What causes foodborne illness most often?

Bacteria are the leading cause of foodborne illness because they can multiply rapidly in food under the right conditions, especially when food is improperly stored or inadequately cooked. Certain bacteria, such as Salmonella, E. coli, and Listeria, are well-known for causing significant outbreaks and illnesses. These microorganisms can be present in various food items, including raw meats, eggs, dairy products, and even fruits and vegetables, if they come into contact with contaminated surfaces or water.

While viruses, parasites, and fungi can also contribute to foodborne illness, bacteria account for a majority of reported cases and outbreaks. Viruses like norovirus and hepatitis A are indeed common, particularly in food handling and person-to-person transmission, but they do not proliferate in food the same way bacteria do. Parasites are less common overall and often require specific conditions or hosts to thrive. Fungi, while they can cause spoilage and some illness, are not the primary cause compared to bacteria. This makes understanding bacterial contamination and prevention crucial for food safety practices in any food service operation.