Multiple parameters required for diagnosis of COVID-19 in clinical practice
Authors: Pinggui Lei, Bing Fan, Jujiang Mao, Pingxian Wang
Journal: Journal of Infection (2020)

We read with interest the recent papers in this Journal by Hao who described clinical features of atypical 2019 novel coronavirus pneumonia with an initially negative RT-PCR assay.1Hao W. Clinical features of atypical 2019 novel coronavirus pneumonia with an initially negative RT-PCR assay.J Infect. 2020; https://doi.org/10.1016/j.jinf.2020.02.008Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar We would like to share our opinions for diagnostic approach of COVID-19 infection, the diagnostic approach for COVID-19 infection should be made comprehensive analysis. Since December 2019, a series of patients with unknown cause pneumonia had been reported in Wuhan of China. Recently, study on the early transmission dynamics had been reported that human-to-human was the epidemiologic characteristics for COVID-19 infection.2Li Q. Guan X. Wu P. Wang X. Zhou L. Tong Y. et al.Early transmission dynamics in Wuhan, china, of novel coronavirus-infected pneumonia.N Engl J Med. 2020; https://doi.org/10.1056/NEJMoa2001316Crossref Scopus (10588) Google Scholar Therefore, it is very essential to diagnose precisely the patients suspected with COVID-19 infection for opportune isolation or treatment. Chest CT and RT-PCR for detection of COVID-19 infection. Currently, the real-time reverse transcriptase polymerase chain reaction (RT-PCR) amplification of the viral DNA is considered as the "gold standard". However, initial RT-PCR is not always positive in the patients with COVID-19 infection.3Ai T. Yang Z. Hou H. Zhan C. Chen C. Lv W. et al.Correlation of chest CT and RT-PCR testing in coronavirus disease 2019 (COVID-19) in China: a report of 1014 cases.Radiology. 2020; 200642https://doi.org/10.1148/radiol.2020200642Crossref PubMed Scopus (3884) Google Scholar,4Fang Y. Zhang H. Xie J. Lin M. Ying L. Pang P. et al.Sensitivity of chest CT for COVID-19: comparison to RT-PCR.Radiology. 2020; 200432https://doi.org/10.1148/radiol.2020200432Crossref PubMed Scopus (2328) Google Scholar In that situation, chest computed tomographic (CT) images could be played an important role to detect the lesions in the pulmonary parenchyma in the patients suspected with COVID-19 infection. But it doesn't mean that the abnormalities of CT images could be observed in the COVID-19 infection while the initial RT-PCR is positive or negative. 3Ai T. Yang Z. Hou H. Zhan C. Chen C. Lv W. et al.Correlation of chest CT and RT-PCR testing in coronavirus disease 2019 (COVID-19) in China: a report of 1014 cases.Radiology. 2020; 200642https://doi.org/10.1148/radiol.2020200642Crossref PubMed Scopus (3884) Google Scholar, 4Fang Y. Zhang H. Xie J. Lin M. Ying L. Pang P. et al.Sensitivity of chest CT for COVID-19: comparison to RT-PCR.Radiology. 2020; 200432https://doi.org/10.1148/radiol.2020200432Crossref PubMed Scopus (2328) Google Scholar, 5Shi H. Han X. Jiang N. Cao Y. Alwalid O. Gu J. et al.Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, china: a descriptive study.Lancet Infect Dis. 2020; https://doi.org/10.1016/S1473-3099(20)30086-4Abstract Full Text Full Text PDF Scopus (2553) Google Scholar, 6Pan F. Ye T. Sun P. Gui S. Liang B. Li L. et al.Time course of lung changes on chest CT during recovery from 2019 novel coronavirus (COVID-19) pneumonia.Radiology. 2020; 200370https://doi.org/10.1148/radiol.2020200370Crossref PubMed Scopus (1847) Google Scholar Therefore, even though chest CT plays a key role in detection or diagnosis of COVID-19 infection, however, chest CT examination and RT-PCR results should be mutual verification for precise diagnosis in the patient suspected COVID-19 infection. Clinical characteristics. Beside CT examination results, initial symptoms were helpful in screening. For clinical manifestation, fever, dyspnea, chest tightness, cough, sputum, weakness, vomiting, diarrhea, etc. were observed in the patients with COVID-19 infection.5Shi H. Han X. Jiang N. Cao Y. Alwalid O. Gu J. et al.Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, china: a descriptive study.Lancet Infect Dis. 2020; https://doi.org/10.1016/S1473-3099(20)30086-4Abstract Full Text Full Text PDF Scopus (2553) Google Scholar,7Guan W.J. Ni Z.Y. Hu Y. Liang W.H. Ou C.Q. He J.X. et al.Clinical characteristics of coronavirus disease 2019 in China.N Engl J Med. 2020; https://doi.org/10.1056/NEJMoa2002032Crossref Scopus (20088) Google Scholar Of these clinical characteristics, fever and cough were the most frequency percentage of initial symptoms, and the other manifestations should be taken consideration. Laboratory results. Laboratory results were considered as auxiliary information to diagnose COVID-19 infection.5Shi H. Han X. Jiang N. Cao Y. Alwalid O. Gu J. et al.Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, china: a descriptive study.Lancet Infect Dis. 2020; https://doi.org/10.1016/S1473-3099(20)30086-4Abstract Full Text Full Text PDF Scopus (2553) Google Scholar,7Guan W.J. Ni Z.Y. Hu Y. Liang W.H. Ou C.Q. He J.X. et al.Clinical characteristics of coronavirus disease 2019 in China.N Engl J Med. 2020; https://doi.org/10.1056/NEJMoa2002032Crossref Scopus (20088) Google Scholar In our hospital, there were 14 cases confirmed COVID-19 infection. Of 14 patients, white-cell count was tended to be normal in 12 patients (85.71%), lymphocyte (8/14, 57.14%) and monocyte (9/14, 64.29%) percentage had a tendency to decrease. Significant statistical differences were observed in lymphocyte percentage decreased and C-reactive protein elevated (all P = 0.015) in the patients with COVID-19 infection between initial positive chest CT results (10/14) and negative chest CT results (4/14). Thus, knowing these clinical laboratory results was helpful for the doctor to diagnose the current novel coronavirus infection. Exposure history. Recent studies reported that most of the patients with COVID-19 infection had the exposure history to the source of transmission within past 14 days. Approximately 13 patients (2%) had the history of direct contact with wildlife, 75% cases in the epidemic area or contact with resident of epidemic area.5Shi H. Han X. Jiang N. Cao Y. Alwalid O. Gu J. et al.Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, china: a descriptive study.Lancet Infect Dis. 2020; https://doi.org/10.1016/S1473-3099(20)30086-4Abstract Full Text Full Text PDF Scopus (2553) Google Scholar,7Guan W.J. Ni Z.Y. Hu Y. Liang W.H. Ou C.Q. He J.X. et al.Clinical characteristics of coronavirus disease 2019 in China.N Engl J Med. 2020; https://doi.org/10.1056/NEJMoa2002032Crossref Scopus (20088) Google Scholar However, 28 cases (35%) with COVID-19 infections were no obvious history of exposure,5Shi H. Han X. Jiang N. Cao Y. Alwalid O. Gu J. et al.Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, china: a descriptive study.Lancet Infect Dis. 2020; https://doi.org/10.1016/S1473-3099(20)30086-4Abstract Full Text Full Text PDF Scopus (2553) Google Scholar which needs to pay more attention in this situation. In conclusion, even though chest CT has played a key role in detection or diagnosis of COVID-19 infection with some typical CT features while the initial RT-PCR result is negative. However, not all the cases had the initial abnormality chest CT results or positive RT-PCR in the patients with COVID-19 infection. Consequently, RT-PCR results, chest CT features, clinical manifestation, laboratory results, and exposure history should be made a comprehensive analysis to diagnose COVID-19 infection for the clinical decisions beyond clinical and radiological features.