3 Clinical Characteristics

The fourth edition added “3 to 7 days, up to 14 days” in the description of the incubation period which has been further modified as “1 to 14 days,and generally within 3 to 7 days” in the fifth edition according to the results of epidemiological investigation.

The first edition described symptoms as “fever, fatigue, dry cough, etc.”and the fourth edition added “a few patients with symptoms such as nasal congestion, runny nose, and diarrhea”. With the understanding of pathogenesis of critical patients, the fourth edition emphasized that severe cases were usually aggravated one week after the onset of disease, accompanying with dyspnea, and the fifth edition added hypoxemiaas a severe manifestation.

As for mild cases, the fifth edition describes them separately and changes the “death cases more common in the elderly and those with chronic underlying diseases”in the fourth edition tothat “the elderly and those with chronic underlying diseases have a poor prognosis”.

The discription of that “the majority of patients have a good prognosis, a few patients are critically ill, and even die” has not be changed from the first to sixth editions.