In December 2019, the world saw the appearance of a severe acute respiratory syndrome, SARS-CoV-2, in Wuhan. The virus originated in bats and was transmitted to humans. The number of cases started increasing exponentially. According to the World Health Organization, the massive migration of Chinese during the Chinese New Year fuelled the epidemic. Cases in other provinces of China, other countries (Thailand, Japan, and South Korea in quick succession) were reported in people who were returning from Wuhan. After two months, the World Health Organization reclassified this virus as a pandemic. This virus caused a great danger in the world; most countries declared a state of emergency and implemented quarantine in order to stop the spreading of the virus. We don't yet have an effective medicine against this virus. More than 155 million people are now infected with COVID-19 and more than three million people have died. This chapter will discuss the history and spread of the COVID-19 pandemic.
TopHistorical Insight Into Coronaviruses
Fred Beaudette and Charles Hudson isolated avian bronchitis virus (IBV) from birds in 1937 and called it avian bronchitis virus (ABV) (Henry & T, 2019). In addition, June Almeida and David Tyrrell isolated two strains from human nasal epithelium and trachea, HCoV229E and B814, which share major similarities with the IBV, thirteen years later, in 1967(Tyrrell & Almeida, 1967).Almeida coined the word “coronavirus” to describe the “solar corona” form disposition of surface viral glycoprotein spikes exposed under electronic microscopic analysis. The first human coronaviruses, HCoV229E and HCoVOC43, are now known as betacoronaviruses, and they cause mild respiratory tract infections (Bradburne et al., 1967; McIntosh et al., 1967).
Coronavirus research has declined significantly since the late 1960s, with only regular human testing remaining. As a result, data on the impact of human coronaviruses (HCoVs) on the respiratory tract has been under-reported, and epidemiological data has been scarce. Following the introduction of new HCoVs that cause extreme acute respiratory syndrome, new research on the clinical features of HCoV infections were launched in 2003. (SARS, induced by SARS-CoV). These first appeared in 2002 in Guangdong, China, and soon spread across the world, resulting in 8437 infections and 813 deaths(Zhong et al., 2003).
After that, two new HCoVfamily members were discovered, HCov-NL63 in New Haven in 2004 (Fouchier et al., 2004; Van Der Hoek et al., 2004)and CoV-HKU1 in a 71-year-old man with pneumonia after returning from Shenzhen, China in 2005(Fouchier et al., 2005).(Woo et al., 2005). During the winter, these viruses spread globally with a limited incubation period (Gerna et al., 2006). Newborns, babies, immunosuppressed patients, and the elderly are the most vulnerable targets for these viruses(Falsey et al., 2002). In September 2012, another outbreak occurred in Saudi Arabia, indicating that a member of the Beta coronavirus genus was responsible for the Middle East respiratory syndrome (MERS) (Assiri et al., 2013). SARS-CoV, which is highly infectious and lethal, began spreading in November 2002. It began in China and quickly spread around the world on international passenger transport routes, reaching 29 countries in a matter of months (Table 1).