Spatial interpolation of regional PM2.5 concentrations in China during COVID-19 incorporating multivariate data.

During specific periods when the PM2.5 variation pattern is unusual, such as during the coronavirus disease 2019 (COVID-19) outbreak, epidemic PM2.5 regional interpolation models have been relatively little investigated, and little consideration has been given to the residuals of optimized models and changes in model interpolation accuracy for the PM2.5 concentration under the influence of epidemic phenomena. Therefore, this paper mainly introduces four interpolation methods (kriging, empirical Bayesian kriging, tensor spline function and complete regular spline function), constructs geographically weighted regression (GWR) models of the PM2.5 concentration in Chinese regions for the periods from January-June 2019 and January-June 2020 by considering multiple factors, and optimizes the GWR regression residuals using these four interpolation methods, thus achieving the purpose of enhancing the model accuracy. The PM2.5 concentrations in many regions of China showed a downward trend during the same period before and after the COVID-19 outbreak. Atmospheric pollutants, meteorological factors, elevation, zenith wet delay (ZWD), normalized difference vegetation index (NDVI) and population maintained a certain relationship with the PM2.5 concentration in terms of linear spatial relationships, which could explain why the PM2.5 concentration changed to a certain extent. By evaluating the model accuracy from two perspectives, i.e., the overall interpolation effect and the validation set interpolation effect, the results showed that all four interpolation methods could improve the numerical accuracy of GWR to different degrees, among which the tensor spline function and the fully regular spline function achieved the most stable effect on the correction of GWR residuals, followed by kriging and empirical Bayesian kriging.

SARS-CoV-2 Causes Acute Kidney Injury by Directly Infecting Renal Tubules.

Acute kidney injury (AKI) is one of the most prevalent complications among hospitalized coronavirus disease 2019 (COVID-19) patients. Here, we aim to investigate the causes, risk factors, and outcomes of AKI in COVID-19 patients. We found that angiotensin-converting enzyme II (ACE2) and transmembrane protease serine 2 (TMPRSS2) were mainly expressed by different cell types in the human kidney. However, in autopsy kidney samples, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein was detected in ACE2+ or TMPRSS2+ renal tubular cells, whereas the RNAscope® Assay targeting the SARS-CoV-2 Spike gene was positive mainly in the distal tubular cells and seldom in the proximal tubular cells. In addition, the TMPRSS2 and kidney injury marker protein levels were significantly higher in the SARS-CoV-2-infected renal distal tubular cells, indicating that SARS-CoV-2-mediated AKI mainly occurred in the renal distal tubular cells. Subsequently, a cohort analysis of 722 patients with COVID-19 demonstrated that AKI was significantly related to more serious disease stages and poor prognosis of COVID-19 patients. The progressive increase of blood urea nitrogen (BUN) level during the course of COVID-19 suggests that the patient's condition is aggravated. These results will greatly increase the current understanding of SARS-CoV-2 infection.

Clinical Characteristics of Patients with Severe and Critical COVID-19 in Wuhan: A Single-Center, Retrospective Study.

INTRODUCTION: This retrospective, single-center study was performed to systemically describe the characteristics and outcomes of patients with severe and critical coronavirus disease 2019 (COVID-19) in Wuhan, analyze the risk factors, and propose suggestions for clinical diagnosis and treatment to guide the subsequent clinical practice. METHODS: A total of 753 consecutive patients with COVID-19 admitted to the West Campus of Wuhan Union Hospital from January 22, 2020 to May 7, 2020 were enrolled in this study. Demographic, clinical, laboratory, and outcome data were extracted from the electronic medical records of Wuhan Union Hospital and were exhaustively analyzed using R (version 3.6.1). RESULTS: A total of 493 severe and 228 critical cases out of 753 COVID-19 cases were considered in this study. Among the critical cases, the death rate was 79.4%, and age was a risk factor for death. Compared to the severe disease group, the critical disease group had higher white blood cell (WBC) and neutrophil counts and a decreased lymphocyte count at admission. Compared to early death cases (death within 1 week after admission), a more prolonged course of the disease was associated with a higher risk of hypoproteinemia, liver injury, thrombocytopenia, anemia, disseminated intravascular coagulation (DIC), coagulation disorders, acute kidney injury (AKI), and infection. Higher creatine kinase (CK) and lactate dehydrogenase (LDH) levels were related to early death events, but univariate and multivariate analyses confirmed only LDH as an independent predictor of early death. Notably, anticoagulation therapy was associated with an improved prognosis of critical cases in this cohort. CONCLUSION: Our results showed large differences between patients with severe and critical COVID-19. During the course of COVID-19 in the critical disease group, the incidence of hypoproteinemia, anemia, thrombocytopenia, and coagulation disorders increased significantly, which highlighted the importance of medical care in the first week after admission. LDH could act as an independent predictor of early death in critical cases, and anticoagulation therapy was correlated with an improved prognosis of patients with critical COVID-19.

Pit latrines may be a potential risk in rural China and low-income countries when dealing with COVID-19.

According to the latest reports, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which caused coronavirus disease 2019 (COVID-19), was successfully isolated from the excreta (stool and urine) of COVID-19 patients, suggesting SARS-CoV-2 could be transmitted through excreta contaminated water. As pit latrines and the use of untreated excreta as fertilizer were common in rural China, we surveyed 27 villages of Jiangxi and Hubei provinces and found that pit latrines could be a potential source of SARS-CoV-2 water pollution. Recently, bats have been widely recognized as the source of SARS-CoV-2. There were many possible intermediate hosts of SARS-CoV-2, including pangolin, snake, bird and fish, but which one was still not clear exactly. Here, we proposed a hypothesis to illustrate the mechanism that SARS-CoV-2 might spread from the excreta of infected humans in pit latrines to potential animal hosts, thus becoming a sustainable source of infection in rural China. Therefore, we believe that abolishing pit latrines and banning the use of untreated excreta as fertilizer can improve the local living environment and effectively prevent COVID-19 and other potential waterborne diseases that could emanate from the excreta of infected persons. Although this study focused on rural areas in China, the results could also be applied to low-income countries, especially in Africa.

Differences of inflammatory and non-inflammatory indicators in Coronavirus disease-19 (COVID-19) with different severity.

Background A variety of inflammatory and non-inflammatory indicators were increased in severe and critical Coronavirus disease-19 (COVID-19) and some of them were used to evaluate the severity and predict prognosis of community-acquired pneumonia. The aim of this study was to investigate the association of these indicators in COVID-19 with different severity. Methods Clinical data of 46 patients with severe COVID-19 and 31 patients with critical COVID-19 were collected. The general characteristics and comorbidities of the patients were retrospectively analyzed. The initial and peak concentrations of serum troponin I (cTnI), D-dimer (D-D), C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), initial and peak neutrophil counts and initial and trough lymphocyte counts were compared between two groups. The correlation between the variation of cTnI, D-D, CRP, IL-6, PCT, neutrophils, lymphocytes and the severity of the disease was analyzed. The efficacy of the initial concentrations of cTnI, D-D, CRP, IL-6, PCT, the initial neutrophil and lymphocyte counts in predicting critical COVID-19 were evaluated by receiver operating characteristic (ROC) curve. Results The initial and peak concentrations of cTnI, D-D, CRP, IL-6, PCT, initial and peak neutrophil counts in critical group were higher than those in severe group, the initial and trough counts of lymphocyte were lower than those in the severe group. Except for the initial level of PCT, the other differences were statistically significant (p < 0.05). The increase of cTnI, D-D, CRP, IL-6, PCT, neutrophils and the decrease of lymphocytes were related to the severity of the disease, OR values were 28.80, 2.20, 18.47, 10.80, 52.00, 9.60 and 21.08, respectively. Except for D-D, the other differences were statistically significant. The areas under ROC curves for predicting critical COVID-19 by initial concentrations of cTnI, D-D, CRP, IL-6, PCT, initial lymphocyte and neutrophil counts were 0.76, 0.78, 0.83, 0.95, 0.56, 0.68 and 0.62, respectively. Conclusions The severe and critical COVID-19 patients had significant differences in concentrations of serum cTnI, D-D, CRP, IL-6, PCT, neutrophil and lymphocyte counts. The increase of cTnI, CRP, IL-6, PCT, neutrophils and decrease of lymphocytes indicated severe condition. The initial IL-6 might be a good indicator of COVID-19 severity.