Another coronavirus, Another challenge

The world is yet again challenged by the outbreak of a new coronavirus, named SARS-CoV-2; disease caused by this virus, now termed as COVID-19,was first reported in Wuhan City, Hubei Province China in the last week of December 2019. As of march 5, WHO reports a total of 80,430 cases of COVID-19 with 3013 deaths from China. The disease has been now reported in all the continents of the world except Antarctica –around 15,053 cases in 85 countries with 273 deaths. Although many cases have been reported in India, whether it going to touch this part of the country too, only time will tell.  It is very likely that by the time this editorial goes in print, the numbers would have changed significantly. It is because of this developing outbreak situation that has engulfed the entire world and has the potential to turn into a pandemic, I decided to focus on this new disease than to comment on one of the many well written papers in this issue of the journal. Understanding of this novel coronavirus, SARS-CoV-2, is evolving. This virus belongs to a large family of viruses known as coronaviridae family which are enveloped positive stranded RNA viruses causing respiratory and enteric infections affecting both animals and humans. The animal species infected by various coronaviruses include camels, cattle, cats and bats. Although very uncommon, coronaviruses of animal origin can infect humans and then spread from person to person, sometimes with devastating morbidity and mortality as is the case with MERS-CoV. The other two animal coronaviruses infecting people are SARS-CoV and SARS-CoV-2. All these three viruses are betacoronaviruses and have their origin in bats1. Sequences from SARS-CoV-2 generated from patients outside China are similar to the original Chinese isolate suggesting a likely single emergence of SARS-CoV-2 from an animal reservoir. In the coming months we expect to learn more about the evolution and other pathogenetic aspects of the disease caused by SARS-CoV-2