Scientific sleuths are closing in on the true source and timing of the Covid-19 coronavirus outbreak in the United States.

And it looks like the virus arrived earlier — weeks, possibly months, earlier — than the first identified U.S. case of the disease, a man who had traveled to Wuhan, China and returned to his home near Seattle in mid-January.

“There are increasing signs that the virus had begun its global spread long before it was identified,” reports The Hill. “French scientists on Monday published the results of a study that found coronavirus present in samples given by a resident of a Paris suburb who was tested Dec. 27.”

That was four days before China identified the Covid-19 cluster in Wuhan.

The French patient had not traveled outside the country since the previous August, meaning the virus could have reached France even earlier; he may have been infected by one of his own children, “further back-dating the point at which the virus had spread to Europe,” The Hill says.

In fact, the political website says, it’s likely the virus outbreak began “long before Chinese officials got the first indications of a new pathogen in their midst.”

Scientists work hard to trace any new virus to its root cause. For the Covid-19 virus, aka SARS-CoV-2, they especially want to know how it made the leap from animals (bats are suspected) to humans. That would help them determine how best to prevent such transfers in the future.

According to a growing body of research, SARS-CoV-2 is almost certainly a naturally occurring virus that initially circulated in bats then spilled into humans.

But that hasn’t stopped some from trying to find a more sinister origin. https://t.co/hO0RXeXFTU

— ABC News (@ABC) May 5, 2020

President Trump has suggested, without evidence, that the virus escaped from a Wuhan biological laboratory, even that it was intentionally leaked.

Newsday’s editorial board calls that “campaign fodder,” saying Trump “intends to run for reelection by blaming China for the virus, deflecting from his own inadequate response to the pandemic.”

As for the virus’s arrival in the U.S., experts now suspect it was already spreading among Americans late last year, with many who were infected showing few symptoms or none at all.

“It wouldn’t surprise me if it was here in December,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

“The horse was long out of the barn before anybody thought to close the barn door.“