Relative Contribution of Diagnostic Testing to the Diagnosis of Respiratory Syncytial Virus in Hospitalized Adults in the United States

Background Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illness (ARI) in older adults. Optimizing diagnosis could improve understanding of RSV burden.Methods We enrolled adults >= 50 years of age hospitalized with ARI and adults of any age hospitalized with congestive heart failure or chronic obstructive pulmonary disease exacerbations at 2 hospitals during 2 respiratory seasons (2018-2020). We collected nasopharyngeal (NP) and oropharyngeal (OP) swabs (n = 1558), acute and convalescent sera (n = 568), and expectorated sputum (n = 153) from participants, and recorded standard-of-care (SOC) NP results (n = 805). We measured RSV antibodies by 2 immunoassays and performed BioFire testing on respiratory specimens.Results Of 1558 eligible participants, 92 (5.9%) tested positive for RSV by any diagnostic method. Combined NP/OP polymerase chain reaction (PCR) testing yielded 58 positives, while separate NP and OP testing identified 11 additional positives (18.9% increase). Compared to study NP/OP PCR alone, the addition of paired serology increased RSV detection by 42.9% (28 vs 40) among those with both specimen types, while the addition of SOC swab PCR increased RSV detection by 25.9% (47 vs 59).Conclusions The addition of paired serology testing, SOC swab results, and separate testing of NP and OP swabs improved RSV diagnostic yield in hospitalized adults. In this prospective surveillance study spanning 2 respiratory seasons from 2018 to 2020, the addition of paired serology testing, standard-of-care PCR results, and separate testing of nasopharyngeal and oropharyngeal swabs improved RSV diagnostic yield among hospitalized adults.