evidence: - Biological hazards include bacteria, viruses, and parasites. Bacteria and viruses are responsible for most foodborne illnesses. Biological hazards are the biggest threat to food safety. They can be inherent in the product or due to mishandling (e.g., time/temperature abuse). [...] Viruses are the smallest known organisms. They cannot multiply in food—they need a human host. Viruses are transmitted to food from infected people. [...] Pathogens can cause different types of foodborne illness. Once a contaminated food is eaten, illness can be caused by the pathogens themselves (foodborne infection); caused by toxins produced in the food by pathogens (foodborne intoxication); and caused by toxins produced in the body by pathogens (foodborne toxin-mediated infection).