A case report of COVID-19 with false negative RT-PCR test: necessity of chest CT
Authors: Minli Lv
Jianquan Zhong
Yujian Liu
Hao Feng
Journal: Japanese Journal of Radiology (2020)
Discipline: CLINICAL MEDICINE
Keywords: COVID-19, 2019 corona virus disease; CT, computed tomography; CXR, chest radiography; RT-PCR, real-time fluorescence polymerase chain reaction.
Affiliations: Department of Radiology, Zigong First People's Hospital, Zigong, 643000, People's Republic of China., Zigong Infectious Disease Hospital, Zigong, 643000, People's Republic of China., Department of Radiology, Zigong First People's Hospital, Zigong, 643000, People's Republic of China. ., Zigong Infectious Disease Hospital, Zigong, 643000, People's Republic of China. .

Abstract:  The definite diagnosis of corona virus disease 2019 (COVID-19) is based on the viral isolation or positive result of polymerase chain reaction (PCR) from sputum, or nasal swab, or throat swab. However, the sensitivity to detect COVID-19 of real time (RT)-PCR is reported to be lower than that of chest CT. We report a case of 34-year-old man who was diagnosed as negative for COVID-19 based on the four sequential RT-PCR tests of his pharyngeal swab. Chest CT showed patchy ground-glass opacity on admission, and it rapidly progressed to segmental mixed consolidation and ground-glass opacity 3 days after admission, and it resolved in left upper lobe, but showed multifocal ground-glass opacities 7 days after admission, and they resolved within 2 weeks. The fifth RT-PCR test finally revealed positive results at the fifth day after admission. It is difficult to distinguish COVID-19 pneumonia from other viral pneumonia on CT findings alone; however, we emphasize the utility of chest CT to detect early change of COVID-19 in cases which RT-PCR tests show negative results. 

Retracted: No

PubPeer comments:
 Only two techniques were used in this study, one of them being RT-PCR. Despite this, no details appear for the protocol that was used. Could the authors kindly indicate whether the analyses were outsourced, and provide details of the RT-PCR protocol, including the primers used, and if they used any kits, the manufacturers and product numbers. , 
 #1 Dear Editors: We greatly appreciate the valuable comments from Dombeya Mupangae regarding the manuscript entitled u201cCOVID-19 patient with false negative RT-PCR testing: necessity of chest CTu201d (ID:u00a0RMED-D-D-20-0013). Following are our responses to the comments we made. Responds to comments: 1)RT-PCR testing The patient with suspected of novel coronavirus infection were underwent both chest CT imaging and laboratory virus nucleic acid test (RT-PCR assay with throat swab samples) at the Zigong Disease Control Center. The RT-PCR asssys were performed by using Wondfo (product numbers:Z-RR-0479-02-50) RT-PCR kits from Shanghai zhijiang Biotechnology Co., Ltd, which has approved use by the China Food and Drug Administration (CFDA). 2)Chest CT protocols All images were obtained by CT(SOMATOM go.Top, Siemens) with patients in supine position.The main scanning parameters were as follow:tube voltage=120kVp, automatic tube current modulation( 13-828mAs), pitch=0.35-1.5 mm, matrix=512u00d7512, slice thickness=10 mmuff0cfield of view=360 mmu00d7360 mm. All images were then reconstructed with a slice thickness of 0.6 mm with the same increment. ,