(CNN)Researchers studying the new UK strain of the coronavirus think it likely arrived in the US in mid-November, and that many people in the United States could already be infected.”If I had to guess, I would say it’s probably in hundreds of people by now,” said Michael Worobey, head of the department of ecology and evolutionary biology at the University of Arizona. “It’s very possible it’s arrived multiple times in multiple places.”
“Imagine the amount of infected travelers leaving London — that’s been increasing exponentially,” said Trevor Bedford, associate professor in the vaccine and infectious disease division of the Fred Hutchinson Cancer Research Center.
British scientists have traced the new strain’s earliest known appearance back to September 20 in Kent, a county southeast of London.Worobey and Bedford say they estimate the virus would have arrived in the US in mid-November.Both scientists, as well as others around the world, have scoured genetic sequences of coronavirus in the United States to see if any match up with the UK variant. So far, they haven’t found any, but they say that’s likely because the US surveillance system isn’t catching them.Health officials agree.