What are the precursors to the onset symptoms of an epidemic

During the novel coronavirus pneumonia outbreak, the vast majority of patients had fever, dry cough, and malaise as precursors. Patients with novel coronavirus pneumonia mainly have symptoms of upper respiratory tract infection, such as nasal congestion, runny nose, sore throat, generalized body aches, loss of appetite, diarrhea, and malaise. Early symptoms are not specific, and signs such as dry cough, fever, and generalized malaise are usually present. In patients with mild cases of novel coronavirus pneumonia, only low-grade fever and mild malaise are present, with no signs of pneumonia, and there are no significant changes in early chest radiographs. In severe cases, patients with novel coronavirus pneumonia may present with respiratory distress or hypoxemia, and in severe cases, septic shock, acute respiratory distress syndrome, uncorrectable metabolic acidosis, and disseminated intravascular coagulation. Lung chest radiographs may show ground glass shadows in the outer bands of both lungs. The patient’s lung function decreases rapidly and the symptoms of dyspnea are more pronounced. Under the influence of the novel coronavirus pneumonia outbreak, anyone who has been in close contact with patients with novel coronavirus pneumonia and asymptomatic infected persons or has been to a crowded place needs to pay close attention to whether there are symptoms of fever, cough, diarrhea, and so on. If any of these symptoms occur, immediately go to the hospital fever clinic. Tip: “New coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.