Evaluation of Pulmonary Edema Using Ultrasound Imaging in Patients With COVID-19 Pneumonia Based on a Non-local Channel Attention ResNet.

Recent research has revealed that COVID-19 pneumonia is often accompanied by pulmonary edema. Pulmonary edema is a manifestation of acute lung injury (ALI), and may progress to hypoxemia and potentially acute respiratory distress syndrome (ARDS), which have higher mortality. Precise classification of the degree of pulmonary edema in patients is of great significance in choosing a treatment plan and improving the chance of survival. Here we propose a deep learning neural network named Non-local Channel Attention ResNet to analyze the lung ultrasound images and automatically score the degree of pulmonary edema of patients with COVID-19 pneumonia. The proposed method was designed by combining the ResNet with the non-local module and the channel attention mechanism. The non-local module was used to extract the information on characteristics of A-lines and B-lines, on the basis of which the degree of pulmonary edema could be defined. The channel attention mechanism was used to assign weights to decisive channels. The data set contains 2220 lung ultrasound images provided by Huoshenshan Hospital, Wuhan, China, of which 2062 effective images with accurate scores assigned by two experienced clinicians were used in the experiment. The experimental results indicated that our method achieved high accuracy in classifying the degree of pulmonary edema in patients with COVID-19 pneumonia by comparison with previous deep learning methods, indicating its potential to monitor patients with COVID-19 pneumonia.

Reevaluation of Seroprevalence using a Semi-quantitative Anti-spike IgG in Health Care workers at an Academic Medical Center in Boston, Massachusetts (preprint)

Background Accurate measurement of antibodies is a necessary tool for assessing exposure to SARS-CoV-2 and facilitating understanding of the role of antibodies in immunity. Most assays are qualitative in nature and employ a threshold to determine presence of antibodies. Semi-quantitative assays are now available. Here we evaluate the semi-quantitative SARS-CoV-2 IgG II (anti-spike (S)) assay. We aim to reassess the seroprevalence using anti-S assay and subsequently compare it to the previously measured IgG (anti-nucleoprotein (N)) in health care workers at an academic medical center in Boston. Methods 1743 serum samples from HCWs at Boston Medical Center were analyzed for SARS-CoV-2 anti-S IgG and IgM using the Abbott SARS-CoV-2 IgG II and□Abbott AdviseDx□SARS-CoV-2 IgM assay, respectively. Precision, linearity, positive and negative concordance with prior RT-PCR test were evaluated for anti-S IgG. Seroprevalence and its association with demographics variables was also assessed. Results Linearity and precision results were clinically acceptable. The positive and negative concordance for anti-S IgG with RT-PCR was 88.2% (95% CI: 79.4% - 94.2%) and 97.43% (95% CI: 95.2% - 98.8%), respectively. Overall, 126 (7.2%) of 1,743 participants were positive by anti-S IgG. Among the 1302 participants with no prior RT-PCR, 40 (3.1%) were positive for anti-S IgG antibody. The original agreement in this population with the qualitative, anti-N IgG assay was 70.6%. Upon optimizing the threshold from 1.4 to 0.49 S/CO of the anti-N IgG assay, the positive agreement of the assay increases to 84.7%. Conclusion The anti-S IgG assay demonstrated reproducible and reliable measurements. This study highlights the presence of asymptomatic transmission among individuals with no prior history of positive RT-PCR. It also highlights the need for optimizing thresholds of the qualitative SARS-CoV-2 IgG assay for better agreement between assays by the same vendor.

Successful treatment of a critically ill patient with COVID-19 using tocilizumab and human umbilical cord mesenchymal stem cells: a case report (preprint)

Background A worldwide outbreak of coronavirus disease 2019 (COVID-19) has drawn global attention. However, up to now, no standard and effective therapy are available. Case presentation A 62-year-old man with a history of hypertension and diabetes was diagnosed with COVID-19 pneumonia. He suffered from obvious shortness of breath and severe hyoxemia. Normal treatments like supportive therapy and antiviral drugs didn’t seem to improve his conditions. Then, he was given tocilizumab and human umbilical cord mesenchymal stem cells. After that, his respiratory symptoms and lung infectious lesions gradually subsided, and he was successfully discharged eventually. Conclusions For critically ill COVID-19 patients, immunological treatment like tocilizumab human umbilical cord mesenchymal stem cells should be considered.

Clinical features and outcomes of pregnant women with COVID-19: a systematic review and meta-analysis (preprint)

Background: COVID-19 outbreak in Wuhan, China recently. It quickly spread throughout worldwide. In this study, we systematically reviewed the clinical features and outcomes of pregnant women with COVID-19.Methods: PubMed、Web of Science、EMBASE、MEDLINE were searched from January 1, 2020 to April 16, 2020. Case review of pregnant women infected with COVID-19 were included. Two reviewers screened 366 literatures and 14 studies included, four reviewers independently extracted the features of the literatures. We used random-effects model to analyze incidence (P) and 95% confidence interval (95%CI). Heterogeneity was assessed using the I2 statistic.Results: The meta- analysis included 236 pregnant women with COVID-19. The results were as follows: positive CT findings (71%; 95%CI, 0.49~0.93), cesarean section (65%; 95%CI, 0.42~0.87), fever (51%; 95%CI, 0.35~0.67), lymphopenia (49%; 95%CI, 0.29~0.70), coexisting disorders (33%; 95%CI, 0.21~0.44), cough (31%; 95%CI, 0.23~0.39), fetal distress (29%; 95%CI, 0.08~0.49), preterm labor (23%; 95%CI, 0.14~0.32), severe case or death (12%; 95%CI, 0.03~0.20). The subgroup analysis showed compared with nonpregnant patients, pregnant women with COVID-19 had significantly lower incidences of fever (pregnant women group, 51%; nonpregnant patients group, 91%; P＜0.00001) and cough (pregnant women group, 31%; nonpregnant patients group, 67%; P＜0.0001). Conclusions: The incidence of fever, cough and positive CT findings in pregnant women with COVID-19 is less than that in the general population, preterm labor is the opposite. There is no evidence that COVID-19 can propagate vertically for the time being.