Abstract
BACKGROUND: In adults, the infectious etiologies of acute respiratory illnesses (ARIs) and of exacerbations of cardiopulmonary diseases requiring hospitalization are incompletely understood. METHODS: We conducted a prospective surveillance study of older adults hospitalized with acute respiratory illness (ARI) and adults of any age hospitalized with exacerbations of congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD) at 2 urban hospitals in Atlanta, Georgia, during the 2018-2019 and 2019-2020 respiratory seasons along with contemporaneous healthy controls. All participants had nasopharyngeal and oropharyngeal swabs collected and tested for common viral and bacterial etiologies using a BioFire multiplexed respiratory panel. A subset of patients had paired serological testing for respiratory syncytial virus (RSV), and standard-of-care microbiologic testing results were included when available. Demographics, clinical characteristics, and outcomes were determined through a combination of participant interview and medical record abstraction for hospitalized participants. RESULTS: A total of 1558 participants were enrolled and included in the analysis. Overall, 757 participants (48.6%) were hospitalized for ARI, 490 (31.5%) for CHF exacerbation, and 311 (20.0%) for COPD exacerbation. At least 1 pathogen was detected in 476 (30.6%) participants, most commonly rhinovirus/enterovirus (127/1558 [8.2%]), influenza (119/1558 [7.6%]), and RSV (92/1558 [5.9%]). Although bacterial and fungal infections were uncommon, these were associated with severe clinical outcomes, including duration of hospitalization and mechanical ventilation. CONCLUSIONS: Respiratory viruses contributed substantially to hospitalization for ARI and cardiopulmonary exacerbations among our cohort of high-risk adults, underscoring the need for effective therapeutic and preventive interventions in this vulnerable population.