Guidance for the management of adult patients with coronavirus disease 2019

[2,3] Etiology In December 2019, after an unexplained viral pneumonia epidemic emerged in Wuhan, the National Health Commission designated the Chinese Center for Disease Control and Prevention, the Chinese Academy of Medical Sciences, the Academy of Military Medical Sciences of the Academy of Military Sciences, the Hubei Provincial Center for Disease Control and Prevention, and the Wuhan Institute of Virology, Chinese Academy of Sciences, among others, as parallel testing units. Electron microscopy of autopsy specimens has revealed a large number of virus particles in alveolar epithelial cells, [1] and live virus particles have also been isolated from respiratory specimens and urine and stool samples. Light microscopic observation The main pathological changes noted in the lungs are a large number of macrophages and serous fibrous exudation in the alveolar cavity, accompanied with intra-alveolar hemorrhage [Figure 1]; diffuse alveolar damage, carnification in alveolar space, and pulmonary consolidation [Figure 2]; transparent membrane formation at alveolar cavity surface in some patients; Type II alveolar epithelium proliferation to varying degrees; alveolar septa widening to varying degrees and interstitial fibrous tissue proliferation, with a small amount of lymphocyte infiltration [Figure 3]; and retention of mucinous secretion and even mucus plugs in some small airways (mainly bronchioles and terminal bronchioles). Elderly adults and people with comorbidities, such as chronic obstructive pulmonary disease, diabetes, hypertension, and heart disease, have an increased risk of infection.