3.1. Clinical manifestations
Based
on the current epidemiological
investigation,
the incubation period of the COVID-19 is about 1-14
days(Linton et al., 2020a). The main
manifestations are fever, dry cough and fatigue and some patients had
nasal congestion, runny nose, myalgia and
diarrhea(Linton et al., 2020b). According
to the severity of symptoms,
COVID-19
can be divided into four classes: mild, moderate, severe, and
critical(Zu et al., 2020). Mild patients
only presented low-grade fever, mild fatigue or dry cough only. Moderate
always characterized by fever, respiratory symptoms, and radiographic
features.
The
severe patients should meet one of these criteria: A. dyspnea B.
PaO2/FiO2<300 mmHg. C. Oxygen saturation <93% in
ambient air (Z. Sun, Thilakavathy, Kumar,
He, & Liu, 2020). And about half of the patients may develop into
critical patients with acute respiratory distress syndrome, septic
shock, and coagulation dysfunction within a
week(Gorbalenya, 2020). According to the
recent survey conducted by China
CDC,
80.9% of the confirmed patients (44672) were mild pneumonia cases,
13.8% were severe cases, and 4.7% were critical cases. It had been
revealed that the fatality rate of critical patients was
49%(Wang, Wang, Chen, & Qin, 2020).
Patients with basic diseases such as chronic respiratory disease,
cardiovascular disease, diabetes, cancers, would developed into ARDS and
worsened in a short period of time even died of multiple organ failure
and have a higher case fatality rates than those without. Current
reported data revealed that 86.6% of confirmed patients were aged 30-79
years and 1-2% of the patients were children and newborns (1.5 months
to 17 years), and most of whom had a close contact with infected cases
or were family cluster cases. In fact, Infected children might appear
asymptomatic or present with fever, dry cough, and fatigue, and few
presented with gastrointestinal symptoms including abdominal discomfort,
nausea, vomiting, abdominal pain, and
diarrhea(Shen et al., 2020). Most of them
recovered within 1–2 weeks after disease onset. In general, children
always presented with relatively mild symptoms and have a good
prognosis(J. F.-W. Chan, Yuan, Kok, To,
Chu, Yang, Xing, Liu, Yip, & Poon, 2020). The clinical course of
pregnant women with the COVID-19 is similar to patients of the same age.