Dr. Michael Ryan noted that "strains and viruses have moved around the world" throughout the virus pandemic and said the fact that a virus from Europe sparked China's latest outbreak did not mean the virus originated there."What it's saying most likely is that the disease was probably imported from outside Beijing at some point," Ryan said, adding that "establishing when that happened and how long the chain of transmission is, is important." He said that many coronavirus strains spreading in New York could also be linked to Europe.