3 Clinical Characteristics

The incubation period of COVID-19 is 1 to 14 days, and generally within 3 to 7 days. Fever, fatigue and dry cough are considered the main manifestations along with symptoms such as stuffy nose, runny nose, and diarrhea in a few patients. Because some severe patients have no obvious dyspnea and present with hypoxemia, the text is changed to “In severe cases,dyspnea and/or hypoxemia usually occurs after a week of disease onset, and the worse can rapidly progress to acute respiratory distress syndrome, septic shock, metabolic acidosis that is hard to balance, and hemorrhage and coagulation dysfunction, etc.”.This edition highlights that “Mild patients only present with low fever, mild fatigue and so on, but without manifestation of pneumonia”.

In terms of laboratory examination, this edition adds the following descriptions, “Increased values of liver enzymes, LDH, muscle enzymes and myoglobin can occur in some patients; and raised level of troponin can be seen in some critical patients” and “The nucleic acid of 2019-nCoV can be detected in biological specimens such as nasopharyngeal swabs, sputum, secretions of lower respiratory tract, blood and feces”.

In the early stage of COVID-19, the images show that there are multiple small patches shadows and interstitial changes, especially in the lung periphery. As the disease progresses, the images of these patients further develop into multiple ground glass shadows and infiltration shadows in both lungs. In severe cases, lung consolidation may occur. It is seldom to find pleural effusion in patients with COVID-19.