The optimal method for identifying respiratory viruses in adults has not been established. The objective of the study was to compare the sensitivity of three sampling methods for this purpose.
One thousand participants were included (mean age 63.1 ± 17.8 years). Of these 550 were patients hospitalized for acute febrile lower respiratory tract infections and 450 were controls. Oropharyngeal swabs (OPS), nasopharyngeal swabs (NPS) and nasopharyngeal washings (NPW) were obtained from each participant and were tested for 12 respiratory viruses by multiplex based real time PCR (mqRT-PCR). Patients were defined as positive (gold standard) for a specific virus if the virus was identified by at least one sampling method.
In all, 251 viruses were identified in 244 participants. For the detection of any virus sensitivity rates for OPS, NPS and NPW were 54.2%, 73.3%, and 84.9%, respectively (OPS vs. NPS and NPW P < 0.00001; NPS vs. NPW P < 0.003). A sensitivity of 100% was obtained only with sampling by all three methods. The same gradation of sensitivity for the three sampling methods was found when influenza viruses, coronaviruses and rhinoviruses were analyzed separately. The three sampling methods yielded equal sensitivity rates for RSV.
Nasopharyngeal sampling has a higher sensitivity rate than oropharyngeal sampling and NPW has a higher sensitivity than NPS for the identification of respiratory viruses in adults.
Sampling by all three methods is required for maximal detection of respiratory viruses.
David Lieberman, No Financial Disclosure Information; No Product/Research Disclosure Information