You probably have to avoid eating soup altogether with that kind of mentality.
Even if you get your own bowl of soup, do you know the soup that you are about to eat may have already been accessed by many people prior to serving it to you?
I've seen chefs at noodle restaurants in Laos take turns tasting soup in a large pot to make sure the flavour is right.
Other cultures is no different to Lao. In the movie, Meet Me in St. Louis, the ketchup was accessed by about half a dozen people with the same scoop spoon then they dip it back in to stir it. This ketchup was then served on individual plates as a soup course.
Judy Garland as Esther Smith tasting ketchup