Chapter 2 - COVID-19 Pandemic: Animal Cross Talk and Comparison Between nSARS-CoV-2 and Animal Coronaviruses

Abstract

Coronaviruses (CoVs) belong to a large family (Coronaviridae), have a global distribution, and cause respiratory and intestinal infections in animals, birds, and humans. Usually, these viruses cause common cold, which is typically mild in humans, although rarer forms such as severe acute respiratory syndrome and Middle East respiratory syndrome can be lethal. CoVs cause an upper respiratory disease in chickens, but diarrhea in cows and pigs. The newly emerging pandemic, the coronavirus disease 2019 (COVID-19), is caused by the novel severe acute respiratory syndrome coronavirus 2 (nSARS-CoV-2), which first appeared in Wuhan, China, in December 2019 and thereafter spread throughout the globe and declared as a pandemic disease by the World Health Organization. It has been postulated that the virus was transmitted to humans from bats through an evolutionary process termed as ‘host jump’, resulting in a cross talk about animal-human interface and zoonotic links of nSARS-CoV-2 and urging an intensive investigation of the involvement of animals or birds. Later, several animals such as dogs, cats, tigers, pangolins, ferrets, and minks were found to be naturally infected with nSARS-CoV-2. Additionally, laboratory animals such as mice, ferrets, and monkeys were successfully infected with the virus. Animal CoVs share some common features with nSARS-CoV-2. Although nSARS-CoV-2 is of animal origin, the roles of animals in the course of the pandemic are still elusive. This chapter discusses the predicted roles of animals in the COVID-19 pandemic, along with comparisons of nSARS-CoV-2 with other animal CoVs.