Photo by Claudio Foco.

2020 greeted us with an outbreak of 2019-nCoV most commonly known as coronavirus. Wuhan is the capital of Hubei and is the seventh-largest city in China, with a population of more than 11 million people. It has been a major transport hub of the country throughout the ages, long known as the “Nine Provinces’ Thoroughfare” and now as the epicenter of the outbreak. During December 2019, a cluster of cases displaying the symptoms of a “pneumonia of unknown cause” was linked to Huanan Seafood Wholesale Market, which had a thousand stalls selling fish, chickens, pheasants, bats, marmots, venomous snakes, spotted deer, and other wild animals. In January 2020, the hypothesis was that this was a novel coronavirus from an animal source. Coronaviruses mainly circulate among other animals but have been known to evolve and infect humans as in the cases of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) together with four further coronaviruses that cause mild respiratory symptoms similar to the common cold. 2019-nCoV’s genome sequence is 75- to 80-percent identical to SARS-CoV, and more than 85-percent similar to several bat coronaviruses.All coronaviruses known to infect humans have been shown to spread between people. Transmission of coronaviruses is primarily thought to occur among close contacts via respiratory droplets generated by sneezing and coughing. Those infected may be asymptomatic or have mild to severe symptoms, like fever, cough, shortness of breath, and diarrhea.The time from exposure to onset of symptoms is estimated at 2 to 10 days by the World Health Organization, and 2 to 14 days by the US Centers for Disease Control and Prevention (CDC). Upper respiratory symptoms such as sneezing, a runny nose or sore throat are less frequent.Cases of severe infection can result in pneumonia, kidney failure, and death. The natural wildlife reservoir of the 2019‐nCoV and intermediate host that transmitted the 2019-nCoV to humans has not been confirmed. However, it is likely that the primary reservoir for the virus is bats. Research suggests that the 2019 novel coronavirus has possible bat origins, as 2019-nCoV is 96% identical at the whole genome level to a bat coronavirus identified in 2013. Earlier reports that snakes might have been the natural reservoir for the virushave been widely disputed. Some argued that the reservoir must be bats and the intermediate host, bird or mammal, not snakes (as snakes, unlike humans, are poikilotherms), while others used data on recombination and SARS/MERS codon usage bias to refute the reasoning. The recombination event mentioned probably happened in bats. The phylogenetic tree showed that 2019-nCoV significantly clustered with a Bat SARS-like Coronavirus sequence, whereas structural analysis revealed mutations in Spike Glycoprotein and nucleocapsid protein. The authors concluded 2019-nCoV is a coronavirus distinct from SARS virus that probably was transmitted from bats or another host that provided the ability to infect humans.

Story by Travis Orta.