These finds are based on antibody detection.
Also I believe France suspected the same thing based on going back through its records.
Patient is named.
Was there COVID-19 in France last November? - CGTN
I was in Scotland the end of last September and got sicker than a dog about 3 days before we were scheduled to leave. Came home and spent almost 2 weeks in bed. I’ve said since then that I think I had Covid. My friend that travels with me said she’d never seen anyone be so sick with a ‘cold’.