Methods: Surveillance occurred October 1–April 30 (2014–2017) at sites located in 7 states (California, Georgia, Michigan, Minnesota, New York, Oregon, and Tennessee) covering an annual catchment population of up to 13 million adults ≥18 years. Laboratory-confirmed RSV cases were identified using hospital and state public health laboratories, hospital infection preventionists, and/or reportable condition databases. Medical charts were reviewed for demographic and clinical data. International Classification of Diseases (ICD) discharge codes were abstracted. Odds ratios (OR) and 95% confidence intervals (CI) were determined to assess risk factors for ICU hospitalization and deaths.
Results: 2,326 hospitalized RSV cases were identified. Over half were ≥65 years (62%, n=1438/2326), female (59%, n=1362/2326), white (70%, n=1301/1855), and had ≥3 underlying medical conditions (52%, n=1204/2326). 20% (n=398/2000) were hospitalized in the ICU (median length of stay, 3 days; interquartile range, 1–6 days), and 5% (n=96/2001) died in the hospital. Congestive heart failure (CHF; OR: 1.4, 95% CI: 1.1–1.8) and chronic obstructive pulmonary disease (COPD; OR: 1.3, 95% CI: 1.1–1.7) were associated with ICU admission, while age ≥80 years (OR: 4.1, 95% CI: 1.8–12.1) and CHF (OR: 2.4, 95% CI: 1.6–3.6) were associated with in-hospital deaths. RSV-specific ICD codes were listed in the first 9 positions in only 44% (879/1987) of cases.
Conclusion: To our knowledge, this is the largest U.S. case series of RSV-infected hospitalized adults. Most cases were ≥65 years and had multiple underlying medical conditions. Older age, CHF, and COPD were associated with the most severe outcomes. Few cases had RSV-specific ICD codes, suggesting that administrative data underestimate adult RSV-related hospitalizations. Continued surveillance is needed to understand the epidemiology of RSV among adults as vaccine products move toward licensure.
P. D. Kirley, None
E. J. Anderson, NovaVax: Grant Investigator , Research grant . Pfizer: Grant Investigator , Research grant . AbbVie: Consultant , Consulting fee . MedImmune: Investigator , Research support . PaxVax: Investigator , Research support . Micron: Investigator , Research support .
S. Eckel, None
K. Como-Sabetti, None
E. M. Dufort, None
C. B. Felsen, None
C. Crawford, None
H. K. Talbot, Sanofi Pasteur: Investigator , Research grant . Gilead: Investigator , Research grant . MedImmune: Investigator , Research grant . Vaxinnate: Safety Board , none . Seqirus: Safety Board , none .
G. E. Langley, None
S. I. Gerber, None