Multiple-Specimen Testing More Than Doubles RSV Detection in Hospitalized Adults
A new multicenter study reveals that testing multiple specimen types, including saliva and sputum, more than doubles the detection rate of respiratory syncytial virus (RSV) compared to the standard single nasopharyngeal swab (NPS) method. The findings offer a major advance in the accurate diagnosis and surveillance of RSV among adults hospitalized with acute respiratory illness (ARI).
Conducted across seven hospitals in the US and Canada, the study enrolled 3669 adults aged 40 years and older. All participants met criteria for ARI and underwent comprehensive specimen collection, including NPS, saliva, sputum, and paired serum samples. When all specimen types were used, RSV detection increased by 112% compared to NPS alone. Notably, serology had the highest sensitivity (73.0%), followed by sputum (70.1%), saliva (61.4%), and NPS (47.2%).
Among patients hospitalized for congestive heart failure exacerbations, detection increased by a striking 267% with additional specimens, highlighting the particular utility of saliva testing in cardiac patients. Furthermore, timing of specimen collection proved critical as NPS obtained one day later detected 30% fewer RSV infections.
The results underscore the limitations of relying solely on NPS for RSV surveillance and support incorporating multiple specimen types into clinical practice and research. Saliva, in particular, demonstrated greater sensitivity than NPS and was nearly universally collected, reinforcing its potential role as a practical and scalable diagnostic tool—especially in older adults and those with comorbidities.
The authors recommend applying a two-fold correction factor to RSV burden estimates based on NPS alone, a move that could significantly improve the accuracy of incidence and prevalence data used by public health officials.
Reference
Begier E, Aliabadi N, Ramirez JA. Detection by nasopharyngeal swabs alone underestimates respiratory syncytial virus–related hospitalization incidence in adults: the multispecimen study's final analysis. J Infect Dis. 2025:jiaf204. doi:10.1093/infdis/jiaf204
