An overview of 2019 novel coronavirus COVID-19 pandemic: A review study

Abstract

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, was first reported in December 2019 in Wuhan, Hubei province, China. It is now known as a pandemic and a global crisis due to rapid human-to-human transmission with the vast expansion that has affected almost all countries. The primary source of the disease is still unknown, but it is possible that the virus was transmitted through bat to an intermediate host and then to humans. The main and early symptoms of COVID-19 infection are fatigue, fever, dry cough, myalgia, and dyspnea. The incubation period of the disease is about 2-14 days, which is one of the important parameters for planning to prevent disease outbreak. PT-polymerase chain reaction test is used to diagnose the disease; chest computed tomography scan, chest X-ray, blood tests, and symptoms are also very helpful in diagnosing the disease. There is a strong emphasis on controlling infections and hand hygiene to prevent the transmission of the disease. There is not enough knowledge about this disease yet, and there are no specific vaccines or medications available to prevent and treat this disease. The current review study uses articles indexed on databases of Embase, Elsevier, PubMed, and World Health Organization and Centers for Disease Control and Prevention, and keywords of coronavirus, COVID-19, acute respiratory distress syndrome and China.

Keywords: COVID-19; Infectious disease; SARS-CoV-2; epidemic; health emergency; novel coronavirus; pandemic; review.

Figure 1

Total number of infected cases in the United States on November 21, 2020; Source: World Health Organization website[42]

Figure 2

Active lesion in the lung of patient on admission on day 20 of the disease

Figure 3

No active lesion in the lung of patient A on admission on day 20 of the disease (a1) is seen, but in the same patient the upper right lung interstitial infiltration can be observed six days after admission (a2). In patient B, interstitial infiltration is seen on admission in the left lower lobe on day 15 of the disease (b1) and remains for five days after admission (b2). Source: Images adapted from Hsih et al.[51]