In older hospitalized adults, infection with respiratory syncytial virus (RSV) may be associated with greater morbidity and mortality compared with influenza, according to the results of an observational, retrospective study conducted at Kaiser Permanente Southern California (KPSC). Findings from the analysis were published in Clinical Infectious Diseases.
The study population comprised hospitalized KPSC members ≥60 years of age at the time of admission who had a positive RSV or influenza A/B laboratory test (multiplex real-time polymerase chain reaction or viral culture) between January 1, 2011, and June 30, 2015, at 1 of 15 KPSC hospitals. Investigators compared baseline characteristics, comorbidities, outcomes, and utilization between individuals with RSV and individuals with influenza infection.
A total of 645 adults with RSV and 1878 adults with influenza participated in the study. Most infections were detected with multiplex polymerase chain reaction (RSV=91.8%; influenza=82.6%). Patients who had RSV were slightly older than those with influenza (mean age, 78.5 years vs 77.4 years, respectively; P =.035). In addition, patients with RSV vs influenza were significantly more likely to have congestive heart failure (35.3% vs 24.5%, respectively; P <.001), as well as chronic obstructive pulmonary disease, chronic bronchitis, or emphysema (29.8% vs 24.3%, respectively; P =.006) at baseline.
According to adjusted analyses, RSV infection was associated with a significantly greater likelihood for hospital stay of ≥7 days (odds ratio [OR], 1.5; 95% CI, 1.2-1.8; P <.001); pneumonia diagnosis during hospitalization (OR, 2.7; 95% CI, 2.2-3.2; P <.001); admission to the intensive care unit (OR, 1.3; 95% CI, 1.0-1.7; P =.023); exacerbation of chronic bronchitis, chronic obstructive pulmonary disease, or emphysema (OR, 1.7; 95% CI, 1.3-2.4; P =.001); and greater long-term mortality within 1 year of hospital admission (OR, 1.3; 95% CI, 1.0-1.6; P =.019).
The investigators concluded that the increased recognition of RSV disease burden in older adults will be key to the evaluation and use of RSV vaccines and antiviral agents following their introduction.
Disclosures: Dr Shinde is an employee of Novavax and is also a Novavax shareholder. Drs Shinde, Tseng, Sy, Ackerson, Fischetti, Slezak, Luo, and Solano received research funding from Novavax. For a full list of disclosures, please visit the reference online.
Ackerson B, Tseng HF, Sy LS, et al. Severe morbidity and mortality associated with respiratory syncytial virus versus influenza infection in hospitalized older adults [published online November 19, 2018]. Clin Infect Dis. doi:10.1093/cid/ciy991