Comparison of nasopharyngeal swab and nasopharyngeal aspiration in adults for SARS‐CoV‐2 identification using reverse transcription‐polymerase chain reaction

Abstract

We aimed to compare reverse transcription‐polymerase chain reaction (RT‐PCR) results of nasopharyngeal aspiration (NA) and nasopharyngeal swab (NS) samples in the diagnosis of coronavirus disease 2019. NS was obtained with a dacron swab and NA was performed by aspiration cannula. The sampling was performed by an otolaryngologist to ensure standardized correct sampling from the nasopharynx. RT‐PCR was performed for the detection of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The level of agreement between the result of NA and NS samples for each patient was analyzed. The Ct values were compared. Thirty‐three patients were enrolled in the study with a mean age of 56.3 years. Thirteen subjects resulted negative with both NS and NA; 20 subjects resulted positive with NA and 18 subjects resulted positive with NS. The mean values of Ct for NA samples and NS samples were 24.6 ± 5.9 and 24 ± 6.7, respectively. There was no statistical difference between Ct values of NA and NS samples ( p = 0.48). RT‐PCR for SARS‐Cov2 performed with NA sample and NS sample showed a strong correlation regarding the positivity/negativity and the Ct values.

A Comparison of Pharyngeal Swabs and Tracheal Secretions for the Diagnosing of COVID-19

“…This finding is in line with our results, demonstrating 15.9% false negative oropharyngeal swabs. Furthermore, Ünsaler et al documented a great agreement between nasopharyngeal swab and nasopharyngeal aspiration RT-PCR testing for the detection of COVID-19 [ 16 ].…”

“…al. emphasized this clinical suspicion, demonstrating a great agreement in RT-PCR test results acquired from nasopharyngeal aspiration and nasopharyngeal swab collected simultaneously from hospitalized patients suspected with COVID-19 [ 16 ]. Another factor that contributes to a false-negative test result is the time point where the test is collected during the course of infection [ 21 , 22 ], because patients with suspected COVID-19 are likely in a later disease stage than patients without symptoms, and the abundance of discordant findings shown in Table 3 are related to patients registered with a COVID-19 diagnosis code.…”

Performance analysis among multiple fully automated anti-SARS-CoV-2 antibody measurement reagents: A potential indicator for the correlation of protection in the antibody titer

“…In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new coronavirus reported in Wuhan, posed a serious threat to global public health [ 1 , 2 ]. Currently, nucleic acid amplification tests and antigen tests are used for SARS-CoV-2 infection using nasopharyngeal swabs and saliva [ 3 ]; however, these tests may be affected by sample collection [ 4 ]. Alternatively, serological tests, which detect antibodies for pathogens in the blood, are expected to be useful for SARS-CoV-2 infection because they are less sensitive to sample collection and provide stable results [ 5 , 6 ].…”