tissue cultured plates. In culture, type-II cells formed alveolar structures and maintained other cytologic features of type-II cells, including osmiophilic lamellar inclusions. Cell cultures were inoculated with and supported productive replication of bovine parainfluenza type-3 virus and bovine respiratory syncytial virus. This was determined by recovery of infectious viruses from inoculated cell cultures and by identification of viral structures in type-II alveolar epithelial cells by transmission electron microscopy.

Animals↗
PubMed1991

Effects of bovine respiratory syncytial virus on airway function in neonatal calves.

Respiratory syncytial virus (RSV) infection causes severe lower respiratory tract disease in infants and calves. Neonatal respiratory tract infection in children often produces persistent changes in lung function. The specific objective of this study was to determine whether neonatal calves have transient or persistent alterations in pulmonary function and airway reactivity following RSV infection. Six 2- to 3-day-old Holstein bull calves were inoculated with 10 ml of bovine respiratory syncytial virus (BRSV) inoculum (10(2.7) to 10(3.8) cell culture infective doses/ml) intranasally and 10 ml of BRSV inoculum (10(4.8) to 10(5.9) cell culture infective doses/ml) intratracheally for 4 consecutive days, and 5 other calves were sham-inoculated. Prior to inoculation (day 0) and on days 4, 14, and 30 after the last inoculation, body weight (kg), dynamic compliance (Cdyn), pulmonary resistance (RL), and 2 indices of airway reactivity (effective dose [ED] 65Cdyn and ED200RL) were measured. Control calves gained weight progressively throughout the study, whereas RSV-inoculated calves failed to gain weight for 14 days, but equaled control calf weight by 30 days after inoculation. The Cdyn of control calves increased significantly by 30 days, but did not in the RSV-infected calves. Pulmonary resistance was increased significantly at 4, 14, and 30 days, but was unaffected by sham inoculation. The ED65Cdyn and ED200RL indicated an age-dependent increase in reactivity to histamine and an increase in responsiveness in the infected group beginning at 14 days and persisting until the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1991

Culture vs direct antigen assays for detection of microbial pathogens from lower respiratory tract specimens suspected of containing the respiratory syncytial virus.

Following the introduction of effective antiviral chemotherapy, rapid antigen assays have been utilized increasingly, instead of cell cultures, for detection of the respiratory syncytial virus from lower respiratory tract specimens. Because antigen assays, unlike cell culture, cannot amplify low levels of the virus to a detectable level, assay sensitivity is especially dependent on high-quality specimens. In addition, the assays are unable to detect other viruses or bacteria with which the patient may be infected. This review summarizes results from clinical studies of the performance of cell cultures and the more commonly used antigen assays, describes factors that may lead to false-positive or false-negative test results, and makes recommendations for the selection of procedures for the reliable detection of microbial pathogens from patients suspected of being infected with respiratory syncytial virus.

Antigens, Viral↗
PubMed1990

[A bronchiolitis epidemic caused by respiratory syncytial viruses].

In the typical period of the year (autumn-winter 1986-1987) an outbreak of bronchiolitis in infants caused by respiratory syncytial virus (RSV) occurred. The acute course of the illness, a severe clinical picture, and a very fast spread of infection called for the very rapid techniques for detecting the etiological agent. Applying the direct immunofluorescent antibody test (DFTA) in samples of nasopharyngeal secretions, RSV was found to be responsible for the epidemic. Later the same samples of the material were inoculated into tissue cultures and RSV was isolated. Fourfold or higher titres of complement fixing antibodies in paired serum samples confirmed the infection with RSV. During the outbreak of bronchiolitis 72 children aged under 15 months (only one child was older than one year) were hospitalized. The majority of cases of RSV bronchiolitis was noticed in infants in the first six months of life (81.9%, chi 2 = 31.1, p less than 0.01). Boys against girls were in relation as 1.25:1. Because of the broncho-obstructive component of the illness, respiratory failure was the dominant sign in the clinical picture of bronchiolitis; 34.7% of the patients were afebrile, 16.7% were in the state of hyperpyrexy and 48.6% with temperature up to 38 degrees C. Oxygen and symptomatic therapy were the basic treatment. In severe cases corticosteroids and antibiotic were administered for a short time. The classical type of bronchiolitis in infancy as the most severe among acute infections of respiratory organs because of its poor prognosis at the very beginning and the long-term sequels is a serious medical problem. Emphasis is laid on the importance and usefulness of the virologic diagnosis, especially the application of rapid DFTA techniques in the acute stages of bronchiolitis caused by infections with respiratory syncytial virus during the epidemic occurrence of this agent.

Bronchiolitis, Viral↗
PubMed1989

Pathogenesis of naturally acquired bovine respiratory syncytial virus infection in calves: morphologic and serologic findings.

Lesions in 32 calves that died or were euthanatized during the course of severe natural infection with bovine respiratory syncytial virus (BRSV) are described. All calves had been dyspneic for 1 to 2 days. At necropsy, lesions that could be related to dyspnea included congested and cyanotic mucosae and widespread petechiae. The lungs had various lesions in the cranioventral (CV) and caudodorsal (CD) portions. The CV portion of the lungs was consolidated, firm, and edematous. Histologically, the main characteristic was degenerative, necrotic bronchiolitis, with few syncytial cells. Signs of repair, such as epithelial hyperplasia, fibrosis, and bronchiolitis obliterans, often were observed. The CD portion of the lungs was markedly distended, owing to severe edema and emphysema. Bronchiolar lesions were lacking in the CD portion. In 14 calves, hyaline membranes were seen in the CV and CD portions. Results of immunofluorescence for BRSV were positive in 24 calves, but only in the CV portion of the lungs. The calves had variable concentrations of BRSV-specific IgG1 and IgM in serum, lung lavage fluid, or both. The BRSV-specific IgA, on the contrary, was seldom detected. Thus, 2 discrepancies existed. Although the clinical picture appeared to be acute, bronchiolar lesions and serotest results suggested infection of longer duration. Also, although virus and viral cytopathologic features were detected only in the CV portion of the lungs, the CD portion had extensive lesions that consisted of emphysema and edema.

Animals↗
PubMed1989

Fatty acid acylation of the fusion glycoprotein of human respiratory syncytial virus.

We describe the covalent attachment of palmitate to the fusion glycoprotein of respiratory syncytial virus and the identification of the attachment site. Labeling of respiratory syncytial virus-infected Vero cells with [3H]palmitate, followed by the purification and subsequent analysis of the fusion glycoprotein in conjunction with polyacrylamide gel electrophoresis, demonstrated that the fatty acid is covalently attached to the F1 subunit of the fusion glycoprotein. The bound palmitate was sensitive to 1 M hydroxylamine at neutral pH. In addition, the release of palmitate label by reduction with sodium borohydride showed that the palmitate is linked to the protein through a thioester bond. Isolation of a radiolabeled peptide from a tryptic digest of the protein and subsequent amino-terminal sequence analysis revealed that the cysteine residue (amino acid residue 550) within the anchor sequence, located at the carboxyl terminus of the F1 subunit, is the covalent attachment site for palmitate.

Acylation↗