Influence and Control of SARS-CoV-2 Transmission under Two Different Models

SARS-CoV-2 is transmitted by contacting;however, the virus is so active that it can attach to objects and be transmitted from objects to humans via such contacting. The virus, which spreads through some living or inanimate-mediated processes, is more dangerous. On the basis of the routine contact transmission of infectious diseases, this paper further discusses the scope and efficiency of infectious diseases with indirect transmission. Through the study of two different transmission routes, the dynamic models of infectious diseases were constructed. The propagation of these two processes is theoretically studied using a differential equation model and stability analysis theory, and some actual virus propagation processes are simulated by numerical solutions. The prevention and control methods of infectious diseases are given, which lay the theoretical foundation for the discussion of related problems in practical application.

Prognostic significance of day-by-day in-hospital blood pressure variability in COVID-19 patients with hypertension.

Hypertension is the most common comorbidity in patients with coronavirus disease 2019 (COVID-19) and increases in-hospital mortality. Day-by-day blood pressure (BP) variability (BPV) is associated with clinical outcomes in hypertensive patients. However, little information is available on the association of BPV with the outcomes of COVID-19 patients with hypertension. This study aimed to demonstrate whether day-by-day in-hospital BPV had prognostic significance in these patients. The authors included 702 COVID-19 patients with hypertension from Huoshenshan Hospital (Wuhan, China), who underwent valid in-hospital BP measurements on at least seven consecutive days. Day-by-day BPV was assessed by standard deviation (SD), coefficient of variation (CV), and variation independent of mean (VIM). Overall, patients with severe COVID-19 and non-survivors had higher BPV than moderate cases and survivors, respectively. Additionally, higher BPV was correlated with greater age and higher levels of C-reactive protein, procalcitonin, high-sensitive cardiac troponin I, and B-type natriuretic peptide. In multivariable Cox regression, SD of systolic BP (SBP) was predictive of mortality [hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.05-1.30] as well as acute respiratory distress syndrome (ARDS) (HR 1.09, 95% CI 1.01-1.16). Similar trends were observed for CV and VIM of SBP, but not indices of diastolic BP variability. The authors demonstrated that day-by-day in-hospital SBP variability can independently predict mortality and ARDS in COVID-19 patients with hypertension. And high BPV might be correlated with severe inflammation and myocardial injury. Further studies are needed to clarify whether early reduction of BPV will improve the prognosis of these patients.

Correlation of hypocalcemia with poor prognosis of COVID-19 based on cox regression model: an analysis of 2 651 patients

ObjectiveTo investigate whether hypocalcemia is associated with poor prognosis in COVID-19 patients. MethodsA retrospective analysis was performed on 2 651 COVID-19 patients admitted to Wuhan Huoshenshan Hospital from February 4, 2020 to April 11, 2020. They were divided into low and normal calcium groups according to their serum calcium level lower than 2.11 mmol/L or not. Their basic demographic characteristics, results of laboratory tests, treatment, complications and outcomes were analyzed and compared between the 2 groups. COX regression model was used to analyze whether low calcium is an independent risk factors for poor outcomes in COVID-19 patients. ResultsThe low calcium group had significantly higher ratios of mechanical ventilation, extracorporeal membrane oxygenation (ECMO) and ICU occupancy (P<0.05);obviously higher incidences of sepsis, shock, hypoproteinemia, respiratory failure, coagulation disorders, acute kidney injury, acute myocardial injury, acute respiratory distress syndrome (ARDS), and even mortality (P<0.05);and remarkably longer length of hospital stay (P<0.001) when compared with the normal calcium group. The blood calcium level of mild and common, severe, and critical COVID-19 patients was 2.17 (2.11, 2.24), 2.13 (2.04, 2.21), and 2.03 (1.89, 2.18) mmol/L, respectively, and significant differences were seen among the patients (P<0.05). The calcium level was in a decreasing trend with the severity of COVID-19 (P<0.05). The calcium level was statistically lower in the dead patients than those survival [1.97 (1.87, 2.03) vs 2.17 (2.09, 2.23), P<0.001]. Multivariate Cox regression analysis indicated that serum calcium concentration <2.11 mmol/L was an independent risk factor for poor prognosis of COVID-19 (HR=5.695, 95%CI :2.363-13.725, P<0.001). ConclusionLow blood calcium level is an independent risk factor for poor prognosis in COVID-19 patients. Correction for hypocalcemia may be an important strategy to improve the prognosis of COVID-19 patients.

Sex Differences in the Incidence and Risk Factors of Myocardial Injury in COVID-19 Patients: A Retrospective Cohort Study.

Male novel coronavirus disease (COVID-19) patients tend to have poorer clinical outcomes than female patients, while the myocardial injury is strongly associated with COVID-19-related adverse events. Owing to a lack of corresponding data, we aimed to investigate the sex differences in the incidence of myocardial injury in COVID-19 patients and to identify the potential underlying mechanisms, which may partly account for the sex bias in the incidence of adverse events. This retrospective study included 1,157 COVID-19 patients who were hospitalized in Huoshenshan Hospital from 12 March 2020 to 11 April 2020. Data on the patients' demographic characteristics, initial symptoms, comorbidities and laboratory tests were collected. Totally, 571 (49.4%) female and 586 (50.6%) male COVID-19 patients were enrolled. The incidence of myocardial injury was higher among men than women (9.2 vs. 4.9%, p = 0.004). In the logistic regression analysis, age, and chronic kidney disease were associated with myocardial injury in both sexes. However, hypertension [odds ratio (OR) = 2.25, 95% confidence interval (CI) 1.20-4.22], coronary artery disease (OR = 2.46, 95% CI 1.14-5.34), leucocyte counts (OR = 3.13, 95% CI 1.24-7.86), hs-CRP (OR = 4.45, 95% CI 1.33-14.83), and D-dimer [OR = 3.93 (1.27-12.19), 95% CI 1.27-12.19] were independent risk factors only in the men. The correlations of hs-CRP and D-dimer with hs-cTnI and BNP were stronger in the men. The incidence of myocardial injury in COVID-19 patients is sex-dependent, predominantly in association with a greater degree of inflammation and coagulation disorders in men. Our findings can be used to improve the quality of clinical management in such settings.

Influence of blood pressure control and application of renin-angiotensin-aldosterone system inhibitors on the outcomes in COVID-19 patients with hypertension.

Hypertension is proved to be associated with severity and mortality in coronavirus disease 2019 (COVID-19). However, little is known about the effects of pre-admission and/or in-hospital antihypertension treatments on clinical outcomes. Thus, this study aimed to investigate the association between in-hospital blood pressure (BP) control and COVID-19-related outcomes and to compare the effects of different antihypertension treatments. This study included 2864 COVID-19 patients and 1628 were hypertensive. Patients were grouped according to their BP during hospitalization and records of medication application. Patients with higher BP showed worse cardiac and renal functions and clinical outcomes. After adjustment, subjects with pre-admission usage of renin-angiotensin-aldosterone system (RAAS) inhibitors (HR = 0.35, 95%CI 0.14-0.86, P = .022) had a lower risk of adverse clinical outcomes, including death, acute respiratory distress syndrome, respiratory failure, septic shock, mechanical ventilation, and intensive care unit admission. Particularly, hypertension patients receiving RAAS inhibitor treatment either before (HR = 0.35, 95%CI 0.13-0.97, P = .043) or after (HR = 0.18, 95%CI 0.04-0.86, P = .031) admission showed a significantly lower risk of adverse clinical outcomes than those receiving application of other antihypertensive medicines. Furthermore, consecutive application of RAAS inhibitors in COVID-19 patients with hypertension showed better clinical outcomes (HR = 0.10, 95%CI 0.01-0.83, P = .033) than non-RAAS inhibitors users. We revealed that COVID-19 patients with poor BP control during hospitalization had worse clinical outcomes. Compared with other antihypertension medicines, RAAS inhibitors were beneficial for improving clinical outcomes in COVID-19 patients with hypertension. Our findings provide direct evidence to support the administration of RAAS inhibitors to COVID-19 patients with hypertension before and after admission.