There are seven types of known coronaviruses in the world, according to the Centers for Disease Control and Prevention (CDC), which have often started in animals such as camels and bats. Usually, these coronaviruses don’t infect humans, but three newer types—SARS-CoV, MERS-CoV, and 2019-nCoV—have.
The 2019-nCoV strain of coronavirus of this most recent that spread in December 2019 is thought to have originated in snakes, according to a research article published in the Journal of Medical Virology on January 22. However, the CDC states that it still isn’t known why certain coronaviruses spread to people and others don’t. This most recent outbreak originated from a market in Wuhan, China, that sold seafood and live animals. (The Chinese government has since closed the market, Business Insider reported.)
“Corona means ‘crown,’ so these viruses appear crown-shaped when looked at under an electron microscope,” said Bhanu Sud, MD, an infectious disease specialist at St. Jude Medical Center in Placentia, California.
“Most coronaviruses are harmless,” he said. “They’ll usually cause mild to moderate upper respiratory tract illnesses, like the common cold. Most people will get infected with these viruses at some point in their lives.”
Sud emphasizes that while the outlook is good for most people infected with this type of virus, the SARS and the MERS strains are more serious.
The death rate is around 10 percent for people with SARS and 30 percent for those with the MERS variant.
“What is unknown right now is the virus being typed. They’re doing testing to find out what type of virus this is and whether it’s more similar to SARS or MERS,” Bhayani said. “I have a strong feeling that this is going to be a new virus.”