Analysis and Prediction of False Negative Results for SARS-CoV-2 Detection with Pharyngeal Swab Specimen in COVID-19 Patients: A Retrospective Study

Hui Xu; Li Yan; Chun (Martin) Qiu; Bo Jiao; Yanyan Chen; Xi Tan; Zhuo Chen; Ling Ai; Yaru Xiao; Ailin Luo; Shusheng Li

diagnosis relies on the nucleic acid test (rRT-PCR) of the virus. Recent studies reported that higher viral loads in the swab were detected soon after symptom onset (6, 7) . In the fever clinic of Tongji Hospital, we found that for many patients, whose CT images showed consolidations or A CT scan is critical in helping doctors diagnose COVID-19 patients as a clear destruction of the pulmonary parenchyma is a typical result (9, 10). In both the logistic regression and the AFT model, several CT imaging characteristics were found to play a key role in affecting test results. Specifically, both GGO and consolidation were identified as key characteristics, but they worked in an opposite manner. As mentioned above, some patients presented characteristic radiographic features of COVID-19 from the first scan, while the nucleic acid test result was falsely negative (11) . And then these patients were confirmed by positive repeat swab testing during the isolated observation or treatment. From our study, we found that there was a higher incidence rate of GGO in FNAC-P patients than in FNAC-N patients. GGO was the main radiological demonstration in the early stage of COVID-19 (12) , and the time windows depicted All rights reserved. No reuse allowed without permission. author/funder, who has granted medRxiv a license to display the preprint in perpetuity.