Snakes may be the source of the new coronavirus outbreak in humans that started in China and has spread to other countries.
Patients who became infected with the virus - named 2019-nCoV by the World Health Organization - were exposed to wildlife at a wholesale market where seafood, poultry, snakes, bats and farm animals were sold, researchers report.5 things you need to know about the latest strain of coronavirus
The Chinese scientists, led by Wei Ji, from the Department of Microbiology at Peking University Health Science Center School of Basic Medical Sciences in Beijing, conducted a detailed genetic analysis of the virus. They concluded that it appears to have formed from a combination of a coronavirus found in bats and another coronavirus of unknown origin.
The mystery coronavirus developed a mix (recombination) of a viral protein that recognises and binds to receptors on host cells, which enables the virus to enter host cells and cause infection and disease, the researchers explained.
They also found evidence that 2019-nCoV was likely present in snakes before appearing in humans. Recombination within the viral receptor-binding protein may have enabled the virus to jump from snakes to humans, according to the study. It was published online January 22 in the Journal of Medical Virology.
"Results derived from our evolutionary analysis suggest for the first time that snake is the most probable wildlife animal reservoir for the 2019-nCoV," the authors wrote in a journal news release.
"New information obtained from our evolutionary analysis is highly significant for effective control of the outbreak caused by the 2019-nCoV-induced pneumonia."
Cases of human infection with the new coronavirus were first reported in the city of Wuhan, China, in late December. According to AFP, Since then, 830 cases have been reported, with at least 25 deaths.
On Thursday, Chinese health officials banned travel in Wuhan and four other nearby cities in an effort to stem the spread of the virus.
One case has been reported so far in the United States, and all visitors from Wuhan will now be screened at five US airports: San Francisco, New York City, Chicago, Atlanta and Los Angeles.
This latest coronavirus and other emerging viral infections such as bird flu, Ebola and Zika pose significant worldwide health threats. Learning about their origins can help researchers develop measures to defend against future outbreaks.
Control of emerging viral infections requires the discovery and development of effective vaccines and/or antiviral drugs, but currently licensed antiviral drugs should still be tested against 2019-nCoV, an editorial published with the study suggests.
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