ABSTRACT
Based on the characteristic of the COVID-19 asymptomatic infection, and due to the shortage of traditional mathematical models of transmission dynamics of infectious diseases, we propose a new SAIR model. This SAIR model fully considers the infectious characteristics of asymptomatic cases and the transformation characteristics between the four kinds case. According to the data released by the National Health Commission of P.R.C, the model parameters are calculated, and the transmission process of the COVID-19 is simulated dynamically. It is found that the SAIR model data are in good agreement with the actual data, and the time characteristics of the infection rate are particularly accurate, proving the accuracy and effectiveness of the model. Then, on the basis of the differences between the model data and the real data, the standard deviation of the error is calculated. From the standard deviation, the functional intervals of the confirmed infection rate and the asymptomatic infection rate, the interval of the total number of cases in the model, and the interval of the number of asymptomatic cases in the society are also calculated. The number of asymptomatic cases in society is of important and realistic significance for the assessment of risk and subsequent control measures. Then, according to the dynamic simulation data of the model with changed value of parameters, the remarkable effects of strict quarantines are discussed. Finally, the possible direction of further study is given.
ABSTRACT
Background: Coronavirus disease-2019 (COVID-19) caused by SARS-CoV-2 is a rapidly escalating epidemic in most of countries. Symptom of COVID-19 usually present as the normal or decrease of leucocytes and the decrease of lymphocytes, which may be the body’s response for SARS-CoV-2 infection. However, it is unknown that whether rising leukocytes, especially neutrophils, will aggravate lung injury in COVID-19. Here we report a case of aggravated lung injury induced by rising neutrophils with the usage of recombinant human granulocyte stimulating factor (GSF) for the first time.Case presentation: A patient aged 46 years old was infected with SARS-CoV-2 without hypoxemia on admission, but his leucocytes decreased gradually after admission. After following injected with recombinant human granulocyte stimulating factor(GSF) 150 μg , the absolute value of leucocytes reached to 32.81×109 /L, and neutrophils were 31.57×109/L. Then, the patient’s condition deteriorated rapidly and he appeared a series of symptoms, such as short breath, hemoptysis, hypoxemia, increased range of lung lesions and secondary acute respiratory distress syndrome (ARDS). However, those symptoms were alleviated and leucocytes recover to normal level gradually after stopping recombinant human GSF treatment. Eventually, Re-examination of CT showed that lung lesions were absorbed significantly and he was cured and discharged from hospital.Conclusion: This case report showed that iatrogenic increase of leucocytes (especially neutrophils) may worsen lung injury and leucocyte increasing agents were used with caution in the early stage of COVID-19 patients. At the same time, the phenomenon remains to be further confirmed in the future study.
Subject(s)
Lung Diseases , Iatrogenic Disease , Respiratory Distress Syndrome , Dyspnea , Hypoxia , COVID-19ABSTRACT
Objective: To analyze the clinical characteristics of patients with novel coronavirus pneumonia in Kunming City, and to study the correlation between nutritional status and immune function. Methods: Clinical data of 36 patients with novel coronavirus pneumonia in isolation area of Kunming Third People's Hospital from January 31 to February 15, 2020 were collected, and the basic situation, clinical characteristics, laboratory examination and CT imaging characteristics were analyzed. Serum albumin (ALB), prealbumin (PAB), hypersensitive c-reactive protein (hs-crp), CD3T cells, CD4T cells, CD8T cells and normal control group were analyzed. A simple linear regression analysis of the relationship between proalbumin and T cell subpopulation counts in the blood of patients. Results: (1) The patients with new coronavirus pneumonia in Kunming were mainly of common type. (2) 50% of the patients' first symptoms were fever and cough; (3) The total number of white blood cells in peripheral blood was normal or decreased in 23 cases (79%), and the lymphocyte count decreased in 5 cases (13.89%), without anemia. Hypersensitive c-reactive protein increased in 19 (52.78%) cases, and procalcitonin increased in 1 case. Albumin decreased in 5 cases (13.89%), proalbumin decreased in 15 cases (41.67%), alanine transaminase increased slightly in 4 cases (11.11%), alanine transaminase increased slightly in 4 cases (11.11%), total bilirubin increased slightly in 11 cases (30.56%), and renal function and blood coagulation were normal. Absolute value of CD3+T cells is with a decrease in 21 cases (58.3%), CD4+T in 28 cases (77.8%), CD8+T in 17 cases (47.2%), and CD4+/ CD8+ inverse in 6 cases (16.7%). (4) The prealbumin, CD3 T cells, CD4 T cells and CD8 T cells in the new coronavirus pneumonia group were significantly lower than those in the normal control group, and the hypersensitive c-reactive protein was higher than that in the normal control group. (5) The levels of PAB in the serum of the patients were linearly correlated with hs-crp, CD3 T cells, CD4 T cells and CD8 T cells, and the correlation coefficients were -0.474, 0.558, 0.467 and 0.613, respectively, showing statistical differences. Conclusion: The clinical characteristics of the novel coronavirus pneumonia in Kunming are different from those in Wuhan. The changes of serum proalbumin and T cell subsets are relatively obvious. Changes in serum proalbumin may contribute to the early warning of novel coronavirus pneumonia. The nutritional status of patients with common and mild pneumonia should be considered.