The Centers for Disease Control and Prevention estimates that 76 million cases of foodborne illness occur in the U.S. each year; 5,000 are fatal. Most of these illnesses are caused by a variety of bacteria, viruses, and parasites and the remaining are poisonings triggered by harmful toxins or chemicals. To Jack Guzewich, a foodborne disease epidemiologist with the Food and Drug Administration's Center for Food Safety and Applied Nutrition, every outbreak is a new mystery. The mysteries unravel as Guzewich discovers how foods become contaminated and works to prevent similar outbreaks in the future. In an interview, Guzewich talks about food epidemiology, describes his job, and offers pieces of advice for students who interested in public health careers.