Apr 02 Diagnosis of the Coronavirus disease (COVID-19): rRT-PCR or CT?
Chunqin Long, Huaxiang Xu, Qinglin Shen, Xianghai Zhang, Bing Fan, Chuanhong Wang, Bingliang Zeng, Zicong Li, Xiaofen Li, Honglu Li
ABSTRACT
Objective: To evaluate the diagnostic value of computed tomography (CT) and real-time polymerase chain reaction (rRT-PCR) for COVID-19 pneumonia.
Methods: This retrospective study included all patients with suspected COVID-19 pneumonia, who were examined by CT and rRT-PCR at initial presentation. The sensitivities of both tests were then compared. For patients with a confirmed final diagnosis, clinical and laboratory data were evaluated in addition to CT imaging findings.
Results: A total of 36 patients were finally diagnosed with COVID-19 pneumonia. Thirty-five patients had abnormal CT findings at presentation, while one patient had a normal CT scan. Using rRT-PCR, 30 patients tested positive, with 6 cases initially missed. Among these 6 patients, 3 became positive in the second round of rRT-PCR testing (after 2 days, 2 days and 3 days respectively), and the other 3 became positive only in the third round of rRT-PCR testing (after of 5 days, 6 days and 8 days respectively). At presentation, the sensitivity of CT was therefore 97,2%, while the sensitivity of initial rRT-PCR was only 83,3%.
Conclusion: rRT-PCR can produce initial false-negative results. We suggest that patients with typical CT findings but negative rRT-PCR results should be isolated, with rRT-PCR repeated to avoid misdiagnosis.