What is the primary mode of transmission of microorganisms to food and food contact surfaces?

The answer;

Through hands;

The primary mode of transmission of microorganisms to food contact surfaces is your hands.

Explanation;

Hands are contaminated through the touching of other parts of the body, using the restroom, Handling or caring for animals, coughing, sneezing, blowing nose, handling raw meat/poultry, Handling garbage/dirty dishes, Handling money, among other ways.

Contaminated hands in turn contaminate food and food contact surfaces.