Introduction
In December 2019, several cases of novel coronavirus-infected pneumonia
have been reported in Wuhan, a large city of 11 million people in China
[1-3]. Then, the novel coronavirus was identified by the Chinese
Center for Disease Control and Prevention from the throat swab and
bronchoalveolar lavage fluid samples of patients in Wuhan, and was next
named
COVID-19
by WHO [4]. The disease spread rapidly from Wuhan to other parts of
China. As of March 31, 2020, about 82,545
COVID-19-infected
patients in China have been confirmed. More than 50 countries have
reported confirmed cases worldwide. Most patients have mild symptoms and
good prognosis, while a few develop
severe
pneumonia, acute respiratory distress syndrome (ARDS), multiple organ
failure, or even death.
At present, several observational studies have offered information
regarding the epidemiology and clinical features of pneumonia caused by
COVID-19[5-13] Clinical manifestations of patients with
COVID-19-infected pneumonia mainly include fever, headache, muscle ache,
cough, dyspnea, fatigue, etc. A few
patients developed ARDS, and multiple organ failure (eg. shock, acute
cardiac injury, and acute kidney injury). However, data from different
studies also showed significant differences in the incidence of fever,
cough, dyspnea, etc. Huang et al found that the most common symptoms
were fever (98.6%), fatigue (69.6%), and dry cough (59.4%) at onset
of illness [6]. Less common symptoms were dizziness, headache,
abdominal pain,
etc.
Guan et al revealed that only a few patients had symptoms of fever
(43.8%) at onset of illness [10]. Accordingly, there are doubts
about the clinical significance of differences reported in the different
studies. We set out to meta-analyses of all available data from
observational studies in China to enable an objective reappraisal of the
clinical characteristics.