【Objective】 To describe the epidemiological features of COVID-19 confirmed cases in Northwest China and discuss the causation of these features in order to provide reference for taking preventive measures in the future. 【Methods】 We collected the data of all confirmed COVID-19 cases from January 23, 2020 to March 17, 2020 released on the official website of the Health Commission of Northwest China (Shaanxi, Gansu, Ningxia, Qinghai and Xinjiang). We analyzed the characteristics in time and space distribution, age and gender. 【Results】 Totally 548 cases of COVID-19 were reported in Northwest China. The cumulative incidence rate was 0.53 per 100 000 people. The curative rate was 97.4% and the case fatality rate was 1.5%. Capital cities of each province had a higher incidence rate than that of other regions. The proportion of local transmission increased with time. The male-to-female ratio in the confirmed cases was 1.11∶1. Most patients were aged 20 to 60 years old. At the early stage most cases were imported from Hubei Province and later the pattern became local transmission. The average time interval between disease onset and hospital visit was (2.6±3.2)d. The average time interval between hospital visit and case confirmation was (4.8±3.1)d. The average time interval between centralized isolation and case confirmation was (6.1±4.0)d. 【Conclusion】 The epidemiological features of COVID-19 cases, including the basic situation, gender and age distribution and patient behaviors, were reviewed and analyzed. COVID-19 was well controlled in Northwest China, which indicates that the current preventive measures were effective. They will provide reference for future prevention.

Acute respimtory distress syndrome(ARDS)is an acute diffuse inflammatory lung injury caused by various internal and external lung injury factors.It has complex pathogenesis,rapid onset and high mortality,which seriously endangers human life and health.Pulmonary fibrosis is one of the important pathologic processes of ARDS occurrence and development,and it is also an important cause of death in ARDS patients.To a certain extent,the severity of pulmonary fibrosis in ARDS is determined by the dynamic balance of macrophage-fibroblast interactions.Therefore,this article aims to review the interaction mechanism of macrophage-fibroblasts in the pro-cess of ARDS pulmonary fibrosis,and provide new methods and ideas for the diagnosis and treatment of ARDS pul-monary fibrosis.