Respiratory syncytial virus infection in older adults: an under-recognized problem.

Human respiratory syncytial virus (RSV) is an enveloped, single-stranded, negative-sense RNA virus and member of the Paramyxoviridae family of the genus Pneumovirus that was first reported as a major pathogen in pediatric populations. However, since its discovery, RSV has not infrequently been detected in adults. Reinfection occurs throughout life, with more severe disease occurring in older adults, immunocompromised patients, and those with underlying cardiopulmonary disease. Initially described as the cause of nursing home outbreaks of respiratory disease, there is a now significant body of literature describing the clinical importance of RSV in older adults in a multitude of settings including long-term care, adult daycares, and in community-dwelling adults. Moreover, recent reports from China and other countries emphasize that RSV is a global pathogen that will become increasingly important in developed nations with aging populations. Annual attack rates in the USA range from 2 to 10% in community-dwelling older adults and 5-10% in older adults living in congregate settings. Population-based calculations of the proportion of acute respiratory illnesses attributable to RSV estimate that 11,000 elderly persons die annually in the USA of illnesses related to RSV infection. Clinical manifestations of RSV infections are similar to that of other viral respiratory pathogens and include cough, nasal congestion, rhinorrhea, sore throat, and dyspnea. Lower respiratory tract disease is common and may result in respiratory failure (8-13%) or death (2-5%). Recent advances in molecular diagnostics have made it possible to rapidly identify RSV infection using nucleic acid amplification tests, although clinicians will need to suspect the diagnosis when viral activity is high. At the present time, treatment is supportive. Effective antiviral agents for the treatment and vaccines for prevention of RSV remain a significant unmet medical need in the older adult population.