Abstract: Objective To explore the epidemiological, clinical and imaging characteristics of patients with novel coronavirus disease 2019 (COVID-19) in Tianjin. Methods The demographics, epidemiological, clinical data, laboratory tests and radiological characteristics of 135 COVID-19 patients hospitalized in Tianjin Haihe Hospital from January 21 to March 15, 2020 were retrospectively analyzed. The patients were divided into 2 groups according to the severity of illness: mild group (n=74) and severe group (n=61). The general data, clinical data and CT findings were compared between the two groups. Results In the 135 COVID-19 patients, 70 cases (51.9%) also had basic diseases. In the severe group, the comorbidity rate of arrhythmia was higher (P < 0.05), and the incidence rates of fever, fatigue, chest tightness and anorexia were higher (P < 0.05). There were 26 cases of cluster infection, involving 74 cases (54.8%). One hundred and twelve cases (83.0%) were confirmed by nucleic acid examination once. Among the 135 cases, 126 cases (93.3%) had symptoms at the time of onset, and the median time for nucleic acid to turn negative was 14 (10, 20) days. Nine cases (6.7%) were asymptomatic, with the median time 7.0 (5.5，13.0) days for nucleic acids shifted to the negative. Peripheral blood cells showed mainly lymphocyte decreased in 40 cases (29.6%), C-reactive protein (CRP) increased in 65 cases (48.1%), interleukin-6 increased in 57 cases (42.2%), D-dimer increased in 62 cases (45.9%), fibrinogen increased in 33 cases (24.4%), lactate dehydrogenase (LDH) increased in 36 cases (26.7%) and myoglobin increased in 9 cases (6.7%). Chest CT examination showed abnormalities in 127 cases (94.1%). The pathological changes were mainly distributed in the subpleural area in 122 cases (96.1%), among which ground glass density was the main manifestation in 106 cases (83.5%). In the severe group, bilateral lung involvement and the distribution of above 3 pulmonary lobes, ground glass and consolidation shadows were more common (all P <0.05). In most patients, the lesions can be absorbed by treatment, or a little fiber sliver was left. The 133 cases (98.5%) were eventually discharged after improvement, and 2 cases (1.5%) died. Conclusion The COVID- 19 in Tianjin area is mainly familial cluster, and most of them have basic diseases. The lymphocyte count is decreased obviously, and prognosis is favorable. Early chest CT examination can make up for the limitations of chest radiographs. It is recommended that chest CT examination and multiple nucleic acid tests of respiratory tract specimens should be carried out as soon as possible to achieve the early diagnosis and reduce missed diagnosis.

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