（Definition[3]：Mild type: Mostly seen in children and young adults. The body temperature is below 38.0°C, with mild fatigue, general discomfort, and digestive symptoms. White blood cell and platelet counts are mildly reduced. The condition is self-limiting, usually recovering within a week, and is often overlooked, misdiagnosed, or missed；Moderate type: Mostly seen in middle-aged and elderly individuals. The body temperature is between 38-39°C, with obvious general discomfort and muscle soreness. There may be significant anorexia, nausea, vomiting, and diarrhea, but no neurological symptoms or cavity bleeding；Severe type: Mostly seen in the elderly, those with underlying diseases, or those who did not seek timely medical attention after falling ill. The body temperature is between 39-40°C or even above 40°C, with extreme fatigue, loss of appetite, indifferent expression, mental depression, and skin bruising. There may be involuntary movements of the jaw and limbs, accompanied by increased muscle tone, drowsiness, confusion, or lethargy. It may be complicated by pulmonary infection and bleeding in the digestive tract, lungs, and uterus；Critical type: This type has a dire prognosis and a very high fatality rate. Based on the severe type, it is characterized by one of the following conditions: 1. Coma, delirium, or repeated convulsions and other significant neurological symptoms; 2. Shock; 3. Complications with other organ failures requiring ICU monitoring and treatment.）