If the airport workers had travelled to another country, their doctors would have looked for tropical/travel diseases.

Usually, it is through shipping containers where unwanted insects cross borders. That's how murder hornets and flying cockroaches got into the US.

I'm asking about the Dutchman story the parent wrote. I can hardly believe it tbh. Even if the Netherlands don't have specialized personel, Hamburg is just a 5 hour drive away and Antwerp even closer.