Epidemiological characteristics of close contacts of coronavirus disease 2019 in the early stage in Chongqing

Objective: To investigate the epidemiological Characteristics and risk factors of close contacts of coronavirus disease 2019(COVID-19).

Single-Cell Analysis Reveals Macrophage-Driven T Cell Dysfunction in Severe COVID-19 Patients (preprint)

The vastly spreading COVID-19 pneumonia is caused by SARS-CoV-2. Lymphopenia and cytokine levels are tightly associated with disease severity. However, virus-induced immune dysregulation at cellular and molecular levels remains largely undefined. Here, the leukocytes in the pleural effusion, sputum, and peripheral blood biopsies from severe and mild patients were analyzed at single-cell resolution. Drastic T cell hyperactivation accompanying elevated T cell exhaustion was observed, predominantly in pleural effusion. The mechanistic investigation identified a group of CD14+ monocytes and macrophages highly expressing CD163 and MRC1 in the biopsies from severe patients, suggesting M2 macrophage polarization. These M2-like cells exhibited up-regulated IL10, CCL18, APOE, CSF1 (M-CSF), and CCL2 signaling pathways. Further, SARS-CoV-2-specific T cells were observed in pleural effusion earlier than in peripheral blood. Together, our results suggest that severe SARS-CoV-2 infection causes immune dysregulation by inducing M2 polarization and subsequent T cell exhaustion. This study improves our understanding of COVID-19 pathogenesis.

CT differential diagnosis of COVID-19 and non-COVID-19 in symptomatic suspects: a practical scoring method (preprint)

Background Although typical and atypical CT image findings of COVID-19 are reported in current studies, the CT image features of COVID-19 overlap with those of viral pneumonia and other respiratory diseases. Hence, it is difficult to make an exclusive diagnosis.Methods Thirty confirmed cases of COVID-19 and forty-three cases of other aetiology or clinically confirmed non-COVID-19 in a general hospital were included. The clinical data including age, sex, exposure history, laboratory parameters and aetiological diagnosis of all patients were collected. Seven positive signs (posterior part/lower lobe predilection, bilateral involvement, rounded GGO, subpleural bandlike GGO, crazy-paving pattern, peripheral distribution, and GGO +/- consolidation) from significant COVID-19 CT image features and four negative signs (only one lobe involvement, only central distribution, tree-in-bud sign, and bronchial wall thickening) from other non-COVID-19 pneumonia were used. The scoring analysis of CT features was compared between the two groups (COVID-19 and non-COVID-19).Results Older age, symptoms of diarrhoea, exposure history related to Wuhan, and a lower white blood cell and lymphocyte count were significantly suggestive of COVID-19 rather than non-COVID-19 (p<0.05). The receiver operating characteristic (ROC) curve of the combined CT image features analysis revealed that the area under the curve (AUC) of the scoring system was 0.854. These cut-off values yielded a sensitivity of 56.67% and a specificity of 95.35% for a score>4, a sensitivity of 100% and a specificity of 23.26% for a score>0, and a sensitivity of 86.67% and a specificity of 67.44% for a score>2.Conclusions With a simple and practical scoring system based on CT imaging features, we can make a hierarchical diagnosis of COVID-19 and non-COVID-19 with different management suggestions.

Experience of treating severe cases of 2019 novel coronavirus pneumonia in Changde area / 中华危重病急救医学

Since the cluster of the 2019 novel coronavirus (2019-nCoV) pneumonia, a large number of patients gathered, the mortality of critical patients has remained high and the treatment was unclear. In this outbreak, Hunan Changde region immediately set up a hospital and intensive care unit. The patients relieved through respiratory support, hemodynamics management, nutritional support, the application of antiviral drugs, analgesic and sedation. The treatment experience in severe cases of 2019-nCov pneumonia patients were summarized as follows: in terms of respiratory support, we needed to pay attention to the advantages of high-flow nasal cannula oxygen therapy (HFNC) and the intervention of mechanical ventilation, pay attention to the ventilator parameters, and adopt prone position timely. In the aspects of fluid resuscitation and volume management, we should pay attention to the characteristics of severe patients' volume status, perform early evaluation, and clinicians should focused on hemodynamic management beside the bed. In the aspect of nutritional support and evaluation and maintenance of intestinal function, early enteral nutrition should be adopted in time. However, the trade-off between the risk of intestinal function and nutritional support in patients with mechanical ventilation and the antiviral benefits of Kaletra needed to be reevaluated, the optimized way of analgesia and sedation was adopted, at the same time, the usage and side effects of antiviral drugs should be paid attention to. We should grasp the opportunity of transportation for severe patients. It is suggested that some warning scores should be used to facilitate early recognition of patients with severe infection and then they should be earlier transferred to the designated hospital for intensive care.