Self-Collected Oral-Nasal Swabs Fall Short for Detecting Influenza and RSV

A study conducted at Michael Garron Hospital, Toronto, Ontario, Canada, suggests that self-collected oral-nasal swabs may not be reliable substitutes for traditional nasopharyngeal swabs when testing adults for respiratory viruses such as influenza and respiratory syncytial virus (RSV).

The research, carried out in the hospital’s emergency department, evaluated the diagnostic performance of a self-collected oral-nasal swab against the gold standard provider-collected nasopharyngeal swab. Adult patients presenting with respiratory symptoms from January 18, 2023 to March 31, 2023, and October 28, 2023 until March 6, 2024, participated in the study. Participants self-collected oral and nasal samples after routine clinical nasopharyngeal swabs were performed.

Among the 128 participants, 48 individuals tested positive for either Influenza, RSV, or SARS-CoV-2, while 80 tested negative. The majority (110 individuals) were symptomatic, with a median time of 1 day between symptom onset and testing.

The findings revealed that while self-collected swabs demonstrated high specificity—99% for RSV and 96% for influenza—the sensitivity was notably lower. Sensitivity for detecting RSV stood at 75%, while for influenza it was just 67%, suggesting a considerable risk of false-negative results when relying on self-collection.

According to the authors, this study is the first to report on the performance of oral-nasal swabs for multiplex viral testing, a method that could play a critical role in pandemic preparedness if proven effective. However, given the current data, the researchers recommend that nasopharyngeal swabs remain the standard of care for detecting influenza and RSV infections in emergency settings.

Further research into alternative specimen collection methods remains necessary, particularly in anticipation of future respiratory virus outbreaks that could strain health care systems and demand scalable, patient-friendly testing solutions.

Reference

Young M, Suico Y, Vojdani OK. Validation of oral-nasal specimen collection for influenza and respiratory syncytial virus detection. Antimicrob Steward Healthc Epidemiol. 2025;5(1):e99. doi: 10.1017/ash.2025.66