The SARS-CoV-2 Pandemic a Global Emergency: The Journey from Bats to Humans

Bats are considered as the reservoirs of coronaviruses (CoVs) which resulted in severe disease outbreaks in humans. Zoonotic coronaviruses responsible for Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), were originated from bats and remain highly pathogenic to humans during the last two decades. Recently, an acute respiratory disease outbreak which spread in Wuhan, China was caused by a novel coronavirus (SARS-CoV-2) also known as 2019-nCoV, received worldwide attention. The World Health Organization (WHO) officially declared the COVID-19 epidemic caused by SARS-CoV-2 as a public health emergency. The emergence of SARS-CoV-2 has been considered as the third highly pathogenic epidemic of the 21 st century. The SARS-CoV-2 belongs to β -coronavirus group with highly identical genome to bat coronavirus RaTG13, assuming bat as the natural host. According to WHO as of December 21, 2020, approximately 75,479,471 persons were infected with 16,86,267 deaths in 222 countries. Whereas the in Pakistan according to WHO as of December 21, 2020, around 4 57,288 persons were infected with 9, 330 death reported in the country.