Why carry out this study?

Adding the collection and testing of additional specimen types to NP swab RT–PCR increases RSV detection, but prior studies only made pairwise comparisons and the synergistic effect of adding multiple specimen types has not yet been quantified.

We sought to compare RSV diagnosis by PCR testing of NP swab alone versus NP swab plus saliva, sputum, and serology.

What was learned from the study?

RSV was diagnosed in 56 (3.2%) patients by NP swab alone, and in 109 (6.2%) patients by NP swab plus additional specimens, corresponding to a 1.95 times higher diagnosis rate (95% CI 1.62, 2.34).

Approximately half of identified positives were missed by NP swab testing, even with a relatively low percentage of subjects with sputum and serology results available.

Hospitalized RSV ARI burden estimates in adults based solely on NP swab RT–PCR should be adjusted for underestimation.