Analysis of 2019-nCoV Infection and Clinical Manifestations of Outpatients: An Epidemiological Study from the Fever Clinic in Wuhan, China

Abstract

Background: Since the outbreak of 2019 novel coronavirus (2019-nCoV) pneumonia, thousands of patients with fever, cough or fatigue were flocked to department of fever outpatients of designated hospitals in Wuhan, China, everyday. To date, no data have been provided to reflect the prevalence of Corona Virus Disease 2019 (COVID-19) among these outpatients. Besides, little is known on the distinguishable clinical features between COVID-19 and nucleic acid negative patients in fever clinics. Methods: From January 30 to February 4, 2020, a retrospective study was conducted on 936 patients from the fever clinic of Tongji Hospital, the biggest third-level grade-A hospital in Wuhan, which is located in the worst affected area by 2019-nCoV. The infectious status of 2019-nCoV was estimated among the outpatients in the fever clinics. The epidemiological and clinical characteristics were compared between COVID-19 and nucleic acid negative patients. Findings: From January 30 to February 4 of 2020, 628 (67·1%) of 936 fever outpatients in Tongji Hospital were diagnosed as COVID-19. The average age of 628 COVID-19 patients (53 years ±14·8 years) was obviously older than that of nucleic acid negative patients (49 years ±13·0 years) (P < 0·01). Of the 628 patients diagnosed with COVID-19, 553 cases were mild (88·1%) while 75 cases including severe and critical patients were severe (11·5%). Fever (78·2%) was the predominant initial symptom in COVID-19 patients, followed by cough (15·6%). The highest nucleic acid detection rate for 2019-nCoV infection was observed in patients with muscle ache (80·0%, 95% CI: 45·9-95·0), followed by dyspnea (75·0%, 95% CI: 37·7-93·7). Among 936 patients, Chest CT scans were performed on 780 patients, 511 of whom were diagnosed with COVID-19. Of the 511 COVID-19 patients, 492 (96·3%) cases reported positive chest CT, which was significantly higher than those with nucleic acid negative patients (88·5%, 238/269, P<0·001). Among all 936 visitors, 460 of them conducted routine blood tests, and 309 were COVID-19 patients. Significantly lower number of eosinophils was characterized in COVID-19 patients as compared to that of nucleic acid negative patients (0·02×109/L vs. 0·03×109/L; P=0·002). The ROC curve of the model (2019-nCoV nucleic acid test result prediction) was constrated by fever, chest CT bilateral pulmonary and ground-glass opacity and eosinophils count below normal level. We observed fever plus bilateral lung ground-glass opacity and eosinophils count below normal level in blood routine had significant clinical value, and the coincidence rate of diagnosis with the COVID-19 was up to 79·8% (95%CI: 71·9-87·7). And the second combination of clinical significance was bilateral lung ground-glass opacity and eosinophils count below normal, which was 77·0% (95%CI: 71·0-83·0). Interpretation: The infection rate of 2019-nCoV in the outpatients from the fever clinics was high and the majority of COVID-19 were mild cases. The highest nucleic acid detection rate for 2019-nCoV infection was observed in patients with muscle ache, followed by dyspnea. The combination of fever, lower accounts of eosinophils and the imaging features of ground-glass opacity in bilateral lungs might be a valuable indicator for 2019-nCoV infection. Funding Statement: This study was supported by the National Natural Science Foundation of China [Grants 81874149, 81974456]; the Clinical Research Physician Program of Tongji Medical College; the Huazhong University of Science and Technology [Grant 5001540075]. Declaration of Interests: All authors declare no competing interests. Ethics Approval Statement: The study was approved by the Ethical Committee of the Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology Wuhan, Hubei China.