Background: Early and accurate detection of respiratory viruses (RV) is important for patient management. We have previously shown that self-collected nasal swabs (NS) are feasible and as sensitive as clinician-collected nasal washes for detection of RV, but the additive benefit of self-collected throat swabs is unknown.
Objectives: To test the rise in auto sufficient nasal yields to the throat swabs in patients with upper respiratory (URTI) symptoms for PCR identification of RV.
Study Design: Patients with URTI symptoms self-collected paired polyurethane foam NS and nylon flocked throat swabs and completed a symptom survey. Swabs were tested for 12 RV by real-time reverse transcription (RT)-PCR. Descriptive, McNemar's, and Wilcoxon signed rank statistical tests were used.
Results: The sample was made up of 115 paired swab nasals and throat, with at least 1 specimen being positive for RV (71/115 (62 percent), including 51 positive for both specimens, 17 positive for NS only and 3 favorable for RV only with throat swab. NS was 96 percent sensitive (95 percent CI: 88-99) compared with 76 per cent in throat swabs, p < 0.001 (95 percent CI: 65-85). The median PCR period threshold (Ct) of 51 concordant samples was lower in NS (25.1) than in swabs of the throat (32.0).
Conclusion: Self-collection of NS was significantly more sensitive than self-collection of throat swabs for detection of RV by RT-PCR. The addition of throat sampling does not appear to increase the diagnostic load in the self-testing setting.