I may be paranoid but salad bars have never been appealing to me. The lettuce alone sits there sometimes for long periods of time and the temperature is almost impossible to maintain to be constant at less than 40 degrees. F. Anything above that for cold foods is called the danger zone for microbe growth. That zone is so important in practicing food safety principles and your health.
Note: The coronovirus itself has never been implicated in any food safety issue to my knowledge. However, until it is determined what its modes of transmission are beyond any doubt, food safety is a good idea for general healthy principles anyway.