The countries reporting it so far have advanced medical systems that have the ability to detect it. That ability is a stark diving line between have and have not.

It's likely incubating everywhere.

Also remember, the "advanced systems" in places like the UK, France, Scandinavia and Israel are very "thin" and not "deep" as they are in places like Russia and the US that have extensive bio warfare research operations.

They are all like to boast of being world class but only the US, Russia and Japan can actually boast of having a surplus advanced medical capability. Certainly not China or India.