The analysis of re-positive rate of throat swab nucleic acid test in ordinary patients with COVID-19

Objective To explore the incidence and possible factors of regaining positive after pharynx swab novel coronavirus (SARS-CoV-2) nucleic acid test in patients with common novel coronavirus pneumonia (COVID-19) during hospitalization.

Methods Throat swabs of 40 patients with common COVID-19 were collected from February 2, 2020 to March 10, 2020 in the East Hospital of Renmin Hospital of Wuhan University, and SARS-CoV-2 nucleic acid was detected by real-time reverse transcriptase polymerase chain reaction (RT-PCR).

Results After the first RT-PCR test was negative in all patients, 12 cases (30%) were positive in the second RT-PCR test, 13 cases (32.5%) were positive in the third time after two consecutive RT-PCR tests were negative, and 3 cases (7.5%) were positive in the fourth time in 3 consecutive RT-PCR test negative patients. Among the patients who were negative for 4 consecutive RT-PCR tests, 0 patients were positive for the fifth time.

Conclusions As an important indicator of diagnosis and discharge of COVID-19 patients, pharyngeal swab nucleic acid test has a certain false negative rate.