Comparison of Nasal Wash and Nasopharyngeal Swab for Multiplex-PCR Respiratory Virus Detection

BACKGROUND: High-throughput, multiplex-PCR virus detection methods have made it easier to identify multiple respiratory viruses, but associated processes commonly require both a clinic visit and a clinician to collect a nasal sample. While several collection methods exist, nasal washes (NW) are considered the gold standard, and therefore more regularly used. However, self-collected nasopharyngeal swabs (NPS) may be a better alternative for some purposes.

METHODS: Research participants with acute respiratory infections using Jackson scale criteria obtained a self-collected nasopharyngeal swab at home, and then a nasal wash from a research nurse in a hospital setting within 72 hours of illness onset. Viral identification was performed on both samples using a high-throughput PCR-based multiplex method.

RESULTS: Across 205 ARI episodes in 200 participants, the estimated accuracy of nasopharyngeal swabs was .902 (95% CI .943, .862) as compared to nasal washes. The true positive rate and false positive rate were .858 and .043 respectively.

CONCLUSIONS: Self-collected nasopharyngeal swabs may be as effective as nasal washes for identification of common respiratory viruses using multiplex-PCR detection methods. Furthermore, avoiding the need of a clinic visit to obtain a sample could reduce the spread of illness, reduce the time and inconvenience burden of sampling, and could potentially yield more accurate data with earlier sample collection.