Introduction
Coronavirus disease (COVID-19) is an infectious disease caused by a
newly discovered coronavirus, the severe acute respiratory syndrome
coronavirus-2 (SARS-CoV-2) (Lai et al., 2020).
An outbreak of COVID-19 has spread
worldwide. As of June 3, 2020, SARS-CoV-2 has
caused 6.35 million infections and
more than 380 thousand deaths in the world, according to the World
Health Organization.
Mild symptoms associated with COVID-19 are mostly fever, tiredness, and
dry cough. Symptoms remain mild throughout infection in the majority of
patients. However, mild cases can develop into severe cases of viral
infections in the patients’ respiratory tracts become worse. Severe
cases will have most likely developed pneumonia, acute respiratory
distress syndrome, respiratory failure, shock, and other organ failures
or risk of death (Wang et al., 2020; Wang et al., 2020; Zhou et al.,
2020). The case fatality rate
(CFR) is persistently increasing, and it is urgent to evaluate risk
factors associated with severe cases as the pandemic evolves. Earlier
intensive surveillance and treatment can then be performed to decrease
the CFR.