On February 24, 2009 the Nebraska Department of Health and Human Services identiﬁ ed an outbreak of Salmonella serotype Saintpaul . More than 125 people fell ill, reporting symptoms that included abdominal cramps, headaches, fever and diarrhea. Health ofﬁ cials in Nebraska and Iowa conducted a case-control study to identify whether the outbreak could be associated with a particular food item or restaurant. While casecontrol studies do not prove cause and effect, they can characterize a relationship, and thus provide information regarding disease etiology and disease patterns within a population. Analysis of this data can therefore help health ofﬁ cials identify possible point sources or contaminating agents.