Viral Shedding and Immune Responses to Respiratory Syncytial Virus Infection in Older Adults.

Department of Medicine.
The Journal of Infectious Diseases (Impact Factor: 5.78). 02/2013; DOI: 10.1093/infdis/jit038
Source: PubMed

ABSTRACT Background. Comprehensive analyses of host, viral and immune factors associated with severe Respiratory Syncytial Virus (RSV) infection in adults have not been performed.Methods. Adults with RSV infection identified in both outpatient and inpatient settings were evaluated. Upper and lower respiratory viral load and duration of shedding, selected mucosal chemokine and cytokine levels, humoral and mucosal immunoglobulin responses, and systemic T cell responses were measured.Results. 111 RSV infected adults (61 outpatients, 50 hospitalized) were evaluated. Hospitalized subjects shed virus in nasal secretions at higher titers and longer than less ill outpatients, had greater mucosal interleukin (IL)-6 levels throughout infection, and higher MIP-1α levels early in infection. Persons >64 years old and those with more severe disease had a higher frequency of activated T cells in the blood than younger less ill subjects at infection. Multivariate analysis found that the presence of underlying medical conditions, female sex, increased mucosal IL-6, and longer duration of virus shedding were associated with severe disease. Older age and increased nasal MIP-1α levels were of borderline significance.Conclusion. Multiple factors, but not older age, are independently associated with severe RSV in adults. The presence of underlying medical conditions had the greatest influence on disease severity.

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