Michelle Roberts

Health editor, BBC News online

Could coronavirus have been circulating in Europe in late 2019, many weeks before it was officially recognised and declared a threat there? That is the suggestion being made after a French doctor has revealed that he treated a patient in Paris with all of the symptoms of coronavirus just after Christmas.

How does this change what we know about the pandemic? It might be that the test result is an error and so does not change a thing.

But it if is correct, it could mean spread of the disease was going unchecked in Europe while all eyes were on the East in Wuhan.

Certainly, any laboratories in Europe with samples from patients sick with similar symptoms around that time might want to run a test for coronavirus to see what it reveals so that we can learn more about this new disease.