The detail is his wife worked at a supermarket near the main Paris airport, and had often had travellers (inc. from China) coming in, straight off the plane [0]

The detail is his wife worked at a supermarket near the main Paris airport, and had often had travellers (inc. from China) coming in, straight off the plane [0]. So one suggestion is she was caught it and was asymptomatic, and he caught it from her. [0] https://www.bbc.co.uk/news/world-europe-52526554 https://www.bbc.co.uk/news/world-europe-52526554