The Coronavirus pandemic outbreak was first identified in Wuhan, Hubei, China, in December 2019, and was recognized as a pandemic by the World Health Organization (WHO) on 11 March 2020.
A cluster of pneumonia cases of unknown cause was reported by health authorities in Wuhan, the capital of Hubei province in China on December 31, 2019, and an investigation was launched in early January 2020. These cases mostly had links to the Huanan Seafood Wholesale Market, which also sold live animals. Consequently, the virus is thought to have a zoonotic origin.
It is believed that the Coronavirus pandemic of 2019-20 may have originated in horseshoe bats (genus Rhinolophus).
The 2019-20 coronavirus pandemic has been caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). More than a decade and a half earlier, between November 2002 and July 2003, an outbreak of SARS in southern China caused by SARS-Coronavirus, which led to an eventual 8,098 cases, resulting in 774 deaths reported in 17 countries. That viral outbreak was genetically traced to a colony of cave-dwelling horseshoe bats in China’s Yunnan province.
5Wuhan Institute of Virology
Wuhan which became the first epicenter of the COVID-19 outbreak also has a Research Institute of Virology. Immediately after the news of coronavirus outbreak, the Institute was rumored to be a bioweapon research laboratory and there were concerns worldwide that it was the source of the outbreak through accidental leakage, which it publicly refuted. Though virus experts have observed that “the mutations [in the virus] are completely consistent with natural evolution,”(ruling out bioweapon attack) they agree that a laboratory accident cannot be ruled out completely.
Researchers found that 80% of COVID-19 cases spread from people who don’t know they are sick. Research has also found that infected patients are contagious 2 days before symptoms show.
People infected by COVID-19 may either be asymptomatic or develop flu-like symptoms such as fever, cough, fatigue, shortness of breath, or muscle pain. CDC lists emergency symptoms including difficulty breathing, persistent chest pain or pressure, sudden confusion, difficulty waking, and bluish face or lips. Immediate medical attention is advised if these symptoms are present.
The usual incubation period (the time between infection and symptom onset) ranges from one to fourteen days. It is most commonly five days. In one recorded case, however, it had an incubation period of 27 days.
9Method of Spread
The coronavirus (COVID-19) seems to mostly spread between people via respiratory droplets. It may also be spread from touching contaminated surfaces and then touching one's face. Researchers have discovered that coronavirus can live up to 72 hours on certain materials such as stainless steel, up to 3 hours in the air and it can likely live up to 96 hours on phone screens.
The Novel Coronavirus-19 uses the ACE2 receptor for entry into target cells. It is a receptor involved in regulating blood pressure. ACE2 receptor is not expressed as prominently in young children as in adults, which makes it tougher for the spikes on the tiny viral particles to bind and gain entry to the cells so that the virus can replicate.