Review of epidemiology and clinical risk factors for severe respiratory syncytial virus (RSV) infection.
ABSTRACT Respiratory syncytial virus (RSV) infection is the most frequent reason for hospitalization of infants in developed countries. Premature birth without or, especially, with chronic lung disease of prematurity, congenital heart disease, and T-cell immunodeficiency are conditions that predispose to more severe forms of RSV infection. Incomplete development of the airway, damage to the airway, and airway hyperreactivity underlie the increased morbidity of RSV infection in prematurely born infants. Pulmonary hypertension and cyanosis are associated with worse outcomes in infants with congenital heart disease, and prolonged viral replication accounts for more severe illness in immunocompromised individuals.
SourceAvailable from: Suresh K Bhavnani[Show abstract] [Hide abstract]
ABSTRACT: Although influenza (flu) and respiratory syncytial virus (RSV) infections are extremely common in children under two years and resolve naturally, a subset develop severe disease resulting in hospitalization despite having no identifiable clinical risk factors. However, little is known about inherent host-specific genetic and immune mechanisms in this at-risk subpopulation. We therefore conducted a secondary analysis of statistically significant, differentially-expressed genes from a whole genome-wide case-control study of children less than two years of age hospitalized with flu or RSV, through the use of bipartite networks. The analysis revealed three clusters of cases common to both types of infection: core cases with high expression of genes in the network core implicated in hyperimmune responsiveness; periphery cases with lower expression of the same set of genes indicating medium-responsiveness; and control-like cases with a gene signature resembling that of the controls, indicating normal-responsiveness. These results provide testable hypotheses for at-risk subphenotypes and their respective pathophysiologies in both types of infections. We conclude by discussing alternate hypotheses for the results, and insights about how bipartite networks of gene expression across multiple phenotypes can help to identify complex patterns related to subphenotypes, with the translational goal of identifying targeted therapeutics.04/2014; 2014:29-34.
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ABSTRACT: Acute viral bronchiolitis by Respiratory Syncytial Virus (RSV) is the most common respiratory illness in children in the first year of life. RSV bronchiolitis generates large numbers of hospitalizations and an important burden to health systems. Neutrophils and their products are present in the airways of RSV-infected patients who developed increased lung disease. Neutrophil Extracellular Traps (NETs) are formed by the release of granular and nuclear contents of neutrophils in the extracellular space in response to different stimuli and recent studies have proposed a role for NETs in viral infections. In this study, we show that RSV particles and RSV Fusion protein were both capable of inducing NET formation by human neutrophils. Moreover, we analyzed the mechanisms involved in RSV Fusion protein-induced NET formation. RSV F protein was able to induce NET release in a concentration-dependent fashion with both neutrophil elastase and myeloperoxidase expressed on DNA fibers and F protein-induced NETs was dismantled by DNase treatment, confirming that their backbone is chromatin. This viral protein caused the release of extracellular DNA dependent on TLR-4 activation, NADPH Oxidase-derived ROS production and ERK and p38 MAPK phosphorylation. Together, these results demonstrate a coordinated signaling pathway activated by F protein that led to NET production. The massive production of NETs in RSV infection could aggravate the inflammatory symptoms of the infection in young children and babies. We propose that targeting the binding of TLR-4 by F protein could potentially lead to novel therapeutic approaches to help control RSV-induced inflammatory consequences and pathology of viral bronchiolitis.PLoS ONE 04/2015; 10(4):e0124082. DOI:10.1371/journal.pone.0124082 · 3.53 Impact Factor
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ABSTRACT: Background: Bronchiolitis is most commonly presents in infants aged three to six months. The objectives of this study were to determine the risk factors and clinical presentation of bronchiolitis in Sudanese children attending GaafarIbn A of Hospital for children in Khartoum. Methods: The study design was descriptive. All children less than two years of age admitted to the hospital during the study period with the criteria fulfilling the diagnosis of acute bronchiolitis were enrolled in the study. The sample size was taken as 100. Data were collected by a questionnaire and medical examination. Informants for the questionnaire were the children mothers. Data was analyzed by SPSS software. Results: Children aged 0-6, 7-12 and more than 12 months constituted 68%, 19% and 13% respectively. Most children (92%) had siblings and 78%lived in un crowded environment at home. As regards parental smoking, 36% of the parents were cigarette smokers. Results showed that 34% of children had a past history of hospitalization. Seven percent of the children were delivered as pre term. The most common clinical presentation of bronchiolitis were cough, wheeze and shortness of breath constituted 87%, 82% and 64% respectively. Conclusion: The risk factors for Bronchiolitis were young age (0-6 months), presence of a sibling, a history of hospital admission and paternal history of tobacco smoking. The most common clinical presentations were cough, wheeze and crepitation.