The roots of the potentially deadly novel coronavirus that emerged in humans in Wuhan, China, and is spreading to other countries lie in snakes, according to a genetic analysis published online January 22 in the Journal of Medical Virology.
The novel coronavirus -- dubbed 2019-nCoV -- causes respiratory illness and can be fatal. A detailed genetic analysis showed that it formed from a coronavirus found in bats and another coronavirus with unknown origin. Most likely, it was transmitted through snakes to humans, the researchers noted in a statement.
"Recombination within the viral receptor-binding protein may have allowed for cross-species transmission from snake to humans," they explained.
People who have been infected in China were reportedly exposed to wild animals at a wholesale market, including bats and snakes.
Hundreds of cases of the novel coronavirus have been detected in China, and the outbreak has spread to several other countries, with human cases confirmed in Thailand, Taiwan, Japan, and South Korea, according to the U.S. Centers for Disease Control and Prevention (CDC). Eighteen deaths had been reported as of January 23.
On January 21, the CDC reported the first U.S. case, in a traveler returning from Wuhan, who was treated successfully. The agency is urging caution as the news unfolds, noting that some viruses, such as measles, are highly contagious, but others are less so.
"It's not clear yet how easily 2019-nCoV spreads from person-to-person," the agency advised. "It's important to know this in order to better assess the risk posed by this virus."
In the U.S., testing for the virus is centered at CDC labs, and the agency said it plans to share tests with domestic and international partners "in the coming days and weeks."