Factors associated with severe respiratory syncytial virus disease in hospitalised children: a retrospective analysis

BackgroundEarly recognition of children at risk of severe respiratory syncytial virus (RSV) lower respiratory tract infection is important as it informs management decisions. We aimed to evaluate factors associated with severe disease among young children hospitalised with RSV infection.MethodsWe conducted a retrospective cohort study of all children <2 years of age hospitalised for RSV lower respiratory tract infection at a single tertiary paediatric hospital over three RSV seasons (January 2017–December 2019). We classified children as having ‘moderate’ or ‘severe’ disease based on the level of respiratory intervention and used univariable and multivariable regression models to determine factors associated with severe disease.ResultsOf 970 hospitalised children, 386 (40%) were classified as having ‘severe’ and 584 (60%) as having ‘moderate’ RSV disease. On multivariable analyses, age <2 months (OR: 2.3, 95% CI 1.6 to 3.3, p<0.0001), prematurity (OR: 1.6, 95% CI 1.1 to 2.4, p=0.02) and RSV–parainfluenza virus type 3 (PIV3) codetection (OR: 2.6, 95% CI 1.05 to 6.5, p=0.04) were independently associated with severe disease.ConclusionYounger age, prematurity and PIV3 codetection were associated with severe RSV disease in children <2 years of age hospitalised with RSV infection. The association between PIV3 and severe RSV disease is a novel finding and warrants further investigation.

Gene signature of children with severe respiratory syncytial virus infection

Background The limited treatment options for children with severe respiratory syncytial virus (RSV) infection highlights the need for a comprehensive understanding of the host cellular response during infection. We aimed to identify host genes that are associated with severe RSV disease and to identify drugs that can be repurposed for the treatment of severe RSV infection. Methods We examined clinical data and blood samples from 37 hospitalized children (29 mild and 8 severe) with RSV infection. We tested RNA from blood samples using next-generation sequencing to profile global mRNA expression and identify cellular processes. Results Retractions, decreased breath sounds, and tachypnea were associated with disease severity. We observed upregulation of genes related to neutrophil, inflammatory response, blood coagulation, and downregulation of genes related to T cell response in children with severe RSV. Using network-based approach, 43 drugs were identified that are predicted to interact with the gene products of these differentially expressed genes. Conclusions These results suggest that the changes in the expression pattern in the innate and adaptive immune responses may be associated with RSV clinical severity. Compounds that target these cellular processes can be repositioned as candidate drugs in the treatment of severe RSV. Impact Neutrophil, inflammation, and blood coagulation genes are upregulated in children with severe RSV infection. Expression of T cell response genes are suppressed in cases of severe RSV. Genes identified in this study can contribute in understanding the pathogenesis of RSV disease severity. Drugs that target cellular processes associated with severe RSV can be repositioned as potential therapeutic options.