Comparison among nasopharyngeal swab, nasal wash, and oropharyngeal swab for respiratory virus detection in adults with acute pharyngitis

Abstract

BackgroundAcute pharyngitis is frequently seen in primary care. Acute viral pharyngitis may be easily misdiagnosed as acute bacterial pharyngitis. Laboratory-confirmed diagnosis of respiratory viruses is recommended. The purpose of this study was to compare the sensitivities among oropharyngeal swab (OPS), nasopharyngeal swab (NPS), and nasal wash (NW) in adults with acute pharyngitis.MethodsOPS, NPS, and NW were obtained from each participant with acute pharyngitis. The specimens were tested for 15 respiratory viruses by TaqMan real-time polymerase chain reaction. A sample was considered to be a true positive if any of the specimens was positive. The sensitivities among samples were compared by chi-square test or Fisher’s exact test, as appropriate.ResultsOne hundred three triple samples collected consecutively by OPS, NPS, and NW were obtained. In 73 patients, one or more viruses were detected by any of the three methods. Among all viruses, the sensitivity of NPS was significantly higher than that of NW (74% vs. 49%, respectively; p < 0.01) and OPS (74% vs. 49%, respectively; p < 0.01).ConclusionsFlocked NPS collection may be the most effective alternative to NW and OPS for detection of respiratory viruses in adults with acute pharyngitis using TaqMan real-time polymerase chain reaction.

The epidemiology and severity of respiratory viral infections in a tropical country: Ecuador, 2009–2016

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Cellular DNA quantification in respiratory samples for the normalization of viral load: a real need?

“…Nevertheless, the collection and storage of respiratory samples remain critical steps in the diagnostic workflow. The flocked swab together with its specific transport medium is increasingly recognized as a valid alternative to commonly used specimen collection methods such as nasopharyngeal aspiration [12,13]. The main objectives of the present study were to measure the cellularity of mid-turbinate flocked nasal swab samples with wellcharacterized viral respiratory infections and to assess the validity of viral load normalization based on the median number of cells measured.…”

Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections

“…Lower respiratory tract specimens such as sputum, bronchoalveolar lavage/wash, and lung tissue may be considered in cases where the patient may be infected with an emerging pathogen (173,174) or is under intensive/critical care for pneumonia (175), in cases involving autopsy (176), or where molecular detection requires pathological evidence of invasive disease (e.g., ADV infection in lung specimens of lung transplant patients) (177). In severe illness due to influenza and emerging pathogens, upper respiratory (372)(373)(374). b ϩϩϩ, specimen type has high detection rates for the indicated virus; ϩϩ, specimen type is acceptable for viral detection, but sensitivity may be reduced due to the sampling or testing method used for detection; ϩ, specimen type has reduced sensitivity for indicated virus; ϩϩ(ϩ), minor reduction; ϩ(ϩ), moderate reduction; o, limited utility.…”