Hospitalisation, morbidity and outcomes associated with respiratory
syncytial virus compared to influenza in adults of all ages
Abstract
Background: Respiratory syncytial virus (RSV) is understood to be a
cause of significant disease in older adults and children. Further
analysis of RSV in younger adults may reveal further insight into its
role as an important pathogen in all age groups. Methods: We identified,
through laboratory data, adults who tested positive for either influenza
or RSV between January 2017 and June 2019 at a single Australian
hospital. We compared baseline demographics, testing patterns,
hospitalisations and outcomes between these groups. Results: Of 1128
influenza and 193 RSV patients, the RSV cohort was older (mean age 54.7
vs. 64.9, p<0.001) and were more comorbid as determined by the
Charlson Comorbidity Index (2.4 vs. 3.2, p<0.001). Despite
this, adults under 65 with RSV were equally likely to be admitted
compared with their influenza counterparts (70.3% vs. 77.3%, p=0.174).
Testing occurred later in RSV hospitalisations as measured by the
proportion tested in the emergency department (80.3% vs. 69.2%,
p<0.001) and this was strongly associated with differences in
presenting phenotype (the presence of fever). RSV was the biggest
predictor of 6 month representation, with age and comorbidities
predicting this less strongly. Conclusion: RSV is a significant
contributor to morbidity and hospitalisation, sometimes outweighing that
of influenza, and is not limited to elderly cohorts. Understanding key
differences in the clinical syndrome and consequent testing paradigms
may allow better detection and potentially treatment of RSV to reduce
individual morbidity and health system burden. This growing area of
research helps quantify the need for directed therapies for RSV.