Sick restaurant employees are a common cause of sick customers. When a cook, server, or other restaurant worker is sick, they can transfer the illness to you. In some cases, managers know the employee is sick but still allow -- or even require -- them to work handling food. According to a study by the Environmental Health Specialists Network (EHS-Net), 12% of food service workers reported working when they were sick with vomiting or diarrhea. These service workers are more likely to work when they are sick when the restaurant: Is busy; Does not have a policy that requires workers to tell a manager when they are sick; Does not have on-call or replacement workers available; or Has a manager with less than 4 years experience. Unfortunately, when a sick restaurant employee gets you sick, it can be difficult to identify the person responsible for passing on the illness. Illnesses like a cold or flu can take days to show symptoms. By that time, you may not know where the germs came from.