Host inflammatory response is the major marker of severe respiratory syncytial virus infection in older adults

Objectives: We aim to study the viral kinetics and host inflammatory response of RSV infection in older adults, and their correlation with disease severity. Methods: We performed a prospective observational study in adults with RSV infection. We serially collected nasal-throat swabs for quantification of RSV-A and RSV-B viral load, and peripheral blood samples for measurement of cytokine/chemokine concentrations. The study endpoints were (i) requiring supplemental oxygen therapy, and (ii) non-invasive ventilation, intensive care, or died within 30 days of admission. We performed multivariable logistic regression models to identify independent variables for severe disease. Results: We enrolled 71 hospitalized patients and 10 outpatients treated for RSV infection (median age 75 years, 51% male, and 74% with comorbidities). Among hospitalized patients, 61% required supplemental oxygen therapy, and 18% had severe disease requiring non-invasive ventilation or intensive care, or died within 30 days. Inflammatory cytokine/chemokines IL-6, CXCL8/IL-8, CXCL9/MIG and CXCL10/IP-10 increased significantly during the acute phase of illness. IL-6 concentration was independently associated with severe disease after adjusting for confounding factors. RSV viral load was not associated with disease severity throughout the course of illness. Conclusion: Host inflammatory response is a major marker of severe disease in older adults with RSV infection. (c) 2021 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study aimed to investigate the viral kinetics, host inflammatory response, and their correlation with disease severity in older adults with RSV infection. The results showed that inflammatory cytokine IL-6 was independently associated with severe disease, while RSV viral load was not associated with disease severity.